{"id":571,"date":"2020-06-10T18:19:33","date_gmt":"2020-06-10T18:19:33","guid":{"rendered":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/?post_type=chapter&#038;p=571"},"modified":"2022-01-04T20:06:45","modified_gmt":"2022-01-04T20:06:45","slug":"stages-of-development","status":"publish","type":"chapter","link":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/chapter\/stages-of-development\/","title":{"raw":"Stages of Development","rendered":"Stages of Development"},"content":{"raw":"<div class=\"PageContent-ny9bj0-0 iapMdy\">\r\n<div id=\"main-content\" class=\"MainContent__HideOutline-sc-6yy1if-0 bdVAq\">\r\n<div id=\"aa700c98-2a9e-4bb8-b838-6cb4f461d12a\">\r\n<div id=\"80731\" class=\"ui-has-child-title\"><section>\r\n<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">Learning Objectives<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nBy the end of this section, you will be able to:\r\n<ul>\r\n \t<li>Describe the stages of prenatal development<\/li>\r\n \t<li>Identify factors that influence prenatal development<\/li>\r\n \t<li>Explain theories of cognitive and psychosocial development<\/li>\r\n \t<li>Describe the major changes that occur in adolescence<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<\/section><\/div>\r\n<p id=\"fs-idp10820480\">Development\u202ffrom conception into a\u00a0fully grown\u00a0human involves\u202fmajor\u202falterations\u202fto anatomy, physiology,\u202fcognition, and\u202fbehaviour, and many of these\u202fchanges follow a\u202fpredictable,\u202fage-based\u202fprogression.\u202fThis\u202fsection will\u202fdiscuss prenatal, infant, child, adolescent, and adult development\u202facross three domains: physical, cognitive, and psychosocial.<\/p>\r\n\r\n<section id=\"fs-idm56322048\">\r\n<h3>Prenatal Development<\/h3>\r\nHow did you come to be who you are? From beginning as a one-cell structure to\u00a0your\u00a0birth, your\u202fprenatal development\u202foccurred in an orderly and delicate sequence.\u202fThere are three\u202fmain\u202fstages of prenatal development: germinal, embryonic, and fetal.\u202fLet\u2019s\u202fexplore\u202fwhat happens to the developing baby in each of these stages.\r\n\r\n<section id=\"fs-idp18677712\">\r\n<h4>Germinal Stage (Conception\u2013Week 2)<\/h4>\r\nEach biological parent\u202fcontributes\u202fDNA\u202fat the moment\u202fof conception,\u202fwhen sperm\u202fand\u202fegg\u202funite to\u202fform a\u202fsingle-celled\u202fzygote (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-2-lifespan-theories#Figure_09_02_Conception\" target=\"_blank\" rel=\"noopener\">Figure LD.7<\/a>).\u202fGrowth and development of the zygote\u202fare\u202fguided by\u202fthese inherited\u202fgenetic instructions, coded in DNA within\u00a046 chromosomes, 23 from each parent.\u202fIn mammals, sex is determined by contribution of specific chromosomes, females are typically XX and males are typically XY, so it\u2019s the\u00a0male parent\u2019s\u00a0contribution that determines genetic sex, a female parent only has\u00a0Xs\u00a0to contribute.\r\n\r\n[caption id=\"attachment_2228\" align=\"aligncenter\" width=\"1024\"]<img class=\"wp-image-2228 size-large\" src=\"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-content\/uploads\/sites\/21\/2020\/06\/LD7-1024x388.png\" alt=\"Side by side photos. Left photo shows microscope image of sperm fusing with ovum. Right image shows 23 pairs of chromosomes in an array.\" width=\"1024\" height=\"388\" \/> Figure LD.7 (a) Sperm and ovum fuse at the point of\u202fconception. (b) 23 pairs of human chromosomes inherited from each parent, box displays the sex chromosomes; one large X and a smaller Y in this individual.[\/caption]\r\n<figure><\/figure>\r\n<div id=\"Figure_09_02_Conception\" class=\"os-figure\">\r\n<div>During the first week after conception, the zygote divides and multiplies, going from a one-cell structure to two cells, then four cells, then eight cells, and so on. This process of cell division is called\u202fmitosis. Mitosis is a fragile process, and fewer than one-half of all zygotes survive beyond the first two weeks (Hall, 2004). After 5 days of mitosis there are 100 cells, and after 9 months there are billions of cells. As the cells divide, they become more specialized, forming different organs and body parts. In the germinal stage, the mass of cells\u00a0has\u00a0yet to attach itself to the lining of\u202fthe\u202futerus. Once it does, the next stage begins.<\/div>\r\n<div><\/div>\r\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1em;font-style: italic;font-weight: bold\">Embryonic Stage (Weeks 2\u20138)<\/span><\/div>\r\n<\/div>\r\n<\/section><section id=\"fs-idp59294704\">After the zygote divides for about 7\u201310 days and has 150 cells, it travels down the fallopian tubes and implants itself in the lining of the uterus. Upon implantation, this multi-cellular organism is called an\u202fembryo.\u202fBlood vessels grow, forming the placenta,\u202fa structure connected to the uterus that provides nourishment and oxygen\u202fto the developing embryo via the umbilical cord. Basic structures of the embryo start to develop into areas that will become the head, chest, and abdomen. During the embryonic stage, organs form and begin to function, at this stage there is a detectable\u202fheart-beat. The neural tube forms along the back of the embryo, developing into the spinal cord and brain.<\/section><section id=\"fs-idp44106368\">\r\n<h4>Fetal Stage (Week 8-9 - Onward)<\/h4>\r\n<p id=\"fs-idp100731664\"><span style=\"text-align: initial;font-size: 1em\">At\u00a0about nine weeks, the embryo\u202fbecomes\u202fa fetus. At this stage, the fetus is about the size of a\u00a0kidney bean and begins to take on the recognizable form of a human being.\u00a0It's during the fetal stage that the sex organs begin to differentiate. At about 16 weeks, the fetus is approximately\u00a04.5 inches\u00a0long. Fingers and toes are fully developed, and fingerprints are visible. By the time the fetus reaches the sixth month of development (24 weeks), it weighs up to\u00a01.4 pounds.\u00a0Hearing has developed, so the fetus can respond to sounds. The internal organs, such as the lungs, heart, stomach, and intestines, have formed enough that a fetus born prematurely at this point has a chance to survive outside of\u202fthe\u202fwomb. Throughout the fetal stage the brain continues to grow and develop, nearly doubling in size from weeks 16 to 28. Around 36 weeks, the fetus is almost ready for birth. It weighs about 6 pounds and is about 18.5 inches long, and by week 37\u202fall of\u202fthe fetus\u2019s organ systems are developed enough that it could survive outside the uterus without many of the risks associated with premature birth. The fetus continues to gain weight and grow in length until approximately 40 weeks. By then, the fetus has very little room to move\u202faround\u202fand birth becomes imminent. The progression through the stages is\u00a0shown\u202fin\u00a0<\/span><a class=\"autogenerated-content\" style=\"text-align: initial;font-size: 1em\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_02_Stages\">Figure LD.8<\/a><span style=\"text-align: initial;font-size: 1em\">.<\/span><\/p>\r\n\r\n<div id=\"Figure_09_02_Stages\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"731\"]<img id=\"38919\" src=\"https:\/\/openstax.org\/resources\/1752bba5757c2d2e2f43fb7a6d4a3baf7abfd135\" alt=\"The growth of a fetus is shown using nine pictures in different stages of development. For each stage, there is a picture of a fetus which gets progressively larger and more mature. The first stage is labeled \u201c9 weeks; fetal stage begins.\u201d The second stage is labeled \u201c12 weeks; sex organs differentiate.\u201d The third stage is labeled \u201c16 weeks; fingers and toes develop.\u201d The fourth stage is labeled \u201c20 weeks; hearing begins.\u201d The fifth stage is labeled \u201c24 weeks; lungs begin to develop.\u201d The sixth stage is labeled \u201c28 weeks; brain grows rapidly.\u201d The seventh stage is labeled \u201c32 weeks; bones fully develop.\u201d The eighth stage is labeled \u201c36 weeks; muscles fully develop.\u201d The ninth stage is labeled \u201c40 weeks; full-term development.\u201d\" width=\"731\" height=\"763\" \/> Figure LD.8\u00a0During the fetal stage, the baby's brain develops and the body adds size and weight, until the fetus reaches full-term development.[\/caption]<\/figure>\r\n<\/div>\r\n<\/section><\/section><\/div>\r\n<\/div>\r\n<\/div>\r\n<section id=\"fs-idm38503568\">\r\n<div id=\"fs-idm27510448\" class=\"psychology what-do-you-think ui-has-child-title\"><header>\r\n<h4><em>Reproductive Development and Sex Assignment<\/em><\/h4>\r\n<section id=\"fs-idm38503568\">\r\n<p id=\"fs-idp65129824\">The first step in differentiation of the reproductive organs happens with a sexless collection of cells at an area called the germinal ridge. In mammals, the main determinant of the pathway the germinal ridge follows is the SRY gene on the Y chromosome. This gene leads to the growth and specialization of cells in the inner portion of the germinal ridge, which eventually become the testes. In the absence of this gene, as in XX individuals, the outer part of the germinal ridge develops into ovaries. Both the testes and ovaries are\u00a0<strong>gonads<\/strong>, reproductive organs that contain reproductive hormones and gametes (sperm or eggs). In most XY individuals, high levels of fetal androgens, like testosterone, released from the testes promote development of the external\u00a0<strong>genitals<\/strong>\u00a0into a penis. In the absence of testosterone, as in most XX individuals, this same tissue becomes a vagina.\u00a0The practice of sexing newborn infants in this way has historically led misclassification of intersex people. Therefore, the terms\u00a0<em>assigned female at birth<\/em>\u00a0(<strong>AFAB)<\/strong>\u00a0and\u00a0<em>assigned male at birth<\/em>\u00a0(<strong>AMAB<\/strong>) describe biological sex more accurately than female and male, since it includes intersex individuals. This terminology is preferred by many members of transgender, intersex and non-binary communities since it acknowledges an individual\u2019s medical history and allows a distinction between biological sex and gender identity.<\/p>\r\n\r\n<div id=\"Figure_09_02_Prenatal\" class=\"os-figure\"><\/div>\r\n<div id=\"zip-idm242576096\" class=\"psychology dig-deeper ui-has-child-title\"><section>\r\n<div class=\"os-note-body\">\r\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">DIG DEEPER<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<h4>Understanding Gender<\/h4>\r\nGender refers to the way in which one perceives themselves in the historical context of sex and\/or gender categories. Gender is largely socially constructed,\u00a0however, it\u00a0the form it takes is\u00a0shaped and influenced by biological sex\u00a0(American Psychological Association, 2015).\u00a0So, what does it mean to be a boy or a man? What does it mean to be a girl or a woman?\r\n\r\nFirst let\u2019s start with the basics. \u201cBoy\/man\u201d, and \u201cgirl\/woman\u201d are indeed gender categories that most people identify with. Historically, the categories have been tied to the perceived biological\u00a0sex of the individual, with \u201cboy\/man\u201d correlating to biological males and\r\n\u201cgirl\/woman\u201d correlating to biological females. A person is \u201ccisgender\u201d when their gender identity matches their assigned sex (i.e., identifies as a woman and was assigned female at birth). A person is \u201ctransgender\u201d when their gender identity does not match their assigned sex.\u00a0(American Psychological Association, 2015).\u00a0A person is \u201cnon-binary\u201d when they\u00a0don\u2019t identify as either a \u201cboy\/man\u201d or \u201cgirl\/woman\u201d. Non-binary people may or may not also identify as transgender, this will vary from person to person.\r\n\r\nIn many cultures, gender categories are constructed with the presumption people\u2019s gender identity maps easily onto their (assumed) biological sex. However, there is a lot more to being a man or woman then whether a person has a penis or a vagina and breasts. For instance, masculinity and femininity play a huge role in many people\u2019s conception of their own gender. For most of history, society has been organized by a binary system, male or female, starting with birth certificates. At the moment\u00a0of birth, every infant is labelled either male or female by a medical authority, and this is usually registered with the government (Preves, 2002).\u00a0From here, parents and other adults begin to place expectations on who the infant will be as they grow, for instance, what kind of toys they will like or their favorite colour. Because adults start treating the child as a person with gender based on the biological sex before the child has developed their own sense of gender identity, the infant\u2019s own sense of gender reacts and responds to these expectations. Masculinity and femininity\u00a0is\u00a0the expression of\u00a0these reactions and responses.\u00a0The decision to shave facial hair or not could be considered an expression of masculinity. The decision to wear make-up or not could be considered an expression of femininity. It is not that choosing to wear make-up, or grow out one\u2019s beard makes one more masculine or feminine, so much as the choice is an expression of how one relates to these categories on their own terms. Many women wear make-up, many choose not to. Many men can\u2019t help but grow out long beards, many simply can\u2019t grow one at all\u00a0(Schippers, 2007).\r\n\r\nIt would be wrong to suggest that biological sex doesn\u2019t have any influence over gender. Our minds, thoughts, feelings and identities are ultimately generated by the brain and body. For instance, testosterone is a hormone responsible for behaviors and traits associated with social domination and certain types of aggression,\u00a0such as risk-assessment, initiative and task performance (Goudriaan\u00a0et al.,\u00a02010; Platje\u00a0et al.,\u00a02015; Welling et al., 2016).\u00a0For many\u00a0species,\u00a0biological\u00a0males\u00a0experience\u00a0an increase in testosterone production\u00a0during puberty, often leading to an increase in muscle mass and body hair and reduction in body fat. Despite popular conception however, this doesn\u2019t make testosterone the \u201cboy\/male\u201d hormone since\u00a0<em>both\u00a0<\/em>males and females have\u00a0measurable\u00a0levels of testosterone. While it is true that males\u00a0produce more testosterone, it\u2019s inaccurate to say that testosterone plays no role in\u00a0female physiology, meaning that testosterone is part of what shapes\u00a0girls\u00a0too. Secondly,\u00a0it\u2019s\u00a0entirely possible that a cisgender boy may go through puberty and not display any increase in the behaviors associated with testosterone at any point in his life. This doesn\u2019t mean this boy has any less testosterone in his system than his peers (Booth et al., 2006).\u00a0 And even if that were the case, that wouldn\u2019t somehow invalidate the boy\u2019s identity as a \u201cboy\u201d experiencing a \u201cboy\u2019s puberty.\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/section>\r\n<h4>Intersex Conditions<\/h4>\r\nChromosomal, gonadal, and genital sex most commonly follow either a route to a male reproductive system which donates X and Y gametes via sperm or an XX female system that provides an environment for conception and growth of a fertilized egg. However genetic sex and gonadal sex do not always follow this typical pattern, for example there are\u00a0XY\u00a0individuals with\u00a0vaginas.\u00a0The external genitals derive from the same tissue so they commonly develop along a continuum with male-typical at one end and female-typical at the other, though some individuals are born with genitals that fall somewhere in the middle of this range. The term\u00a0<strong>intersex<\/strong>\u00a0refers to individuals who have characteristics that do not fit typical male and female categories.\u00a0 Intersex is an umbrella term to describe many variations, which are sometimes referred to as disorders of sexual development. Since intersex conditions are not harmful to health and usually only affect reproduction, the term disorder to describe these individuals is not accurate.\r\n\r\nChromosomes and gonads are not easy to see, so\u00a0often\u00a0the appearance of the external genitals is used to determine sex at birth.\u00a0However, as mentioned above, this\u00a0practice has historically led to the misclassification of intersex\u00a0people. In fact, this can have a number of consequences for the person in question, including a misunderstanding of their own bodies health, and difficulties navigating the medical system.\u00a0Rates of intersexuality within the human population are difficult to ascertain, especially considering the history of unethical medical intervention on intersex infants. There have been unfortunately many cases of doctors performing unnecessary corrective surgery in order to make the genitals of an intersex infant more \u201cnormal\u201d. Occasionally, the parents of the infant may not have been informed of the condition or procedure, nor given their consent. While this is justified as being done to provide the infant with a more normal life, most intersex advocacy groups are strongly opposed to this practice.\u00a0Often a person has no reason to suspect they are intersex until they reach puberty and, in some cases, it\u2019s only discovered\u00a0after the death of the individual.\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nFor more information on intersex conditions, check out the FAQ for\u00a0interACT, an advocacy group for intersex youth:\u00a0<a href=\"https:\/\/interactadvocates.org\/faq\/\" target=\"_blank\" rel=\"noopener\">https:\/\/interactadvocates.org\/faq\/<\/a>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/section><\/header><\/div>\r\n<h3>Prenatal Influences<\/h3>\r\nThe placenta\u00a0is a structure that develops during pregnancy and\u00a0provides nourishment and oxygen to the fetus. Almost everything the pregnant parent ingests, including food\u202fand\u202fmedication, travels through the placenta to the fetus,\u00a0hence the phrase \u201ceating for two.\u201d In fact, the parental\u202fenvironment\u00a0can have long-term effects on the developing fetus.\u00a0A\u202fteratogen\u202fis any environmental agent\u2014biological, chemical, or physical\u2014that causes damage to the developing embryo or fetus.\u00a0Most\u00a0teratogens have their greatest impact during early pregnancy.\u202fTake for example, lead, which can cause lead poisoning if the pregnant parent becomes\u202fexposed\u00a0from\u202fsources like paint or soil.\u202fSince the ban on\u00a0leaded\u00a0gasoline in the early 90\u2019s, levels in children has declined dramatically,\u202fyet\u202fchildhood lead poisoning remains a global health concern. Research shows that even extremely low levels of lead exposure can\u202fstill have\u202fnegative effects, including cognitive\u202fimpairments\u202f(Koller\u202fet al., 2004). In the United States alone, deaths related to lead poising are comparable to those caused by smoking tobacco, around 412,000 a year (O\u2019Connor et al., 2020).\r\n\r\nMany recreational\u202fdrugs,\u202flike\u00a0alcohol and tobacco\u202fare considered teratogens\u202fbecause\u00a0they can\u202fcross the placenta and\u00a0negatively\u00a0affect the fetus.\u202fOther teratogens include\u202fexposure to\u202fradiation and\u202fviruses such\u202fas HIV,\u202fherpes, and rubella (German measles). \u202fAdditionally, people who experience high stress during pregnancy are more likely to have children with enhanced responses to stress (Leung et al., 2010).\r\n\r\n<section id=\"fs-idm38503568\">\u00a0<\/section><strong><a id=\"TTprenataldev\"><\/a>TRICKY TOPIC: PRENATAL DEVELOPMENT<\/strong>\r\n\r\n[embed]https:\/\/youtu.be\/vN2NRvyQ6Dc[\/embed]\r\n\r\n<em>If the video above does not load, click here:\u00a0<a href=\"https:\/\/youtu.be\/vN2NRvyQ6Dc\">https:\/\/youtu.be\/vN2NRvyQ6Dc<\/a><\/em>\r\n<em>For a full transcript of this video, click <a href=\"\/intropsychneuro\/back-matter\/appendix\/#prenataldev\">here<\/a><\/em>\r\n<h3 class=\"os-title\"><span style=\"font-size: 1em\">Infancy Through Childhood<\/span><\/h3>\r\n<\/section><section id=\"fs-idp16156640\">\r\n<p id=\"fs-idp84575904\">The average newborn weighs approximately 7.5 pounds. \u202fAlthough small, a newborn is not completely helpless because\u202ftheir\u202freflexes and sensory capacities help\u202fthem\u202finteract with the environment from the moment of birth. All healthy babies are born with\u202fnewborn reflexes: inborn automatic responses to\u202fspecific\u202fforms of stimulation. Reflexes help the newborn survive until\u202fthey're\u202fcapable of more complex\u202fbehaviours\u2014these reflexes are crucial to survival. They are present in babies whose brains are developing normally and usually disappear around 4\u20135 months old. Let\u2019s\u202ftake a look\u202fat some of these newborn reflexes.<\/p>\r\nThe rooting reflex is the newborn\u2019s response to anything that touches their cheek: When you stroke a baby\u2019s cheek, they naturally\u202fturn\u202ftheir head in that direction and begin to suck. The sucking reflex is the automatic, unlearned, sucking motions that infants do with their mouths.\u202fYou can observe the grasping reflex\u202fif you put your finger into a newborn\u2019s hand,\u202fthey\u202fautomatically\u202fgrasp\u202fanything that touches their palms. The Moro reflex is the newborn\u2019s response when a baby feels like they are falling. The baby spreads their arms, pulls them back in, and then (usually) cries. How do you think these reflexes promote survival in the first months of life?\r\n<div id=\"fs-idm31186432\" class=\"psychology link-to-learning ui-has-child-title\"><section>\r\n<div class=\"os-note-body\">\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">Take a few minutes to view this brief\u00a0<a href=\"http:\/\/openstax.org\/l\/newflexes\" target=\"_blank\" rel=\"noopener nofollow\">video clip about newborn reflexes<\/a>\u00a0to learn more.<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/section><\/div>\r\nWhat can young infants see, hear, and smell? Newborn infants\u2019 sensory abilities are significant, but their senses are not yet fully developed. Many of a newborn\u2019s innate preferences facilitate interaction with caregivers and other humans. Although vision is their least developed sense, newborns already show a preference for faces. Babies who are just a few days old also prefer human voices, they will listen to voices longer than sounds that do not involve speech (Vouloumanos\u202f&amp;\u202fWerker, 2004), and they seem to prefer the voice of the\u202fparent who was pregnant\u202fover a stranger\u2019s voice (Mills &amp;\u202fMelhuish, 1974). In an interesting experiment, 3-week-old babies were given pacifiers\u202fthat played a recording\u202fof the\u202fpregnant\u00a0parent\u2019s voice\u202fand of a stranger\u2019s voice. When the infants heard their parent\u2019s voice, they sucked more strongly at the pacifier (Mills &amp;\u202fMelhuish, 1974). Newborns also have a strong sense of smell. For instance, newborn babies can distinguish the smell of the\u202fparent who was pregnant\u202ffrom that of others. In a study by MacFarlane (1978), 1-week-old babies who were being breastfed were placed between two gauze pads. One gauze pad was from the bra of a nursing parent who was a stranger, and the other gauze pad was from the bra of the infant\u2019s own nursing parent. More than two-thirds of the week-old babies turned toward the gauze pad with their own nursing parent\u2019s scent.\r\n\r\n<section id=\"fs-idm70473856\">\r\n<h4>Physical Development<\/h4>\r\nDuring infancy, toddlerhood, and early childhood, the body\u2019s physical development is rapid.\u202fOn average,\u00a0newborns weigh between 5 and 10 pounds.\u202fBy 2 years old, this weight will have quadrupled,\u00a0with\u00a0most 2 year\u202folds\u202fweighing between 20 and 40 pounds (WHO\u202fMulticentre\u202fGrowth Reference Study Group, 2006).\u202f Growth slows between 4 and 6 years old. During this time children gain 5\u20137 pounds and grow about 2\u20133 inches per year.\r\n\r\nThere are two important patterns of development: <strong>cephalocaudal<\/strong> and\u202f<strong>proximodistal<\/strong>. Cephalocaudal development refers to the pattern of growth from the head down, also referred to\u00a0as development from head to toe.\u202fProximodistal\u202fdevelopment is the tendency for growth to start in the\u202fcentre\u202fof the body and move outwards to the extremities. This is reflected in the development of more general motor skills of the limbs close to the torso before development of fine motor skills in the fingers and toes.\r\n<div id=\"Figure_09_04_Growth\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"975\"]<img id=\"79062\" src=\"https:\/\/openstax.org\/resources\/4ad318b49b3059f225d0464d1044dfb3925d79e9\" alt=\"A collage of four photographs depicting babies is shown. From left to right they get progressively older. The far left photograph is a bundled up sleeping newborn. To the right is a picture of a toddler next to a toy giraffe. To the right is a baby blowing out a single candle. To the far right is a child on a swing set.\" width=\"975\" height=\"244\" \/> Figure LD.10\u00a0Children experience rapid physical changes through infancy and early childhood. (credit \"left\": modification of work by Kerry Ceszyk; credit \"middle-left\": modification of work by Kristi Fausel; credit \"middle-right\": modification of work by \"devinf\"\/Flickr; credit \"right\": modification of work by Rose Spielman)[\/caption]<\/figure>\r\n<\/div>\r\nThe\u202fnervous system continues to grow and develop\u202fafter\u202fbirth;\u202feach neural pathway forms thousands of new connections during infancy and toddlerhood. This period of rapid neural growth is called blooming. The blooming period of neural growth is then followed by a period of pruning, where neural connections are reduced. It is thought that pruning\u202fallows\u202fthe brain to function more efficiently, allowing for mastery of more complex skills (Hutchinson, 2011). Blooming occurs during the first few years of\u00a0life, and\u00a0pruning continues through childhood and into adolescence in various areas of the brain.\r\n<p id=\"fs-idm2425248\">The size of our brains increases rapidly. For example, the brain of a 2-year-old is 55% of its adult size, and by 6 years old the brain is about 90% of its adult size (Tanner, 1978). During early childhood (ages 3\u20136), the frontal lobes grow rapidly.\u202fThe frontal lobes are associated with planning, reasoning, memory, and impulse control. Therefore, by the time children reach school age, they are developmentally capable of controlling their attention and\u202fbehaviour.\u00a0Through\u00a0the elementary\u00a0school years, the frontal, temporal, occipital, and parietal lobes all\u202fgrow in size. The brain growth spurts experienced in childhood tend to follow Piaget\u2019s sequence of cognitive development, so that significant changes in neural functioning are associated with\u202fcognitive advances (Kolb &amp;\u202fWhishaw, 2009; Overman,\u202fBachevalier, Turner, &amp;\u202fPeuster, 1992).<\/p>\r\nMotor development occurs in an orderly sequence as infants move from reflexive reactions (e.g., sucking and rooting) to more advanced motor functioning.\u202fMotor skills\u202frefer to our ability to move our bodies and manipulate objects.\u202fFine motor skills\u202ffocus on the muscles in our fingers, toes, and eyes, and enable coordination of small actions (e.g., grasping a toy, writing with a pencil, and using a spoon).\u202fGross motor skills\u202ffocus on large muscle groups that control our arms and legs and involve larger movements (e.g., balancing, running, and jumping).\r\n\r\nAs motor skills develop, there are certain developmental milestones that young children\u202ftypically\u202fachieve\u202fat certain age ranges\u202f(<a href=\"https:\/\/interactadvocates.org\/faq\/#Table_09_03_02\" target=\"_blank\" rel=\"noopener\">Table LD.4<\/a>)\u00a0An example of a developmental milestone is sitting. On average, most babies sit alone at 7 months old. Sitting involves both coordination and muscle strength, and 90% of babies achieve this milestone between 5 and 9 months old. \u202fIn another example, babies on average\u202fare able to\u202fhold up their head at 6 weeks old, and 90% of babies achieve this between 3 weeks and 4 months old.\u00a0If\u202fa\u202fchild is displaying delays on several milestones, that\u202fcould be\u202freason for concern\u202fsince some\u202fdevelopmental delays can be identified and addressed through early intervention.\r\n<div id=\"Table_09_03_02\" class=\"os-table\">\r\n<table class=\"top-titled\" style=\"height: 189px\" summary=\"Table 9.4 \">\r\n<thead>\r\n<tr style=\"height: 14px\">\r\n<th style=\"height: 14px;width: 899.062px\" colspan=\"5\" scope=\"col\">Table LD.4 Developmental Milestones, Ages 2\u20135 Years<\/th>\r\n<\/tr>\r\n<tr style=\"height: 29px\">\r\n<th style=\"height: 29px;width: 46.0625px\" scope=\"col\">Age (years)<\/th>\r\n<th style=\"height: 29px;width: 128.062px\" scope=\"col\">Physical<\/th>\r\n<th style=\"height: 29px;width: 195.062px\" scope=\"col\">Personal\/Social<\/th>\r\n<th style=\"height: 29px;width: 241.062px\" scope=\"col\">Language<\/th>\r\n<th style=\"height: 29px;width: 233.062px\" scope=\"col\">Cognitive<\/th>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr style=\"height: 29px\" valign=\"top\">\r\n<td style=\"height: 29px;width: 46.0625px\">2<\/td>\r\n<td style=\"height: 29px;width: 128.062px\">Kicks a ball; walks up and down stairs<\/td>\r\n<td style=\"height: 29px;width: 195.062px\">Plays alongside other children; copies adults<\/td>\r\n<td style=\"height: 29px;width: 241.062px\">Points to objects when named; puts 2\u20134 words together in a sentence<\/td>\r\n<td style=\"height: 29px;width: 233.062px\">Sorts shapes and colours; follows 2-step instructions<\/td>\r\n<\/tr>\r\n<tr style=\"height: 29px\" valign=\"top\">\r\n<td style=\"height: 29px;width: 46.0625px\">3<\/td>\r\n<td style=\"height: 29px;width: 128.062px\">Climbs and runs; pedals tricycle<\/td>\r\n<td style=\"height: 29px;width: 195.062px\">Takes turns; expresses many emotions; dresses self<\/td>\r\n<td style=\"height: 29px;width: 241.062px\">Names familiar things; uses pronouns<\/td>\r\n<td style=\"height: 29px;width: 233.062px\">Plays make believe; works toys with parts (levers, handles)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 44px\" valign=\"top\">\r\n<td style=\"height: 44px;width: 46.0625px\">4<\/td>\r\n<td style=\"height: 44px;width: 128.062px\">Catches balls; uses scissors<\/td>\r\n<td style=\"height: 44px;width: 195.062px\">Prefers social play to solo play; knows likes and interests<\/td>\r\n<td style=\"height: 44px;width: 241.062px\">Knows songs and rhymes by memory<\/td>\r\n<td style=\"height: 44px;width: 233.062px\">Names colours and numbers; begins writing letters<\/td>\r\n<\/tr>\r\n<tr style=\"height: 44px\" valign=\"top\">\r\n<td style=\"height: 44px;width: 46.0625px\">5<\/td>\r\n<td style=\"height: 44px;width: 128.062px\">Hops and swings; uses fork and spoon<\/td>\r\n<td style=\"height: 44px;width: 195.062px\">Distinguishes real from pretend; likes to please friends<\/td>\r\n<td style=\"height: 44px;width: 241.062px\">Speaks clearly; uses full sentences<\/td>\r\n<td style=\"height: 44px;width: 233.062px\">Counts to 10 or higher; prints some letters and copies basic shapes<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1em;font-style: italic;font-weight: bold\">Cognitive Development<\/span><\/div>\r\n<\/div>\r\n<\/section><section id=\"fs-idm68003168\">\r\n<p id=\"fs-idm83412368\">In addition to rapid physical growth, young children also exhibit significant development of their cognitive abilities. Piaget thought that children\u2019s ability to understand objects\u2014such as learning that a rattle makes a noise when shaken\u2014was a cognitive skill that develops slowly as a child matures and interacts with the environment. Today, developmental psychologists think Piaget was incorrect. Researchers have found that even very young children understand\u202fphysical properties of\u202fobjects long before they have\u202fdirect\u202fexperience with those objects (Baillargeon, 1987;\u202fBaillargeon, Li,\u202fGertner, &amp; Wu, 2011). For example, children as young as 3 months old demonstrated knowledge of the properties of objects that they had only viewed and did not have prior experience with them. In one study, 3-month-old infants were shown a truck rolling down a track and behind a screen. The box, which appeared solid but was\u202factually hollow, was placed next to the track. The truck rolled past the box as would be expected. Then the box was placed on the track to block the path of the truck. When the truck was rolled down the track this time, it continued unimpeded. The infants spent significantly more time looking at this impossible event (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_04_TruckBox\" target=\"_blank\" rel=\"noopener\">Figure LD.11<\/a>).\u202fBaillargeon\u202f(1987) concluded that they knew solid objects cannot pass through each other.\u202fBaillargeon\u2019s\u202ffindings suggest that very young children\u202fhave an understanding of\u202fobjects and how they work, which Piaget (1954) would have said is beyond their cognitive abilities due to their limited experiences in the world.<\/p>\r\n\r\n<div id=\"Figure_09_04_TruckBox\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"975\"]<img id=\"1415\" src=\"https:\/\/openstax.org\/resources\/4718c3bc0c5ee7b8424ca343b2d257e97ecf31ef\" alt=\"Image A shows a toy truck coasting along a track unobstructed. Image B shows a toy truck coasting along a track with a box in the background. Image C shows a truck coasting along a track and going through what appears to be an obstruction.\" width=\"975\" height=\"188\" \/> Figure LD.11\u00a0In Baillargeon\u2019s study, infants observed a truck (a) roll down an unobstructed track, (b) roll down an unobstructed track with an obstruction (box) beside it, and (c) roll down and pass through what appeared to be an obstruction.[\/caption]<\/figure>\r\n<div class=\"os-caption-container\">\r\n\r\nLike physical milestones, there are also cognitive milestones\u202fchildren typically reach at certain ages. For example, infants shake their head \u201cno\u201d around 6\u20139 months, and they respond to verbal requests to do things like \u201cwave bye-bye\u201d or \u201cblow a kiss\u201d around 9\u201312 months. Remember Piaget\u2019s ideas about object permanence? \u202fWe can expect children to grasp the concept that objects continue to exist even when they are not in sight by around 8 months old. Because toddlers (i.e., 12\u201324 months old) have mastered\u00a0object permanence,\u00a0they enjoy games\u00a0like hide and seek, and they realize that when someone leaves the room they will come back (Loop, 2013). Toddlers also point to pictures in books and look in appropriate places when you ask them to find objects.\r\n\r\n<\/div>\r\n<\/div>\r\nPreschool-age children (i.e., 3\u20135 years old) also make steady progress in cognitive development. Not only can they count, name\u202fcolours, and tell you their name and age, but they can also make some decisions on their own, such as choosing an outfit to wear. Preschool-age children understand basic time concepts and sequencing (e.g., before and after), and they can predict what will happen next in a story. They also begin to enjoy the use of\u00a0humour\u00a0in stories. Because they can think symbolically, they enjoy pretend\u00a0play\u00a0and\u00a0inventing\u00a0elaborate characters and scenarios. One of the most common examples of their cognitive growth is their blossoming curiosity. Preschool-age children love to ask \u201cWhy?\u201d\r\n\r\nAn important cognitive change occurs in children this age. Recall that Piaget described 2\u20133 year\u00a0olds\u00a0as egocentric, meaning that they do not have an awareness of others\u2019 points of view. Between 3 and 5 years old, children come to understand that people have thoughts, feelings, and beliefs that are different from their own. This is known as theory-of-mind (TOM). Children can use this skill to tease others, persuade their parents to purchase a candy bar, or understand why a sibling might be angry. When children develop TOM, they can recognize that others have false beliefs (Dennett, 1987; Callaghan et al., 2005).\r\n<div id=\"fs-idp31181840\" class=\"psychology link-to-learning ui-has-child-title\"><section>\r\n<div class=\"os-note-body\">\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">False-belief tasks are useful in determining a child\u2019s acquisition of theory-of-mind (TOM). Take a look at this\u00a0<a href=\"http:\/\/openstax.org\/l\/crayons\" target=\"_blank\" rel=\"noopener nofollow\">video clip that shows a false belief task involving a box of crayons<\/a>\u00a0to learn more.<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/section><\/div>\r\nCognitive skills continue to expand in middle and late childhood (6\u201311 years old). Thought processes become more logical and organized when dealing with concrete information (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_04_Game\" target=\"_blank\" rel=\"noopener\">Figure LD.12<\/a>). Children at this age understand concepts such as the past, present, and future, giving them the ability to plan and work toward goals. Additionally, they can process complex ideas such as addition and subtraction and cause-and-effect relationships.\r\n<div id=\"Figure_09_04_Game\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"325\"]<img id=\"85680\" src=\"https:\/\/openstax.org\/resources\/79444ed5208262b28fcaeca69235ae3c0b56ef71\" alt=\"A photograph of children playing baseball is shown. Five children are in the picture, two on one team, and three on the other.\" width=\"325\" height=\"215\" \/> Figure LD.12\u00a0Because they understand luck and fairness, children in middle and late childhood (6\u201311 years old) are able to follow rules for games. (credit: Edwin Martinez)[\/caption]<\/figure>\r\n<\/div>\r\nOne well-researched aspect of cognitive development is language acquisition.\u202fThe order in which children learn language structures is consistent across children and cultures (Hatch, 1983).\u202fStarting before birth, babies begin to develop language and communication skills. At birth, babies apparently recognize the voice of their birth parent, and can discriminate between the language(s) spoken by their\u202fbirth parent\u202fand foreign languages, and they show preferences for faces that are moving in synchrony with audible language (Blossom &amp; Morgan, 2006; Pickens, 1994;\u202fSpelke\u202f&amp; Cortelyou, 1981).\r\n\r\nChildren communicate information through gesturing long before they speak, and there is some evidence that gesture usage predicts subsequent language development (Iverson &amp; Goldin-Meadow, 2005). In terms of producing spoken language, babies begin to\u00a0coo\u00a0almost immediately. Cooing is a one-syllable combination of a consonant and a vowel sound (e.g., coo or\u202fba). Interestingly, babies replicate sounds from their own languages. A baby whose parents speak French will coo in a different tone than a baby whose parents speak Spanish or Urdu. After cooing, the baby starts to babble. Babbling begins with repeating a syllable, such as\u00a0ma-ma, da-da, or\u202fba-ba. When a baby is about 12 months old, we expect them to say their first word for meaning, and to start combining words for meaning at about 18 months.\r\n\r\nAt about 2 years old, a toddler uses between 50 and 200 words; by 3 years old they have a vocabulary of up to 1,000 words and can speak in sentences. During the early childhood years, children's vocabulary increases at a rapid pace. This is sometimes referred to as the \u201cvocabulary spurt\u201d and has been claimed to involve an expansion in vocabulary at a rate of 10\u201320 new words per week. Recent research may indicate that while some children experience these spurts, it is far from universal (as discussed in Ganger &amp; Brent, 2004). It has been estimated\u00a0that,\u00a05 year\u00a0olds\u00a0understand about 6,000 words, speak 2,000 words, and can define words and question their meanings. They can rhyme and name the days of the week. Seven year\u00a0olds\u00a0speak fluently and use slang and clich\u00e9s (Stork &amp;\u202fWiddowson, 1974).\r\n\r\nWhat accounts for such dramatic language learning by children? Behaviorist B. F. Skinner thought that we learn language in response to reinforcement or feedback, such as through parental approval or\u202fsimply by\u202fbeing understood. For example, when a two-year-old child asks for juice, they might say, \u201cme juice,\u201d to which their parent might respond by giving them a cup of apple juice. Noam Chomsky (1957) criticized Skinner\u2019s theory and proposed that we are all\u00a0born with an innate capacity to learn language. Chomsky called this mechanism a language acquisition device (LAD). Researchers now believe that language acquisition is partially inborn and partially learned through our interactions with our linguistic environment (Gleitman\u202f&amp; Newport, 1995; Stork &amp;\u202fWiddowson, 1974).\r\n\r\n<\/section><section id=\"fs-idm42075248\">\r\n<h4>Attachment<\/h4>\r\nPsychosocial development occurs as children form relationships, interact with others, and understand and manage their feelings. In social and emotional development, forming healthy attachments is very important and is the major social milestone of infancy.\u202fAttachment\u202fis a long-standing connection or bond with others\u202fand is often used to describe the emotional bond between child and caregiver. Attachment is more easily established during the early years of a child's life and is therefore thought to be reflective of a sensitive period. Developmental psychologists are interested in how infants reach this milestone. They ask such questions as: How do parent and infant attachment bonds form? How does neglect affect these bonds? What accounts for children\u2019s attachment differences?\r\n\r\nResearchers Harry Harlow, John Bowlby, and Mary Ainsworth conducted studies designed to answer these questions. In the 1950s, Harlow conducted a series of experiments on monkeys. He separated newborn monkeys from their mothers. Each monkey was presented with two surrogate mothers. One surrogate monkey was\u00a0made out of\u00a0wire mesh, and dispensed\u202fmilk. The other monkey was softer and made from cloth: This monkey did not dispense milk. Research shows that the monkeys preferred the soft, cuddly cloth monkey, even though it did not provide any nourishment. The baby monkeys spent their time clinging to the cloth monkey and only went to the wire monkey when they needed to be fed. Prior to this study, the medical and scientific communities generally thought that babies become attached to the people who provide their nourishment.\u202fHowever, Harlow (1958) concluded that there was more to the\u202fbirth parent-child bond than nourishment. Feelings of comfort and security are the\u202fcritical components to parental-infant bonding, which leads to healthy psychosocial development.\r\n<div id=\"fs-idp31454704\" class=\"psychology link-to-learning ui-has-child-title\"><section>\r\n<div class=\"os-note-body\">\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">Harlow\u2019s studies of monkeys were performed before modern ethics guidelines were in place, and today his experiments are widely considered to be unethical and even cruel. Watch this\u00a0<a href=\"http:\/\/openstax.org\/l\/monkeystudy\" target=\"_blank\" rel=\"noopener nofollow\">video of actual footage of Harlow's monkey studies<\/a>\u00a0to learn more.<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/section><\/div>\r\nBuilding on the work of Harlow and others, John Bowlby developed the concept of attachment theory. He defined attachment as the affectional bond that\u202fan\u202finfant forms\u202fwith the parent who birthed them\u202f(Bowlby, 1969). An infant must form this bond with a primary caregiver in order to have normal social and emotional development. In addition, Bowlby proposed that this attachment bond is very powerful and continues throughout life. He used the concept of secure base to define a healthy attachment between parent and child (1988). A\u202fsecure base\u202fis a parental presence that gives the child a sense of safety as he explores his surroundings. Bowlby said that two things are needed for a healthy attachment: The caregiver must be responsive to the child\u2019s physical, social, and emotional needs; and the caregiver and child must engage in mutually enjoyable interactions (Bowlby, 1969) (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_04_BabySmile\" target=\"_blank\" rel=\"noopener\">Figure LD.13<\/a>).\r\n<div id=\"Figure_09_04_BabySmile\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"487\"]<img id=\"32769\" src=\"https:\/\/openstax.org\/resources\/b264621e863ce1b7a80d3858e981efbecdf548c2\" alt=\"A man holds a baby in the air.\" width=\"487\" height=\"334\" \/> Figure LD.13\u00a0Mutually enjoyable interactions promote the parent-infant bond. (credit: \"balouriarajesh_Pixabay\"\/Pixabay)[\/caption]<\/figure>\r\n<div class=\"os-caption-container\">\r\n\r\nWhile Bowlby thought attachment was an all-or-nothing process, Mary Ainsworth\u2019s (1970) research showed otherwise. Ainsworth wanted to know if children differ in the ways they bond, and if so, why. To find the answers, she used the Strange Situation procedure to study attachment between\u00a0parents\u00a0and their infants (1970).\u202fIn the Strange Situation, the\u202fprimary caregiver and\u00a0child\u00a0(age 12-18 months) are placed in a room together. There are toys in the room, and the caregiver and child spend some time alone in the room. After the child has had time to explore their surroundings, a stranger enters the room. The caregiver then leaves the baby with the stranger. After a few minutes, the caregiver returns to comfort their child.\r\n\r\n<\/div>\r\n<\/div>\r\n<p id=\"fs-idp113719280\">Based on how the infants\/toddlers responded to the separation and reunion, Ainsworth identified three types of parent-child attachments: secure, avoidant, and resistant (Ainsworth &amp; Bell, 1970). A fourth style, known as disorganized attachment, was later described (Main &amp; Solomon, 1990). The most common type of attachment\u202fis called\u202fsecure attachment\u202f(<a href=\"https:\/\/youtu.be\/vN2NRvyQ6Dc#Figure_09_04_Secure\" target=\"_blank\" rel=\"noopener\">Figure LD.14<\/a>). In this type of attachment, the toddler prefers their parent over a stranger. The attachment figure is used as a secure base to explore the environment and is sought out in times of stress. Securely attached children were distressed when their caregivers left the room in the Strange Situation experiment, but when their caregivers returned, the securely attached children were happy to see them. Securely attached children have caregivers who are sensitive and responsive to their needs.<\/p>\r\n\r\n<div id=\"Figure_09_04_Secure\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"488\"]<img id=\"97859\" src=\"https:\/\/openstax.org\/resources\/1fb890e1e5af46b6e33a2799a1f5e85fac3f1f51\" alt=\"A photograph shows a person squatting down next to a small child who is standing up.\" width=\"488\" height=\"365\" \/> Figure LD.14\u00a0In secure attachment, the parent provides a secure base for the toddler, allowing them to securely explore his environment. (credit: Kerry Ceszyk)[\/caption]<\/figure>\r\n<div class=\"os-caption-container\">\r\n\r\nWith\u202favoidant attachment, the child is unresponsive to the parent, does not use the parent as a secure base, and does not\u202fappear\u202fto\u00a0care if the parent leaves. The toddler reacts to the parent the same way they react to a stranger. When the parent does return, the child is slow to show a positive reaction. Ainsworth theorized that these children were most likely to have a caregiver who was inattentive to their needs (Ainsworth,\u202fBlehar, Waters, &amp; Wall, 1978).\r\n\r\n<\/div>\r\n<\/div>\r\nIn cases of\u202fresistant attachment, children tend to show clingy\u202fbehaviour, but then they reject the attachment figure\u2019s attempts to interact with them (Ainsworth &amp; Bell, 1970). These children do not explore the toys in the room, as they are too fearful. During separation in the Strange Situation, they became extremely disturbed and angry with the parent. When the parent returns, the children are difficult to comfort. Resistant attachment is the result of the caregivers\u2019 inconsistent level of response to their child.\r\n\r\nFinally, children with\u202fdisorganized attachment\u202fbehaved oddly in the Strange Situation. They freeze, run around the room in an erratic manner, or try to run away when the caregiver returns (Main &amp; Solomon, 1990). This type of attachment is seen most often in kids who have been abused. Research has shown that abuse disrupts a child\u2019s ability to regulate their emotions.\r\n\r\nWhile Ainsworth\u2019s research has found support in subsequent studies, it has also met criticism. Some researchers have pointed out that a child\u2019s temperament may have a strong influence on attachment (Gervai, 2009; Harris, 2009), and others have noted that attachment varies from culture to culture, a factor not accounted for in Ainsworth\u2019s research (Rothbaum, Weisz, Pott, Miyake, &amp; Morelli, 2000; van\u202fIjzendoorn\u202f&amp;\u202fSagi-Schwartz, 2008).\r\n<div id=\"fs-idm1064944\" class=\"psychology link-to-learning ui-has-child-title\"><section>\r\n<div class=\"os-note-body\">\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">Watch this\u00a0<a href=\"http:\/\/openstax.org\/l\/strangesitu\" target=\"_blank\" rel=\"noopener nofollow\">video clip of the Strange Situation<\/a>\u00a0and try to identify which type of attachment baby Lisa exhibits.<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/section><\/div>\r\n<\/section><section id=\"fs-idm42031072\">\r\n<h4>Self-Concept<\/h4>\r\nJust as attachment is the main psychosocial milestone of infancy, the primary psychosocial milestone of childhood is the development of a positive sense of self. How does self-awareness develop?\u202fIf you place a baby in front of a mirror, they will reach out to touch their image, thinking it is another baby. However, by about 18 months a toddler will recognize that the person in the mirror is them. How do we know this? In a well-known experiment, a researcher placed a red dot of paint on children\u2019s noses before putting them in front of a mirror (Amsterdam, 1972). Commonly known as the mirror test, this\u202fbehaviour\u202fis demonstrated by humans and a few other species and is considered evidence of self-recognition (Archer, 1992). At 18 months\u202fold\u202fthey would touch their own noses when they saw the paint, surprised to see a spot on their faces. By 24\u201336 months old children can name and\/or point to themselves in pictures, clearly indicating self-recognition.\r\n\r\nChildren from 2\u20134 years old display a great increase in social\u202fbehaviour\u202fonce they have established a self-concept. They enjoy playing with other children, but they have difficulty sharing their possessions.\u202fAlso, through play children explore and come to explore gender roles (Chick,\u202fHeilman-Houser, &amp; Hunter, 2002).\u202fBy 4 years old, children can cooperate with other children, share when asked, and separate from parents with little anxiety. Children at this age also exhibit autonomy, initiate tasks, and carry out plans. Success in these areas contributes to a positive sense of self. Once children reach 6 years old, they can identify themselves in terms of group memberships: \u201cI\u2019m a first grader!\u201d School-age children compare themselves to their peers and discover that they are competent in some areas and less so in others (recall Erikson\u2019s task of industry versus inferiority). At this age, children recognize their own personality traits as well as some other traits they would like to have. For example, 10-year-old\u202fAlix\u202fsays, \u201cI\u2019m kind of shy. I wish I could be more talkative like my friend Ro.\u201d\r\n\r\nDevelopment of a positive self-concept is important to healthy development. Children with a positive self-concept tend to be more confident, do better in school, act more independently, and are more willing to try new activities (Maccoby, 1980; Ferrer &amp; Fugate, 2003). Formation of a positive self-concept begins in Erikson\u2019s toddlerhood stage, when children establish autonomy and become confident in their abilities. Development of self-concept continues in elementary school, when children compare themselves to others. When the comparison is\u202ffavourable, children feel a sense of competence and are motivated to work harder and accomplish more. Self-concept is re-evaluated in Erikson\u2019s adolescence stage, as teens form an identity. They\u00a0internalize the messages they have received regarding their strengths and weaknesses, keeping some messages and rejecting others. Adolescents who have achieved identity formation\u00a0are capable of contributing\u00a0positively to society (Erikson, 1968).\r\n<div id=\"zip-idm242576096\" class=\"psychology dig-deeper ui-has-child-title\"><section>\r\n<div><\/div>\r\n<div class=\"os-note-body\"><span style=\"text-align: initial;font-size: 1em\">One behavioural aspect that contributes to children\u2019s developing sense of self-identity is play. Children spend a significant portion of their day playing,\u202fpre-schoolers\u202foften\u00a0spending\u202fmost\u202fof the day engaged in some sort of play activity (Malloy, 2020). Play is an important aspect of social and cognitive development as it makes social learning something children desire to engage in. Play also provides the space for children to begin practicing social skills such as\u202fhumour, which has been found to have influence on peer acceptance and perceived social competence. It has even been argued that play is an essential element in the acquisition of language and concept meaning.\u202fGiven this, it seems reasonable to assume that the interest children take in play and\u00a0developmental concepts like self-concept, motivation, learning and security in relationships (Lillemyr\u202fet al., 2010).\u202f\u00a0<\/span><\/div>\r\n<\/section><\/div>\r\n<\/section>Children develop a personal sense of play style at as young as the second year\u00a0to\u00a0life. It\u2019s at this stage we see children start to make choices of individuation, such as toy preference. Toy preference is one of the earliest places we begin to see children develop a sense of gender identity,\u202fone study\u202fshowed\u202fgender-based toy preferences at as young as 12-months old (Servin,\u00a0Bohlin, and Berlin, 1999). One might expect that children would show a preferential bias towards toys assigned to the same sex-category as the biological sex of the child, with\u00a0AFAB\u00a0children showing a higher preference for \u201cgirls\u2019 toys\u201d and AMAB children showing a higher preference for \u201cboys\u2019 toys\u201d. However, the full story is more complex. Parents and authority figures begin instilling children with gender norms based on their own cultural expectations of gender from the moment the child is born. (van\u202fde\u00a0Beek\u00a0et al., 2006). Because of this, it is possible that children\u2019s expressions of self may be influenced by the expectation that there is a correct way for them to perform self-hood. It\u00a0also\u00a0worth keeping in mind that many studies looking at expressions of gender mistakenly use a circular definition in the construction of their categories. A circular definition is a definition that uses one or more of the terms being defined as part of its definition. For instance, it would be circular to claim that violent video\u00a0game\u00a0cause teenagers to be violent because violent teenagers play violent video games.\r\n\r\nTake for instance a study which attempted to measure the rate at which infants preferred toys assigned to the same gender category assigned to the infant\u202f(Alexander et al, 2009). To do this, they tracked rates at which infants visually fixated on one of two toys; a doll (the \u201cgirls\u2019 toy\u201d) or a truck (the \u201cboys\u2019 toy\u201d)\u202fand\u202fcompared the amount of time\u202fAFAB and AMAB\u202fchildren spent fixated on each toy. The published study claims to have found notable discrepancies in gender-based toy preference. However, there are two major issues. First, the study uses a circular definition in constructing its\u202ftoy\u202fcategories. The researchers designated the doll a \u201cgirls\u2019 toy\u201d as it was the toy preferred by girls based on the presumption that girls prefer them. The second problem with this study is that their results do not support their claim.\u202fBased on average\u202fvisual fixating on each object, AFAB infants preferred the doll to the truck.\u202f AFAB infants spent approximately the same amount of time fixated on the truck as AMAB infants, and AMAB infants\u202factually spent\u202fslightly longer looking\u202fat\u202fthe doll than the truck (though\u202fthis difference was quite small).\u202fThis\u202funderscores the importance of critically evaluating published\u202fscientific\u202fstudies to\u202fso as to\u202fnot mistakenly believe false or misinterpreted conclusions.\r\n\r\nSo, what can\u202fwe conclude about children\u2019s early\u202ftoy preferences and play style? Generally, there are two perspectives on childhood development, one based\u00a0in\u00a0the social environment of the child, and one based more in biology.\u202fThe social environment perspective posits that children\u2019s preferences are influenced by parents and authority figures (such as teachers) who can reinforce or discourage a child\u2019s preferences. The biological perspective claims that children\u2019s preferences are\u202finfluenced\u202fby\u202fgonadal\u202fhormones,\u202flike testosterone\u202f(Servin,\u00a0Bohlin, and Berlin, 1999),\u202fwhich is associated with\u202fpreference for stereotypically masculine toys\u202fand\u202fphysically active \u201crough and tumble\u201d play (van de\u00a0Beek\u00a0et al., 2006).\u202fBoth the social environment and the presence of hormones\u202fare associated with\u202fchildren\u2019s\u202ftoy\u202fpreferences,\u202fplay-style, and self-concept (Servin,\u00a0Bohlin, and Berlin, 1999; Chick et al, 2002).\r\n<div id=\"fs-idp15890800\" class=\"psychology everyday-connection ui-has-child-title\"><section>\r\n<div class=\"os-note-body\">\r\n<div class=\"textbox textbox--examples\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">EVERYDAY CONNECTION<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<h4 id=\"83781\" class=\"os-subtitle\"><span class=\"os-subtitle-label\">The Importance of Play and Recess<\/span><\/h4>\r\nAccording to the American Academy of Pediatrics (2007), unstructured play is an integral part of a child\u2019s development. It builds creativity, problem solving skills, and social relationships. Play also allows children to develop a theory-of-mind as they imaginatively take on the perspective of others.\r\n\r\nOutdoor play allows children the opportunity to directly experience and sense the world around them. While doing so, they may collect objects that they come across and develop lifelong interests and hobbies. They also benefit from increased\u00a0exercise and\u00a0engaging in outdoor play can\u00a0actually increase\u00a0how much they enjoy physical activity. This helps support the development of a healthy heart and brain.\u202fResearch suggests that today\u2019s children are engaging in less and less outdoor play (Clements, 2004).\u202fWhile it is true that easier access to calorie-dense food has led to an increase in levels of childhood obesity, this alone does not explain the decrease in physical activity. There are\u00a0actually a\u00a0number of factors that may contribute to this decrease in physical activity. Easier access to calorie-dense foods have contributed to increased levels of childhood obesity. It has also become more difficult for children to both access the space required for physical activity and feel safe doing so. Due to parental concerns about things like road safety and stranger danger, children these days have low levels of independent mobility (ie. freedom to travel outdoors without adult supervision). This means that children frequently lack the opportunity to play outdoors. Additionally, factors such as playground\u00a0overcrowding\u00a0and the presence of teenagers\/older children\u00a0has\u00a0been shown to decrease physical activity in children. Play spaces designed to encourage structured activities like team sports may not appeal to all children, many of whom are shown to be more physically active when engaged in activities like creating things or using their imaginations. It has also been shown that children who cross perceived gender norms are likely to be the targets of bullying and\/or disapproval from their peers and elders. Due to the gender stereotypes associated with different forms of physical activity, it seems likely that some children may choose to not engage in a physical activity to avoid harassment (inversely, some may choose to participate in an activity solely to avoid the same harassment) (Reimers\u202fet al., 2018).\r\n\r\nDespite the adverse consequences associated with reduced play, some children are over scheduled and have little free time to engage in unstructured play. In addition, some schools have taken away recess time for children in a push for students to do better on standardized tests, and many schools commonly use loss of recess as a form of punishment. Do you agree with these practices? Why or why not?\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/section><\/div>\r\n<\/section><section id=\"fs-idm9670032\">\r\n<h3>Adolescence<\/h3>\r\n<p id=\"fs-idp31435184\">Adolescence is a socially constructed concept. In pre-industrial society, children were considered adults when they reached physical maturity, but today we have an extended time between childhood and adulthood called adolescence.\u202fAdolescence\u202fis the period of development that begins at puberty and ends at emerging adulthood, which is discussed later. In the United States, adolescence is seen as a time to develop independence from parents while remaining connected to them (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_04_Adolescent\" target=\"_blank\" rel=\"noopener\">Figure LD.15<\/a>). The typical age range of adolescence is from 12 to 18 years, and this stage of development also has some predictable physical, cognitive, and psychosocial milestones.<\/p>\r\n\r\n<div id=\"Figure_09_04_Adolescent\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"325\"]<img id=\"72952\" src=\"https:\/\/openstax.org\/resources\/0b823efdca083be0d94ab78e28f2efa6672be364\" alt=\"A photograph captures four people midair as they hold hands and jump.\" width=\"325\" height=\"168\" \/> Figure LD.15\u00a0Peers are a primary influence on our development in adolescence. (credit: \"manseok_Pixabay\"\/ Pixabay)[\/caption]<\/figure>\r\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1em;font-style: italic;font-weight: bold\">Physical Development<\/span><\/div>\r\n<\/div>\r\n<section id=\"fs-idm75846112\">As noted above, adolescence begins with puberty. While the sequence of physical changes in puberty is predictable, the onset and pace of puberty vary widely. Several physical changes occur during puberty, such as\u202fadrenarche\u202fand\u202fgonadarche, the maturing of the adrenal glands and sex glands, respectively.\u00a0Also\u00a0during this time, primary and secondary sexual characteristics develop and mature.\u202fPrimary sexual characteristics\u202fare organs specifically needed for reproduction, like the uterus, ovaries, and testes.\u202fSecondary sexual characteristics\u202fare physical signs of sexual maturation that do not directly involve sex organs, such as\u202fdevelopment of breasts and hips,\u202fdevelopment of facial hair and a deepened voice.\u202fAround half of children will\u202fexperience\u202fmenarche, the beginning of menstrual periods, usually around 12\u201313 years old. The other half\u202fwill\u202fexperience\u202fspermarche, the first ejaculation, around 13\u201314 years old. Sexual development is triggered by an increase in secretion of hormones\u202feither from the ovaries or\u202fthe testes.\r\n\r\nDuring puberty,\u202fmost people\u202fexperience a rapid increase in height (i.e., growth spurt). For those going through\u00a0an estrogen-dominated puberty, this\u202fbegins between 8 and 13 years old, with adult height reached between 10 and 16 years old.\u202fThose going through\u00a0a testosterone-dominated\u202fpuberty\u202fbegin their growth spurt slightly later, usually between 10 and 16 years old, and reach their adult height between 13 and 17 years old.\u202fBoth nature (i.e., genes) and nurture (e.g., nutrition, medications, and medical conditions) can influence height.\r\n<p id=\"fs-idm78910480\">Because rates of physical development vary so widely among teenagers, puberty can be a source of pride or embarrassment. Early maturing males tend to be stronger, taller, and more athletic than their later maturing peers. They are usually more popular, confident, and independent, but they are also at a greater risk for substance abuse and early sexual activity (Flannery, Rowe, &amp; Gulley, 1993; Kaltiala-Heino, Rimpela, Rissanen, &amp; Rantanen, 2001). Early maturing females may be teased or overtly admired, which can cause them to feel self-conscious about their developing bodies. These females are at a higher risk for depression, substance abuse, and eating disorders (Ge, Conger, &amp; Elder, 2001; Graber, Lewinsohn, Seeley, &amp; Brooks-Gunn, 1997; Striegel-Moore &amp; Cachelin, 1999). Late blooming males and females (i.e., they develop more slowly than their peers) may feel self-conscious about their lack of physical development. Negative feelings are particularly a problem for late maturing males, who are at a higher risk for depression and conflict with parents (Graber et al., 1997) and more likely to be bullied (Pollack &amp; Shuster, 2000).<\/p>\r\n<p id=\"fs-idp52884496\">The adolescent brain also remains under development. Up until puberty, brain cells continue to bloom in the frontal region. Adolescents engage in increased risk-taking\u202fbehaviours\u202fand emotional\u00a0outbursts\u00a0possibly because the frontal lobes of their brains are still developing (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_04_TeenBrain\" target=\"_blank\" rel=\"noopener\">Figure LD.16<\/a>). Recall that this area is responsible for judgment, impulse control, and planning, and it is still maturing into early adulthood (Casey,\u202fTottenham, Liston, &amp;\u202fDurston, 2005).<\/p>\r\n\r\n<div id=\"Figure_09_04_TeenBrain\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"487\"]<img id=\"78201\" src=\"https:\/\/openstax.org\/resources\/1aefd4ccc54684d8afae35da46828327e4a182f5\" alt=\"An illustration of a brain is shown with the frontal lobe labeled.\" width=\"487\" height=\"362\" \/> Figure LD.16\u00a0Brain growth continues into the early 20s. The development of the frontal lobe, in particular, is important during this stage.[\/caption]<\/figure>\r\n<\/div>\r\n<div id=\"fs-idp97645824\" class=\"psychology link-to-learning ui-has-child-title\"><section>\r\n<div class=\"os-note-body\">\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">According to neuroscientist Jay Giedd in the Frontline video \u201cInside the Teenage Brain\u201d (2013), \u201cIt\u2019s sort of unfair to expect [teens] to have adult levels of organizational skills or decision-making before their brains are finished being built.\u201d Watch this segment on\u00a0<a href=\"http:\/\/openstax.org\/l\/wiringbrain\" target=\"_blank\" rel=\"noopener nofollow\">\u201cThe Wiring of the Adolescent Brain\u201d<\/a>\u00a0to find out more about the developing brain during adolescence.<\/div>\r\n<\/div>\r\n<\/div>\r\n<strong><a id=\"TTmyeprecor\"><\/a>TRICKY TOPIC: MYELINATION OF THE PREFRONTAL CORTEX\r\n<\/strong>\r\n\r\n[embed]https:\/\/youtu.be\/DHljv1t2_uk[\/embed]\r\n\r\n<em>If the video above does not load, click here:\u00a0<a href=\"https:\/\/youtu.be\/DHljv1t2_uk\">https:\/\/youtu.be\/DHljv1t2_uk<\/a><\/em>\r\n<em>For a full transcript of this video, click <a href=\"\/intropsychneuro\/back-matter\/appendix\/#myeprecor\">here<\/a><\/em>\r\n\r\n<\/section><\/div>\r\n<\/section><section id=\"fs-idp64913392\">\r\n<h4>Cognitive Development<\/h4>\r\nMore complex thinking abilities emerge during adolescence. Some researchers suggest this is due to increases in processing speed and efficiency rather than as the result of an increase in mental capacity\u2014in other words, due to improvements in existing skills rather than development of new ones (Bjorkland, 1987; Case, 1985). During adolescence, teenagers move beyond concrete thinking and become capable of abstract thought. Recall that Piaget refers to this stage as formal operational thought. Teen thinking is also characterized by the ability to consider multiple points of view, imagine hypothetical situations, debate ideas and opinions (e.g., politics, religion, and justice), and form new ideas (<a href=\"http:\/\/openstax.org\/l\/monkeystudy#Figure_09_04_Reasoning\" target=\"_blank\" rel=\"noopener\">Figure LD.17<\/a>). In addition, it\u2019s not uncommon for adolescents to question authority or challenge established societal norms.\r\n<p id=\"fs-idm18304048\">Cognitive empathy, also known as theory-of-mind (which we discussed earlier\u00a0with regard to\u00a0egocentrism), relates to the ability to take the perspective of others and feel concern for others\u00a0(Shamay-Tsoory,\u202fTomer, &amp;\u202fAharon-Peretz, 2005). Cognitive empathy begins to increase in adolescence and is an important component of social problem solving and conflict avoidance.<\/p>\r\n\r\n<div id=\"Figure_09_04_Reasoning\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"325\"]<img id=\"90931\" src=\"https:\/\/openstax.org\/resources\/d469b961542c10b3cb934657648deb27d55c5e38\" alt=\"A picture shows four people gathered around a table attempting to figure out a problem together.\" width=\"325\" height=\"217\" \/> Figure LD.17\u00a0Teenage thinking is characterized by the ability to reason logically and solve hypothetical problems such as how to design, plan, and build a structure. (credit: U.S. Army RDECOM)[\/caption]<\/figure>\r\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1em;font-style: italic;font-weight: bold\">Psychosocial Development<\/span><\/div>\r\n<\/div>\r\n<\/section><section id=\"fs-idm2098944\">Adolescents continue to refine their sense of self as they relate to others. Erikson referred to the task of the adolescent as one of identity versus role confusion. Thus, in Erikson\u2019s view, an adolescent\u2019s main questions are \u201cWho am I?\u201d and \u201cWho do I want to be?\u201d Some adolescents adopt the values and roles that their parents expect for them. Other teens develop identities that are in opposition to their parents but align with a peer group. This is common as peer relationships become a central focus in adolescents\u2019 lives.\r\n\r\nAs adolescents work to form their identities, they pull away from their parents, and the peer group becomes very important (Shanahan, McHale, Osgood, &amp;\u202fCrouter, 2007). Despite spending less time with their parents, most teens report positive feelings toward them (Moore, Guzman, Hair,\u202fLippman, &amp; Garrett, 2004). Warm and healthy parent-child relationships have been associated with positive child outcomes, such as better grades and fewer school\u202fbehaviour\u202fproblems, in the United States as well as in other countries (Hair et al., 2005).\r\n\r\nIt appears that most teens don\u2019t experience adolescent\u00a0storm\u00a0and stress to the degree once famously suggested by G. Stanley Hall, a pioneer in the study of adolescent development. Only small numbers of teens have major conflicts with their parents (Steinberg &amp; Morris, 2001), and most disagreements are minor. For example, in a study of over 1,800 parents of adolescents from various cultural and ethnic groups, Barber (1994) found that conflicts occurred over day-to-day issues such as homework, money, curfews, clothing, chores, and friends. These types of arguments tend to decrease as teens develop (Galambos\u202f&amp; Almeida, 1992). There is emerging research on the adolescent brain. Galvan, Hare, Voss, Glover and Casey (2007) examined its role in risk-taking\u202fbehaviour. They used fMRI to assess the readings\u2019 relationship to risk-taking, risk perception, and impulsivity. The researchers found that there was no correlation between brain activity in the neural reward\u202fcentre\u202fand impulsivity and risk perception. However, activity in that part of the brain was correlated to risk taking. In other words, risk-taking adolescents experienced brain activity in the reward\u202fcentre. The idea that adolescents, however, are\u202fbut\u202fmore\u00a0impulsive than other demographics was challenged in their research, which included children and adults.\r\n\r\n<\/section><\/section><section id=\"fs-idp16033584\"><section id=\"fs-idp7178272\">\r\n<div id=\"zip-idm245833632\" class=\"psychology link-to-learning ui-has-child-title\"><section>\r\n<div class=\"os-note-body\">\r\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">DIG DEEPER<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<h4>Developmental Trajectories among Indigenous populations in Canada:\u00a0The Impact of the Indian Residential School System<\/h4>\r\nChildhood and adolescence are life stages pivotal to someone\u2019s developmental maturation (Cabral &amp; Patel, 2020; Cassidy &amp; Shaver, 2018; White et al., 2017). Experiences such as adversity, loss, trauma, and\/or maltreatment have been linked to feelings of anxiety and depression (Hovens et al., 2015; Jurena et al., 2020) as well as issues with attachment in older adult relationships (Cohen et al., 2012; Lo et al., 2017), issues in development (Sege et al., 2017), and other health problems (Asselmann et al., 2018; Nelson et al., 2020; Rojo-Wissar et al., 2021).\r\n\r\nSince confederation (1867), the Canadian federal government has continued to forcefully attempt total assimilation of Indigenous peoples into \u201cEuro-Canadian culture and society\u201d (Truth and Reconciliation Commission [TRC], 2015). One of the ways in which the government has attempted to do this was through the Indian Residential School (IRS) system (TRC, 2015). The IRS system in Canada has often been referred to as a series of concentration camps (TRC, 2015) or \u201cboarding schools\u201dused to house Indigenous children. Unlawful and immoral acts perpetuated in the IRSs have been termed \"cultural genocide\" at the international level (TRC, 2015; United Nations Declaration on the Rights of Indigenous Peoples [UNDRIP], 2007).\r\n<h5>Impact on Attachment<\/h5>\r\nFrom 1876 until the last school closed in 1996, the Canadian federal government physically forced hundreds of thousands of Indigenous children (as young as 4-years-old from their homes and communities, into IRSs (TRC, 2015). Indigenous parents, caregivers and\/or family members who showed verbal or physical restraint relative to the police-enforced taking of Indigenous children to IRSs, were often jailed or shot and killed (Bombay et al., 2014ab; Facing History and Ourselves, 2021; TRC, 2015). Once Indigenous children arrived at the schools, many children were stripped, shaved, and had their skin dyed lighter by IRS staff (Smith, n.d.; TRC, 2015). Students were then assigned numbers (used by staff in place of birth names), were separated from their siblings, and told that if they spoke their Indigenous language (the only language most children knew), there would be severe consequences (TRC, 2015). While it is expected that temporary separations from loved ones (e.g., parents) under tense conditions increased the risk of health issues later in life (R\u00e4ikk\u00f6nen et al., 2011), extended separations under tense conditions are expected to have increased Survivor risk of depressive symptoms and\/or disorders (Bohman et al., 2017; Coffino, 2009) and anxiety symptoms and\/or disorders (Bryant et al., 2017; L\u00e4hdepuro et al., 2019).\r\n<h5>Intergenerational Impacts<\/h5>\r\nFederal, institutional and academic inquiries into the IRS system continue to highlight various atrocities experienced by many IRS Survivors such as spiritual, verbal, emotional, physical and sexual assault, abuse and violence (TRC, 2015). Trauma of this magnitude continues to impact not only the Survivors, but their children, grandchildren, and other relatives (Bombay et al., 2014ab). This phenomenon, known as <strong>intergenerational trauma<\/strong>, has direct and indirect impacts on various generations of Indigenous populations (Bombay et al., 2014ab; Lehrner &amp; Yehuda, 2018). For example, Indigenous children of IRS Survivors are more likely to have poor psychological health because of the IRS impacts on their parents\u2019 psychosocial functioning and health (Bombay et al., 2011; 2014ab; 2018; Elias et al., 2012; Kaspar, 2014).\r\n<h5>Biopsychosocial Framework<\/h5>\r\nIn general, a Biopsychosocial Framework has been characterised by the ways biological, psychological, and social factors can affect an individual and helps health practitioners conceptualize manifestation of particular physical or mental health issues (Karunamuni et al., 2020). With this framework, it is not hard to understand that while many IRSs delivered\/had poor curriculum, instruction, staffing, and high levels of racism (Barnes &amp; Josefowitz, 2019; TRC, 2015), many Survivors were academically ill-equipped (e.g., lacked adequate language proficiency; Barnes et al., 2006) and oftentimes extremely poorly prepared for adult employment (Miller, 1996; TRC, 2015). It is expected that the cumulative trauma experienced at the IRSs lead to many Survivors struggling with psychosocial well-being\/regulation, connection with other Indigenous socio cultural customs, practices and peoples, and physical and mental health difficulties (Barnes et al., 2019; Ogle et al., 2013; Miller, 1996; TRC, 2015; Vachon et al., 2015).\r\n<h5>Cumulative Risk<\/h5>\r\nCumulative risk can be understood as the number and severity of adversities (e.g., low SES, addict parent or caregiver) experienced in childhood, wherein a greater number and severity of adversities often \u201cadds\u201d to a greater risk of an individual to experience later physical and mental health issues (Boles, 2021; Kwong &amp; Hayes, 2017; Felitti &amp; Anda, 2009; Felitti et al., 1998). Putting this research into context, IRS Survivors who underwent separation from parents, and experienced abuse, racism, and forced immersion in a hostile non-Indigenous culture, were all factors that had a cumulative impact and amplified adverse effects of their adverse experiences at IRS (McQuaid et al., 2017; Richmond et al., 2009). As many Indigenous peoples were directly or indirectly affected by IRSs and colonization, in combination with deficient health resources\/geographical isolation, and other ongoing inequities, it is not surprising that many health inequities faced by Indigenous peoples documented 20 years ago, are still faced today (Gracey &amp; King, 2009; RCAP, 1996; TRC, 2015).\r\n<h5>Cultural Resilience<\/h5>\r\nWhile Indigenous peoples in Canada continue to face premeditated colonial assimilation tactics, such as the child welfare crisis or \"modern day IRS system\" (Ma et al., 2019; McMillan, 2021; Mitchell, 2019), resilience among Indigenous populations in Canada continues to be researched (Bombay et al., 2010; 2011; Paul et al., 2022). To date, various facets of cultural identity among Indigenous populations in Canada have shown to be protective of the negative effects of colonization, such as cultural community belonging (Bombay et al., 2014ab; First Nations Health Authority, 2019; Paul et al., 2022). While Indigenous culture has been suggested to be protective and stabilize and\/or heighten various aspects of health and wellbeing (e.g., Paul et al., 2022), continued research is needed to better understand how these cultural facets can be implemented in culturally-appropriate care models for Indigenous populations.\r\n\r\nTo learn more about Indian Residential Schools, visit:\u00a0<a href=\"https:\/\/www.youtube.com\/watch?v=2zuRQmwaREY\">https:\/\/www.youtube.com\/watch?v=2zuRQmwaREY<\/a>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/section><\/div>\r\n<\/section><\/section>","rendered":"<div class=\"PageContent-ny9bj0-0 iapMdy\">\n<div id=\"main-content\" class=\"MainContent__HideOutline-sc-6yy1if-0 bdVAq\">\n<div id=\"aa700c98-2a9e-4bb8-b838-6cb4f461d12a\">\n<div id=\"80731\" class=\"ui-has-child-title\">\n<section>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">Learning Objectives<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>By the end of this section, you will be able to:<\/p>\n<ul>\n<li>Describe the stages of prenatal development<\/li>\n<li>Identify factors that influence prenatal development<\/li>\n<li>Explain theories of cognitive and psychosocial development<\/li>\n<li>Describe the major changes that occur in adolescence<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/section>\n<\/div>\n<p id=\"fs-idp10820480\">Development\u202ffrom conception into a\u00a0fully grown\u00a0human involves\u202fmajor\u202falterations\u202fto anatomy, physiology,\u202fcognition, and\u202fbehaviour, and many of these\u202fchanges follow a\u202fpredictable,\u202fage-based\u202fprogression.\u202fThis\u202fsection will\u202fdiscuss prenatal, infant, child, adolescent, and adult development\u202facross three domains: physical, cognitive, and psychosocial.<\/p>\n<section id=\"fs-idm56322048\">\n<h3>Prenatal Development<\/h3>\n<p>How did you come to be who you are? From beginning as a one-cell structure to\u00a0your\u00a0birth, your\u202fprenatal development\u202foccurred in an orderly and delicate sequence.\u202fThere are three\u202fmain\u202fstages of prenatal development: germinal, embryonic, and fetal.\u202fLet\u2019s\u202fexplore\u202fwhat happens to the developing baby in each of these stages.<\/p>\n<section id=\"fs-idp18677712\">\n<h4>Germinal Stage (Conception\u2013Week 2)<\/h4>\n<p>Each biological parent\u202fcontributes\u202fDNA\u202fat the moment\u202fof conception,\u202fwhen sperm\u202fand\u202fegg\u202funite to\u202fform a\u202fsingle-celled\u202fzygote (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-2-lifespan-theories#Figure_09_02_Conception\" target=\"_blank\" rel=\"noopener\">Figure LD.7<\/a>).\u202fGrowth and development of the zygote\u202fare\u202fguided by\u202fthese inherited\u202fgenetic instructions, coded in DNA within\u00a046 chromosomes, 23 from each parent.\u202fIn mammals, sex is determined by contribution of specific chromosomes, females are typically XX and males are typically XY, so it\u2019s the\u00a0male parent\u2019s\u00a0contribution that determines genetic sex, a female parent only has\u00a0Xs\u00a0to contribute.<\/p>\n<figure id=\"attachment_2228\" aria-describedby=\"caption-attachment-2228\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2228 size-large\" src=\"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-content\/uploads\/sites\/21\/2020\/06\/LD7-1024x388.png\" alt=\"Side by side photos. Left photo shows microscope image of sperm fusing with ovum. Right image shows 23 pairs of chromosomes in an array.\" width=\"1024\" height=\"388\" srcset=\"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-content\/uploads\/sites\/21\/2020\/06\/LD7-1024x388.png 1024w, https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-content\/uploads\/sites\/21\/2020\/06\/LD7-300x114.png 300w, https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-content\/uploads\/sites\/21\/2020\/06\/LD7-768x291.png 768w, https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-content\/uploads\/sites\/21\/2020\/06\/LD7-65x25.png 65w, https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-content\/uploads\/sites\/21\/2020\/06\/LD7-225x85.png 225w, https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-content\/uploads\/sites\/21\/2020\/06\/LD7-350x133.png 350w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><figcaption id=\"caption-attachment-2228\" class=\"wp-caption-text\">Figure LD.7 (a) Sperm and ovum fuse at the point of\u202fconception. (b) 23 pairs of human chromosomes inherited from each parent, box displays the sex chromosomes; one large X and a smaller Y in this individual.<\/figcaption><\/figure>\n<figure><\/figure>\n<div id=\"Figure_09_02_Conception\" class=\"os-figure\">\n<div>During the first week after conception, the zygote divides and multiplies, going from a one-cell structure to two cells, then four cells, then eight cells, and so on. This process of cell division is called\u202fmitosis. Mitosis is a fragile process, and fewer than one-half of all zygotes survive beyond the first two weeks (Hall, 2004). After 5 days of mitosis there are 100 cells, and after 9 months there are billions of cells. As the cells divide, they become more specialized, forming different organs and body parts. In the germinal stage, the mass of cells\u00a0has\u00a0yet to attach itself to the lining of\u202fthe\u202futerus. Once it does, the next stage begins.<\/div>\n<div><\/div>\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1em;font-style: italic;font-weight: bold\">Embryonic Stage (Weeks 2\u20138)<\/span><\/div>\n<\/div>\n<\/section>\n<section id=\"fs-idp59294704\">After the zygote divides for about 7\u201310 days and has 150 cells, it travels down the fallopian tubes and implants itself in the lining of the uterus. Upon implantation, this multi-cellular organism is called an\u202fembryo.\u202fBlood vessels grow, forming the placenta,\u202fa structure connected to the uterus that provides nourishment and oxygen\u202fto the developing embryo via the umbilical cord. Basic structures of the embryo start to develop into areas that will become the head, chest, and abdomen. During the embryonic stage, organs form and begin to function, at this stage there is a detectable\u202fheart-beat. The neural tube forms along the back of the embryo, developing into the spinal cord and brain.<\/section>\n<section id=\"fs-idp44106368\">\n<h4>Fetal Stage (Week 8-9 &#8211; Onward)<\/h4>\n<p id=\"fs-idp100731664\"><span style=\"text-align: initial;font-size: 1em\">At\u00a0about nine weeks, the embryo\u202fbecomes\u202fa fetus. At this stage, the fetus is about the size of a\u00a0kidney bean and begins to take on the recognizable form of a human being.\u00a0It&#8217;s during the fetal stage that the sex organs begin to differentiate. At about 16 weeks, the fetus is approximately\u00a04.5 inches\u00a0long. Fingers and toes are fully developed, and fingerprints are visible. By the time the fetus reaches the sixth month of development (24 weeks), it weighs up to\u00a01.4 pounds.\u00a0Hearing has developed, so the fetus can respond to sounds. The internal organs, such as the lungs, heart, stomach, and intestines, have formed enough that a fetus born prematurely at this point has a chance to survive outside of\u202fthe\u202fwomb. Throughout the fetal stage the brain continues to grow and develop, nearly doubling in size from weeks 16 to 28. Around 36 weeks, the fetus is almost ready for birth. It weighs about 6 pounds and is about 18.5 inches long, and by week 37\u202fall of\u202fthe fetus\u2019s organ systems are developed enough that it could survive outside the uterus without many of the risks associated with premature birth. The fetus continues to gain weight and grow in length until approximately 40 weeks. By then, the fetus has very little room to move\u202faround\u202fand birth becomes imminent. The progression through the stages is\u00a0shown\u202fin\u00a0<\/span><a class=\"autogenerated-content\" style=\"text-align: initial;font-size: 1em\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_02_Stages\">Figure LD.8<\/a><span style=\"text-align: initial;font-size: 1em\">.<\/span><\/p>\n<div id=\"Figure_09_02_Stages\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 731px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"38919\" src=\"https:\/\/openstax.org\/resources\/1752bba5757c2d2e2f43fb7a6d4a3baf7abfd135\" alt=\"The growth of a fetus is shown using nine pictures in different stages of development. For each stage, there is a picture of a fetus which gets progressively larger and more mature. The first stage is labeled \u201c9 weeks; fetal stage begins.\u201d The second stage is labeled \u201c12 weeks; sex organs differentiate.\u201d The third stage is labeled \u201c16 weeks; fingers and toes develop.\u201d The fourth stage is labeled \u201c20 weeks; hearing begins.\u201d The fifth stage is labeled \u201c24 weeks; lungs begin to develop.\u201d The sixth stage is labeled \u201c28 weeks; brain grows rapidly.\u201d The seventh stage is labeled \u201c32 weeks; bones fully develop.\u201d The eighth stage is labeled \u201c36 weeks; muscles fully develop.\u201d The ninth stage is labeled \u201c40 weeks; full-term development.\u201d\" width=\"731\" height=\"763\" \/><figcaption class=\"wp-caption-text\">Figure LD.8\u00a0During the fetal stage, the baby&#8217;s brain develops and the body adds size and weight, until the fetus reaches full-term development.<\/figcaption><\/figure>\n<\/figure>\n<\/div>\n<\/section>\n<\/section>\n<\/div>\n<\/div>\n<\/div>\n<section id=\"fs-idm38503568\">\n<div id=\"fs-idm27510448\" class=\"psychology what-do-you-think ui-has-child-title\">\n<header>\n<h4><em>Reproductive Development and Sex Assignment<\/em><\/h4>\n<section>\n<p id=\"fs-idp65129824\">The first step in differentiation of the reproductive organs happens with a sexless collection of cells at an area called the germinal ridge. In mammals, the main determinant of the pathway the germinal ridge follows is the SRY gene on the Y chromosome. This gene leads to the growth and specialization of cells in the inner portion of the germinal ridge, which eventually become the testes. In the absence of this gene, as in XX individuals, the outer part of the germinal ridge develops into ovaries. Both the testes and ovaries are\u00a0<strong>gonads<\/strong>, reproductive organs that contain reproductive hormones and gametes (sperm or eggs). In most XY individuals, high levels of fetal androgens, like testosterone, released from the testes promote development of the external\u00a0<strong>genitals<\/strong>\u00a0into a penis. In the absence of testosterone, as in most XX individuals, this same tissue becomes a vagina.\u00a0The practice of sexing newborn infants in this way has historically led misclassification of intersex people. Therefore, the terms\u00a0<em>assigned female at birth<\/em>\u00a0(<strong>AFAB)<\/strong>\u00a0and\u00a0<em>assigned male at birth<\/em>\u00a0(<strong>AMAB<\/strong>) describe biological sex more accurately than female and male, since it includes intersex individuals. This terminology is preferred by many members of transgender, intersex and non-binary communities since it acknowledges an individual\u2019s medical history and allows a distinction between biological sex and gender identity.<\/p>\n<div id=\"Figure_09_02_Prenatal\" class=\"os-figure\"><\/div>\n<div id=\"zip-idm242576096\" class=\"psychology dig-deeper ui-has-child-title\">\n<section>\n<div class=\"os-note-body\">\n<div class=\"textbox textbox--exercises\"><\/div>\n<\/div>\n<\/section>\n<\/div>\n<\/section>\n<\/header>\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">DIG DEEPER<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<h4>Understanding Gender<\/h4>\n<p>Gender refers to the way in which one perceives themselves in the historical context of sex and\/or gender categories. Gender is largely socially constructed,\u00a0however, it\u00a0the form it takes is\u00a0shaped and influenced by biological sex\u00a0(American Psychological Association, 2015).\u00a0So, what does it mean to be a boy or a man? What does it mean to be a girl or a woman?<\/p>\n<p>First let\u2019s start with the basics. \u201cBoy\/man\u201d, and \u201cgirl\/woman\u201d are indeed gender categories that most people identify with. Historically, the categories have been tied to the perceived biological\u00a0sex of the individual, with \u201cboy\/man\u201d correlating to biological males and<br \/>\n\u201cgirl\/woman\u201d correlating to biological females. A person is \u201ccisgender\u201d when their gender identity matches their assigned sex (i.e., identifies as a woman and was assigned female at birth). A person is \u201ctransgender\u201d when their gender identity does not match their assigned sex.\u00a0(American Psychological Association, 2015).\u00a0A person is \u201cnon-binary\u201d when they\u00a0don\u2019t identify as either a \u201cboy\/man\u201d or \u201cgirl\/woman\u201d. Non-binary people may or may not also identify as transgender, this will vary from person to person.<\/p>\n<p>In many cultures, gender categories are constructed with the presumption people\u2019s gender identity maps easily onto their (assumed) biological sex. However, there is a lot more to being a man or woman then whether a person has a penis or a vagina and breasts. For instance, masculinity and femininity play a huge role in many people\u2019s conception of their own gender. For most of history, society has been organized by a binary system, male or female, starting with birth certificates. At the moment\u00a0of birth, every infant is labelled either male or female by a medical authority, and this is usually registered with the government (Preves, 2002).\u00a0From here, parents and other adults begin to place expectations on who the infant will be as they grow, for instance, what kind of toys they will like or their favorite colour. Because adults start treating the child as a person with gender based on the biological sex before the child has developed their own sense of gender identity, the infant\u2019s own sense of gender reacts and responds to these expectations. Masculinity and femininity\u00a0is\u00a0the expression of\u00a0these reactions and responses.\u00a0The decision to shave facial hair or not could be considered an expression of masculinity. The decision to wear make-up or not could be considered an expression of femininity. It is not that choosing to wear make-up, or grow out one\u2019s beard makes one more masculine or feminine, so much as the choice is an expression of how one relates to these categories on their own terms. Many women wear make-up, many choose not to. Many men can\u2019t help but grow out long beards, many simply can\u2019t grow one at all\u00a0(Schippers, 2007).<\/p>\n<p>It would be wrong to suggest that biological sex doesn\u2019t have any influence over gender. Our minds, thoughts, feelings and identities are ultimately generated by the brain and body. For instance, testosterone is a hormone responsible for behaviors and traits associated with social domination and certain types of aggression,\u00a0such as risk-assessment, initiative and task performance (Goudriaan\u00a0et al.,\u00a02010; Platje\u00a0et al.,\u00a02015; Welling et al., 2016).\u00a0For many\u00a0species,\u00a0biological\u00a0males\u00a0experience\u00a0an increase in testosterone production\u00a0during puberty, often leading to an increase in muscle mass and body hair and reduction in body fat. Despite popular conception however, this doesn\u2019t make testosterone the \u201cboy\/male\u201d hormone since\u00a0<em>both\u00a0<\/em>males and females have\u00a0measurable\u00a0levels of testosterone. While it is true that males\u00a0produce more testosterone, it\u2019s inaccurate to say that testosterone plays no role in\u00a0female physiology, meaning that testosterone is part of what shapes\u00a0girls\u00a0too. Secondly,\u00a0it\u2019s\u00a0entirely possible that a cisgender boy may go through puberty and not display any increase in the behaviors associated with testosterone at any point in his life. This doesn\u2019t mean this boy has any less testosterone in his system than his peers (Booth et al., 2006).\u00a0 And even if that were the case, that wouldn\u2019t somehow invalidate the boy\u2019s identity as a \u201cboy\u201d experiencing a \u201cboy\u2019s puberty.<\/p>\n<\/div>\n<\/div>\n<\/section>\n<h4>Intersex Conditions<\/h4>\n<p>Chromosomal, gonadal, and genital sex most commonly follow either a route to a male reproductive system which donates X and Y gametes via sperm or an XX female system that provides an environment for conception and growth of a fertilized egg. However genetic sex and gonadal sex do not always follow this typical pattern, for example there are\u00a0XY\u00a0individuals with\u00a0vaginas.\u00a0The external genitals derive from the same tissue so they commonly develop along a continuum with male-typical at one end and female-typical at the other, though some individuals are born with genitals that fall somewhere in the middle of this range. The term\u00a0<strong>intersex<\/strong>\u00a0refers to individuals who have characteristics that do not fit typical male and female categories.\u00a0 Intersex is an umbrella term to describe many variations, which are sometimes referred to as disorders of sexual development. Since intersex conditions are not harmful to health and usually only affect reproduction, the term disorder to describe these individuals is not accurate.<\/p>\n<p>Chromosomes and gonads are not easy to see, so\u00a0often\u00a0the appearance of the external genitals is used to determine sex at birth.\u00a0However, as mentioned above, this\u00a0practice has historically led to the misclassification of intersex\u00a0people. In fact, this can have a number of consequences for the person in question, including a misunderstanding of their own bodies health, and difficulties navigating the medical system.\u00a0Rates of intersexuality within the human population are difficult to ascertain, especially considering the history of unethical medical intervention on intersex infants. There have been unfortunately many cases of doctors performing unnecessary corrective surgery in order to make the genitals of an intersex infant more \u201cnormal\u201d. Occasionally, the parents of the infant may not have been informed of the condition or procedure, nor given their consent. While this is justified as being done to provide the infant with a more normal life, most intersex advocacy groups are strongly opposed to this practice.\u00a0Often a person has no reason to suspect they are intersex until they reach puberty and, in some cases, it\u2019s only discovered\u00a0after the death of the individual.<\/p>\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>For more information on intersex conditions, check out the FAQ for\u00a0interACT, an advocacy group for intersex youth:\u00a0<a href=\"https:\/\/interactadvocates.org\/faq\/\" target=\"_blank\" rel=\"noopener\">https:\/\/interactadvocates.org\/faq\/<\/a><\/p>\n<\/div>\n<\/div>\n<h3>Prenatal Influences<\/h3>\n<p>The placenta\u00a0is a structure that develops during pregnancy and\u00a0provides nourishment and oxygen to the fetus. Almost everything the pregnant parent ingests, including food\u202fand\u202fmedication, travels through the placenta to the fetus,\u00a0hence the phrase \u201ceating for two.\u201d In fact, the parental\u202fenvironment\u00a0can have long-term effects on the developing fetus.\u00a0A\u202fteratogen\u202fis any environmental agent\u2014biological, chemical, or physical\u2014that causes damage to the developing embryo or fetus.\u00a0Most\u00a0teratogens have their greatest impact during early pregnancy.\u202fTake for example, lead, which can cause lead poisoning if the pregnant parent becomes\u202fexposed\u00a0from\u202fsources like paint or soil.\u202fSince the ban on\u00a0leaded\u00a0gasoline in the early 90\u2019s, levels in children has declined dramatically,\u202fyet\u202fchildhood lead poisoning remains a global health concern. Research shows that even extremely low levels of lead exposure can\u202fstill have\u202fnegative effects, including cognitive\u202fimpairments\u202f(Koller\u202fet al., 2004). In the United States alone, deaths related to lead poising are comparable to those caused by smoking tobacco, around 412,000 a year (O\u2019Connor et al., 2020).<\/p>\n<p>Many recreational\u202fdrugs,\u202flike\u00a0alcohol and tobacco\u202fare considered teratogens\u202fbecause\u00a0they can\u202fcross the placenta and\u00a0negatively\u00a0affect the fetus.\u202fOther teratogens include\u202fexposure to\u202fradiation and\u202fviruses such\u202fas HIV,\u202fherpes, and rubella (German measles). \u202fAdditionally, people who experience high stress during pregnancy are more likely to have children with enhanced responses to stress (Leung et al., 2010).<\/p>\n<section>\u00a0<\/section>\n<p><strong><a id=\"TTprenataldev\"><\/a>TRICKY TOPIC: PRENATAL DEVELOPMENT<\/strong><\/p>\n<p><iframe loading=\"lazy\" id=\"oembed-1\" title=\"Tricky Topics: Prenatal Development\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/vN2NRvyQ6Dc?feature=oembed&#38;rel=0\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p><em>If the video above does not load, click here:\u00a0<a href=\"https:\/\/youtu.be\/vN2NRvyQ6Dc\">https:\/\/youtu.be\/vN2NRvyQ6Dc<\/a><\/em><br \/>\n<em>For a full transcript of this video, click <a href=\"\/intropsychneuro\/back-matter\/appendix\/#prenataldev\">here<\/a><\/em><\/p>\n<h3 class=\"os-title\"><span style=\"font-size: 1em\">Infancy Through Childhood<\/span><\/h3>\n<section id=\"fs-idp16156640\">\n<p id=\"fs-idp84575904\">The average newborn weighs approximately 7.5 pounds. \u202fAlthough small, a newborn is not completely helpless because\u202ftheir\u202freflexes and sensory capacities help\u202fthem\u202finteract with the environment from the moment of birth. All healthy babies are born with\u202fnewborn reflexes: inborn automatic responses to\u202fspecific\u202fforms of stimulation. Reflexes help the newborn survive until\u202fthey&#8217;re\u202fcapable of more complex\u202fbehaviours\u2014these reflexes are crucial to survival. They are present in babies whose brains are developing normally and usually disappear around 4\u20135 months old. Let\u2019s\u202ftake a look\u202fat some of these newborn reflexes.<\/p>\n<p>The rooting reflex is the newborn\u2019s response to anything that touches their cheek: When you stroke a baby\u2019s cheek, they naturally\u202fturn\u202ftheir head in that direction and begin to suck. The sucking reflex is the automatic, unlearned, sucking motions that infants do with their mouths.\u202fYou can observe the grasping reflex\u202fif you put your finger into a newborn\u2019s hand,\u202fthey\u202fautomatically\u202fgrasp\u202fanything that touches their palms. The Moro reflex is the newborn\u2019s response when a baby feels like they are falling. The baby spreads their arms, pulls them back in, and then (usually) cries. How do you think these reflexes promote survival in the first months of life?<\/p>\n<div id=\"fs-idm31186432\" class=\"psychology link-to-learning ui-has-child-title\">\n<section>\n<div class=\"os-note-body\">\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\n<\/header>\n<div class=\"textbox__content\">Take a few minutes to view this brief\u00a0<a href=\"http:\/\/openstax.org\/l\/newflexes\" target=\"_blank\" rel=\"noopener nofollow\">video clip about newborn reflexes<\/a>\u00a0to learn more.<\/div>\n<\/div>\n<\/div>\n<\/section>\n<\/div>\n<p>What can young infants see, hear, and smell? Newborn infants\u2019 sensory abilities are significant, but their senses are not yet fully developed. Many of a newborn\u2019s innate preferences facilitate interaction with caregivers and other humans. Although vision is their least developed sense, newborns already show a preference for faces. Babies who are just a few days old also prefer human voices, they will listen to voices longer than sounds that do not involve speech (Vouloumanos\u202f&amp;\u202fWerker, 2004), and they seem to prefer the voice of the\u202fparent who was pregnant\u202fover a stranger\u2019s voice (Mills &amp;\u202fMelhuish, 1974). In an interesting experiment, 3-week-old babies were given pacifiers\u202fthat played a recording\u202fof the\u202fpregnant\u00a0parent\u2019s voice\u202fand of a stranger\u2019s voice. When the infants heard their parent\u2019s voice, they sucked more strongly at the pacifier (Mills &amp;\u202fMelhuish, 1974). Newborns also have a strong sense of smell. For instance, newborn babies can distinguish the smell of the\u202fparent who was pregnant\u202ffrom that of others. In a study by MacFarlane (1978), 1-week-old babies who were being breastfed were placed between two gauze pads. One gauze pad was from the bra of a nursing parent who was a stranger, and the other gauze pad was from the bra of the infant\u2019s own nursing parent. More than two-thirds of the week-old babies turned toward the gauze pad with their own nursing parent\u2019s scent.<\/p>\n<section id=\"fs-idm70473856\">\n<h4>Physical Development<\/h4>\n<p>During infancy, toddlerhood, and early childhood, the body\u2019s physical development is rapid.\u202fOn average,\u00a0newborns weigh between 5 and 10 pounds.\u202fBy 2 years old, this weight will have quadrupled,\u00a0with\u00a0most 2 year\u202folds\u202fweighing between 20 and 40 pounds (WHO\u202fMulticentre\u202fGrowth Reference Study Group, 2006).\u202f Growth slows between 4 and 6 years old. During this time children gain 5\u20137 pounds and grow about 2\u20133 inches per year.<\/p>\n<p>There are two important patterns of development: <strong>cephalocaudal<\/strong> and\u202f<strong>proximodistal<\/strong>. Cephalocaudal development refers to the pattern of growth from the head down, also referred to\u00a0as development from head to toe.\u202fProximodistal\u202fdevelopment is the tendency for growth to start in the\u202fcentre\u202fof the body and move outwards to the extremities. This is reflected in the development of more general motor skills of the limbs close to the torso before development of fine motor skills in the fingers and toes.<\/p>\n<div id=\"Figure_09_04_Growth\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 975px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" id=\"79062\" src=\"https:\/\/openstax.org\/resources\/4ad318b49b3059f225d0464d1044dfb3925d79e9\" alt=\"A collage of four photographs depicting babies is shown. From left to right they get progressively older. The far left photograph is a bundled up sleeping newborn. To the right is a picture of a toddler next to a toy giraffe. To the right is a baby blowing out a single candle. To the far right is a child on a swing set.\" width=\"975\" height=\"244\" \/><figcaption class=\"wp-caption-text\">Figure LD.10\u00a0Children experience rapid physical changes through infancy and early childhood. (credit &#8220;left&#8221;: modification of work by Kerry Ceszyk; credit &#8220;middle-left&#8221;: modification of work by Kristi Fausel; credit &#8220;middle-right&#8221;: modification of work by &#8220;devinf&#8221;\/Flickr; credit &#8220;right&#8221;: modification of work by Rose Spielman)<\/figcaption><\/figure>\n<\/figure>\n<\/div>\n<p>The\u202fnervous system continues to grow and develop\u202fafter\u202fbirth;\u202feach neural pathway forms thousands of new connections during infancy and toddlerhood. This period of rapid neural growth is called blooming. The blooming period of neural growth is then followed by a period of pruning, where neural connections are reduced. It is thought that pruning\u202fallows\u202fthe brain to function more efficiently, allowing for mastery of more complex skills (Hutchinson, 2011). Blooming occurs during the first few years of\u00a0life, and\u00a0pruning continues through childhood and into adolescence in various areas of the brain.<\/p>\n<p id=\"fs-idm2425248\">The size of our brains increases rapidly. For example, the brain of a 2-year-old is 55% of its adult size, and by 6 years old the brain is about 90% of its adult size (Tanner, 1978). During early childhood (ages 3\u20136), the frontal lobes grow rapidly.\u202fThe frontal lobes are associated with planning, reasoning, memory, and impulse control. Therefore, by the time children reach school age, they are developmentally capable of controlling their attention and\u202fbehaviour.\u00a0Through\u00a0the elementary\u00a0school years, the frontal, temporal, occipital, and parietal lobes all\u202fgrow in size. The brain growth spurts experienced in childhood tend to follow Piaget\u2019s sequence of cognitive development, so that significant changes in neural functioning are associated with\u202fcognitive advances (Kolb &amp;\u202fWhishaw, 2009; Overman,\u202fBachevalier, Turner, &amp;\u202fPeuster, 1992).<\/p>\n<p>Motor development occurs in an orderly sequence as infants move from reflexive reactions (e.g., sucking and rooting) to more advanced motor functioning.\u202fMotor skills\u202frefer to our ability to move our bodies and manipulate objects.\u202fFine motor skills\u202ffocus on the muscles in our fingers, toes, and eyes, and enable coordination of small actions (e.g., grasping a toy, writing with a pencil, and using a spoon).\u202fGross motor skills\u202ffocus on large muscle groups that control our arms and legs and involve larger movements (e.g., balancing, running, and jumping).<\/p>\n<p>As motor skills develop, there are certain developmental milestones that young children\u202ftypically\u202fachieve\u202fat certain age ranges\u202f(<a href=\"https:\/\/interactadvocates.org\/faq\/#Table_09_03_02\" target=\"_blank\" rel=\"noopener\">Table LD.4<\/a>)\u00a0An example of a developmental milestone is sitting. On average, most babies sit alone at 7 months old. Sitting involves both coordination and muscle strength, and 90% of babies achieve this milestone between 5 and 9 months old. \u202fIn another example, babies on average\u202fare able to\u202fhold up their head at 6 weeks old, and 90% of babies achieve this between 3 weeks and 4 months old.\u00a0If\u202fa\u202fchild is displaying delays on several milestones, that\u202fcould be\u202freason for concern\u202fsince some\u202fdevelopmental delays can be identified and addressed through early intervention.<\/p>\n<div id=\"Table_09_03_02\" class=\"os-table\">\n<table class=\"top-titled\" style=\"height: 189px\" summary=\"Table 9.4\">\n<thead>\n<tr style=\"height: 14px\">\n<th style=\"height: 14px;width: 899.062px\" colspan=\"5\" scope=\"col\">Table LD.4 Developmental Milestones, Ages 2\u20135 Years<\/th>\n<\/tr>\n<tr style=\"height: 29px\">\n<th style=\"height: 29px;width: 46.0625px\" scope=\"col\">Age (years)<\/th>\n<th style=\"height: 29px;width: 128.062px\" scope=\"col\">Physical<\/th>\n<th style=\"height: 29px;width: 195.062px\" scope=\"col\">Personal\/Social<\/th>\n<th style=\"height: 29px;width: 241.062px\" scope=\"col\">Language<\/th>\n<th style=\"height: 29px;width: 233.062px\" scope=\"col\">Cognitive<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"height: 29px\" valign=\"top\">\n<td style=\"height: 29px;width: 46.0625px\">2<\/td>\n<td style=\"height: 29px;width: 128.062px\">Kicks a ball; walks up and down stairs<\/td>\n<td style=\"height: 29px;width: 195.062px\">Plays alongside other children; copies adults<\/td>\n<td style=\"height: 29px;width: 241.062px\">Points to objects when named; puts 2\u20134 words together in a sentence<\/td>\n<td style=\"height: 29px;width: 233.062px\">Sorts shapes and colours; follows 2-step instructions<\/td>\n<\/tr>\n<tr style=\"height: 29px\" valign=\"top\">\n<td style=\"height: 29px;width: 46.0625px\">3<\/td>\n<td style=\"height: 29px;width: 128.062px\">Climbs and runs; pedals tricycle<\/td>\n<td style=\"height: 29px;width: 195.062px\">Takes turns; expresses many emotions; dresses self<\/td>\n<td style=\"height: 29px;width: 241.062px\">Names familiar things; uses pronouns<\/td>\n<td style=\"height: 29px;width: 233.062px\">Plays make believe; works toys with parts (levers, handles)<\/td>\n<\/tr>\n<tr style=\"height: 44px\" valign=\"top\">\n<td style=\"height: 44px;width: 46.0625px\">4<\/td>\n<td style=\"height: 44px;width: 128.062px\">Catches balls; uses scissors<\/td>\n<td style=\"height: 44px;width: 195.062px\">Prefers social play to solo play; knows likes and interests<\/td>\n<td style=\"height: 44px;width: 241.062px\">Knows songs and rhymes by memory<\/td>\n<td style=\"height: 44px;width: 233.062px\">Names colours and numbers; begins writing letters<\/td>\n<\/tr>\n<tr style=\"height: 44px\" valign=\"top\">\n<td style=\"height: 44px;width: 46.0625px\">5<\/td>\n<td style=\"height: 44px;width: 128.062px\">Hops and swings; uses fork and spoon<\/td>\n<td style=\"height: 44px;width: 195.062px\">Distinguishes real from pretend; likes to please friends<\/td>\n<td style=\"height: 44px;width: 241.062px\">Speaks clearly; uses full sentences<\/td>\n<td style=\"height: 44px;width: 233.062px\">Counts to 10 or higher; prints some letters and copies basic shapes<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1em;font-style: italic;font-weight: bold\">Cognitive Development<\/span><\/div>\n<\/div>\n<\/section>\n<section id=\"fs-idm68003168\">\n<p id=\"fs-idm83412368\">In addition to rapid physical growth, young children also exhibit significant development of their cognitive abilities. Piaget thought that children\u2019s ability to understand objects\u2014such as learning that a rattle makes a noise when shaken\u2014was a cognitive skill that develops slowly as a child matures and interacts with the environment. Today, developmental psychologists think Piaget was incorrect. Researchers have found that even very young children understand\u202fphysical properties of\u202fobjects long before they have\u202fdirect\u202fexperience with those objects (Baillargeon, 1987;\u202fBaillargeon, Li,\u202fGertner, &amp; Wu, 2011). For example, children as young as 3 months old demonstrated knowledge of the properties of objects that they had only viewed and did not have prior experience with them. In one study, 3-month-old infants were shown a truck rolling down a track and behind a screen. The box, which appeared solid but was\u202factually hollow, was placed next to the track. The truck rolled past the box as would be expected. Then the box was placed on the track to block the path of the truck. When the truck was rolled down the track this time, it continued unimpeded. The infants spent significantly more time looking at this impossible event (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_04_TruckBox\" target=\"_blank\" rel=\"noopener\">Figure LD.11<\/a>).\u202fBaillargeon\u202f(1987) concluded that they knew solid objects cannot pass through each other.\u202fBaillargeon\u2019s\u202ffindings suggest that very young children\u202fhave an understanding of\u202fobjects and how they work, which Piaget (1954) would have said is beyond their cognitive abilities due to their limited experiences in the world.<\/p>\n<div id=\"Figure_09_04_TruckBox\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 975px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"1415\" src=\"https:\/\/openstax.org\/resources\/4718c3bc0c5ee7b8424ca343b2d257e97ecf31ef\" alt=\"Image A shows a toy truck coasting along a track unobstructed. Image B shows a toy truck coasting along a track with a box in the background. Image C shows a truck coasting along a track and going through what appears to be an obstruction.\" width=\"975\" height=\"188\" \/><figcaption class=\"wp-caption-text\">Figure LD.11\u00a0In Baillargeon\u2019s study, infants observed a truck (a) roll down an unobstructed track, (b) roll down an unobstructed track with an obstruction (box) beside it, and (c) roll down and pass through what appeared to be an obstruction.<\/figcaption><\/figure>\n<\/figure>\n<div class=\"os-caption-container\">\n<p>Like physical milestones, there are also cognitive milestones\u202fchildren typically reach at certain ages. For example, infants shake their head \u201cno\u201d around 6\u20139 months, and they respond to verbal requests to do things like \u201cwave bye-bye\u201d or \u201cblow a kiss\u201d around 9\u201312 months. Remember Piaget\u2019s ideas about object permanence? \u202fWe can expect children to grasp the concept that objects continue to exist even when they are not in sight by around 8 months old. Because toddlers (i.e., 12\u201324 months old) have mastered\u00a0object permanence,\u00a0they enjoy games\u00a0like hide and seek, and they realize that when someone leaves the room they will come back (Loop, 2013). Toddlers also point to pictures in books and look in appropriate places when you ask them to find objects.<\/p>\n<\/div>\n<\/div>\n<p>Preschool-age children (i.e., 3\u20135 years old) also make steady progress in cognitive development. Not only can they count, name\u202fcolours, and tell you their name and age, but they can also make some decisions on their own, such as choosing an outfit to wear. Preschool-age children understand basic time concepts and sequencing (e.g., before and after), and they can predict what will happen next in a story. They also begin to enjoy the use of\u00a0humour\u00a0in stories. Because they can think symbolically, they enjoy pretend\u00a0play\u00a0and\u00a0inventing\u00a0elaborate characters and scenarios. One of the most common examples of their cognitive growth is their blossoming curiosity. Preschool-age children love to ask \u201cWhy?\u201d<\/p>\n<p>An important cognitive change occurs in children this age. Recall that Piaget described 2\u20133 year\u00a0olds\u00a0as egocentric, meaning that they do not have an awareness of others\u2019 points of view. Between 3 and 5 years old, children come to understand that people have thoughts, feelings, and beliefs that are different from their own. This is known as theory-of-mind (TOM). Children can use this skill to tease others, persuade their parents to purchase a candy bar, or understand why a sibling might be angry. When children develop TOM, they can recognize that others have false beliefs (Dennett, 1987; Callaghan et al., 2005).<\/p>\n<div id=\"fs-idp31181840\" class=\"psychology link-to-learning ui-has-child-title\">\n<section>\n<div class=\"os-note-body\">\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\n<\/header>\n<div class=\"textbox__content\">False-belief tasks are useful in determining a child\u2019s acquisition of theory-of-mind (TOM). Take a look at this\u00a0<a href=\"http:\/\/openstax.org\/l\/crayons\" target=\"_blank\" rel=\"noopener nofollow\">video clip that shows a false belief task involving a box of crayons<\/a>\u00a0to learn more.<\/div>\n<\/div>\n<\/div>\n<\/section>\n<\/div>\n<p>Cognitive skills continue to expand in middle and late childhood (6\u201311 years old). Thought processes become more logical and organized when dealing with concrete information (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_04_Game\" target=\"_blank\" rel=\"noopener\">Figure LD.12<\/a>). Children at this age understand concepts such as the past, present, and future, giving them the ability to plan and work toward goals. Additionally, they can process complex ideas such as addition and subtraction and cause-and-effect relationships.<\/p>\n<div id=\"Figure_09_04_Game\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 325px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"85680\" src=\"https:\/\/openstax.org\/resources\/79444ed5208262b28fcaeca69235ae3c0b56ef71\" alt=\"A photograph of children playing baseball is shown. Five children are in the picture, two on one team, and three on the other.\" width=\"325\" height=\"215\" \/><figcaption class=\"wp-caption-text\">Figure LD.12\u00a0Because they understand luck and fairness, children in middle and late childhood (6\u201311 years old) are able to follow rules for games. (credit: Edwin Martinez)<\/figcaption><\/figure>\n<\/figure>\n<\/div>\n<p>One well-researched aspect of cognitive development is language acquisition.\u202fThe order in which children learn language structures is consistent across children and cultures (Hatch, 1983).\u202fStarting before birth, babies begin to develop language and communication skills. At birth, babies apparently recognize the voice of their birth parent, and can discriminate between the language(s) spoken by their\u202fbirth parent\u202fand foreign languages, and they show preferences for faces that are moving in synchrony with audible language (Blossom &amp; Morgan, 2006; Pickens, 1994;\u202fSpelke\u202f&amp; Cortelyou, 1981).<\/p>\n<p>Children communicate information through gesturing long before they speak, and there is some evidence that gesture usage predicts subsequent language development (Iverson &amp; Goldin-Meadow, 2005). In terms of producing spoken language, babies begin to\u00a0coo\u00a0almost immediately. Cooing is a one-syllable combination of a consonant and a vowel sound (e.g., coo or\u202fba). Interestingly, babies replicate sounds from their own languages. A baby whose parents speak French will coo in a different tone than a baby whose parents speak Spanish or Urdu. After cooing, the baby starts to babble. Babbling begins with repeating a syllable, such as\u00a0ma-ma, da-da, or\u202fba-ba. When a baby is about 12 months old, we expect them to say their first word for meaning, and to start combining words for meaning at about 18 months.<\/p>\n<p>At about 2 years old, a toddler uses between 50 and 200 words; by 3 years old they have a vocabulary of up to 1,000 words and can speak in sentences. During the early childhood years, children&#8217;s vocabulary increases at a rapid pace. This is sometimes referred to as the \u201cvocabulary spurt\u201d and has been claimed to involve an expansion in vocabulary at a rate of 10\u201320 new words per week. Recent research may indicate that while some children experience these spurts, it is far from universal (as discussed in Ganger &amp; Brent, 2004). It has been estimated\u00a0that,\u00a05 year\u00a0olds\u00a0understand about 6,000 words, speak 2,000 words, and can define words and question their meanings. They can rhyme and name the days of the week. Seven year\u00a0olds\u00a0speak fluently and use slang and clich\u00e9s (Stork &amp;\u202fWiddowson, 1974).<\/p>\n<p>What accounts for such dramatic language learning by children? Behaviorist B. F. Skinner thought that we learn language in response to reinforcement or feedback, such as through parental approval or\u202fsimply by\u202fbeing understood. For example, when a two-year-old child asks for juice, they might say, \u201cme juice,\u201d to which their parent might respond by giving them a cup of apple juice. Noam Chomsky (1957) criticized Skinner\u2019s theory and proposed that we are all\u00a0born with an innate capacity to learn language. Chomsky called this mechanism a language acquisition device (LAD). Researchers now believe that language acquisition is partially inborn and partially learned through our interactions with our linguistic environment (Gleitman\u202f&amp; Newport, 1995; Stork &amp;\u202fWiddowson, 1974).<\/p>\n<\/section>\n<section id=\"fs-idm42075248\">\n<h4>Attachment<\/h4>\n<p>Psychosocial development occurs as children form relationships, interact with others, and understand and manage their feelings. In social and emotional development, forming healthy attachments is very important and is the major social milestone of infancy.\u202fAttachment\u202fis a long-standing connection or bond with others\u202fand is often used to describe the emotional bond between child and caregiver. Attachment is more easily established during the early years of a child&#8217;s life and is therefore thought to be reflective of a sensitive period. Developmental psychologists are interested in how infants reach this milestone. They ask such questions as: How do parent and infant attachment bonds form? How does neglect affect these bonds? What accounts for children\u2019s attachment differences?<\/p>\n<p>Researchers Harry Harlow, John Bowlby, and Mary Ainsworth conducted studies designed to answer these questions. In the 1950s, Harlow conducted a series of experiments on monkeys. He separated newborn monkeys from their mothers. Each monkey was presented with two surrogate mothers. One surrogate monkey was\u00a0made out of\u00a0wire mesh, and dispensed\u202fmilk. The other monkey was softer and made from cloth: This monkey did not dispense milk. Research shows that the monkeys preferred the soft, cuddly cloth monkey, even though it did not provide any nourishment. The baby monkeys spent their time clinging to the cloth monkey and only went to the wire monkey when they needed to be fed. Prior to this study, the medical and scientific communities generally thought that babies become attached to the people who provide their nourishment.\u202fHowever, Harlow (1958) concluded that there was more to the\u202fbirth parent-child bond than nourishment. Feelings of comfort and security are the\u202fcritical components to parental-infant bonding, which leads to healthy psychosocial development.<\/p>\n<div id=\"fs-idp31454704\" class=\"psychology link-to-learning ui-has-child-title\">\n<section>\n<div class=\"os-note-body\">\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\n<\/header>\n<div class=\"textbox__content\">Harlow\u2019s studies of monkeys were performed before modern ethics guidelines were in place, and today his experiments are widely considered to be unethical and even cruel. Watch this\u00a0<a href=\"http:\/\/openstax.org\/l\/monkeystudy\" target=\"_blank\" rel=\"noopener nofollow\">video of actual footage of Harlow&#8217;s monkey studies<\/a>\u00a0to learn more.<\/div>\n<\/div>\n<\/div>\n<\/section>\n<\/div>\n<p>Building on the work of Harlow and others, John Bowlby developed the concept of attachment theory. He defined attachment as the affectional bond that\u202fan\u202finfant forms\u202fwith the parent who birthed them\u202f(Bowlby, 1969). An infant must form this bond with a primary caregiver in order to have normal social and emotional development. In addition, Bowlby proposed that this attachment bond is very powerful and continues throughout life. He used the concept of secure base to define a healthy attachment between parent and child (1988). A\u202fsecure base\u202fis a parental presence that gives the child a sense of safety as he explores his surroundings. Bowlby said that two things are needed for a healthy attachment: The caregiver must be responsive to the child\u2019s physical, social, and emotional needs; and the caregiver and child must engage in mutually enjoyable interactions (Bowlby, 1969) (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_04_BabySmile\" target=\"_blank\" rel=\"noopener\">Figure LD.13<\/a>).<\/p>\n<div id=\"Figure_09_04_BabySmile\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 487px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"32769\" src=\"https:\/\/openstax.org\/resources\/b264621e863ce1b7a80d3858e981efbecdf548c2\" alt=\"A man holds a baby in the air.\" width=\"487\" height=\"334\" \/><figcaption class=\"wp-caption-text\">Figure LD.13\u00a0Mutually enjoyable interactions promote the parent-infant bond. (credit: &#8220;balouriarajesh_Pixabay&#8221;\/Pixabay)<\/figcaption><\/figure>\n<\/figure>\n<div class=\"os-caption-container\">\n<p>While Bowlby thought attachment was an all-or-nothing process, Mary Ainsworth\u2019s (1970) research showed otherwise. Ainsworth wanted to know if children differ in the ways they bond, and if so, why. To find the answers, she used the Strange Situation procedure to study attachment between\u00a0parents\u00a0and their infants (1970).\u202fIn the Strange Situation, the\u202fprimary caregiver and\u00a0child\u00a0(age 12-18 months) are placed in a room together. There are toys in the room, and the caregiver and child spend some time alone in the room. After the child has had time to explore their surroundings, a stranger enters the room. The caregiver then leaves the baby with the stranger. After a few minutes, the caregiver returns to comfort their child.<\/p>\n<\/div>\n<\/div>\n<p id=\"fs-idp113719280\">Based on how the infants\/toddlers responded to the separation and reunion, Ainsworth identified three types of parent-child attachments: secure, avoidant, and resistant (Ainsworth &amp; Bell, 1970). A fourth style, known as disorganized attachment, was later described (Main &amp; Solomon, 1990). The most common type of attachment\u202fis called\u202fsecure attachment\u202f(<a href=\"https:\/\/youtu.be\/vN2NRvyQ6Dc#Figure_09_04_Secure\" target=\"_blank\" rel=\"noopener\">Figure LD.14<\/a>). In this type of attachment, the toddler prefers their parent over a stranger. The attachment figure is used as a secure base to explore the environment and is sought out in times of stress. Securely attached children were distressed when their caregivers left the room in the Strange Situation experiment, but when their caregivers returned, the securely attached children were happy to see them. Securely attached children have caregivers who are sensitive and responsive to their needs.<\/p>\n<div id=\"Figure_09_04_Secure\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 488px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"97859\" src=\"https:\/\/openstax.org\/resources\/1fb890e1e5af46b6e33a2799a1f5e85fac3f1f51\" alt=\"A photograph shows a person squatting down next to a small child who is standing up.\" width=\"488\" height=\"365\" \/><figcaption class=\"wp-caption-text\">Figure LD.14\u00a0In secure attachment, the parent provides a secure base for the toddler, allowing them to securely explore his environment. (credit: Kerry Ceszyk)<\/figcaption><\/figure>\n<\/figure>\n<div class=\"os-caption-container\">\n<p>With\u202favoidant attachment, the child is unresponsive to the parent, does not use the parent as a secure base, and does not\u202fappear\u202fto\u00a0care if the parent leaves. The toddler reacts to the parent the same way they react to a stranger. When the parent does return, the child is slow to show a positive reaction. Ainsworth theorized that these children were most likely to have a caregiver who was inattentive to their needs (Ainsworth,\u202fBlehar, Waters, &amp; Wall, 1978).<\/p>\n<\/div>\n<\/div>\n<p>In cases of\u202fresistant attachment, children tend to show clingy\u202fbehaviour, but then they reject the attachment figure\u2019s attempts to interact with them (Ainsworth &amp; Bell, 1970). These children do not explore the toys in the room, as they are too fearful. During separation in the Strange Situation, they became extremely disturbed and angry with the parent. When the parent returns, the children are difficult to comfort. Resistant attachment is the result of the caregivers\u2019 inconsistent level of response to their child.<\/p>\n<p>Finally, children with\u202fdisorganized attachment\u202fbehaved oddly in the Strange Situation. They freeze, run around the room in an erratic manner, or try to run away when the caregiver returns (Main &amp; Solomon, 1990). This type of attachment is seen most often in kids who have been abused. Research has shown that abuse disrupts a child\u2019s ability to regulate their emotions.<\/p>\n<p>While Ainsworth\u2019s research has found support in subsequent studies, it has also met criticism. Some researchers have pointed out that a child\u2019s temperament may have a strong influence on attachment (Gervai, 2009; Harris, 2009), and others have noted that attachment varies from culture to culture, a factor not accounted for in Ainsworth\u2019s research (Rothbaum, Weisz, Pott, Miyake, &amp; Morelli, 2000; van\u202fIjzendoorn\u202f&amp;\u202fSagi-Schwartz, 2008).<\/p>\n<div id=\"fs-idm1064944\" class=\"psychology link-to-learning ui-has-child-title\">\n<section>\n<div class=\"os-note-body\">\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\n<\/header>\n<div class=\"textbox__content\">Watch this\u00a0<a href=\"http:\/\/openstax.org\/l\/strangesitu\" target=\"_blank\" rel=\"noopener nofollow\">video clip of the Strange Situation<\/a>\u00a0and try to identify which type of attachment baby Lisa exhibits.<\/div>\n<\/div>\n<\/div>\n<\/section>\n<\/div>\n<\/section>\n<section id=\"fs-idm42031072\">\n<h4>Self-Concept<\/h4>\n<p>Just as attachment is the main psychosocial milestone of infancy, the primary psychosocial milestone of childhood is the development of a positive sense of self. How does self-awareness develop?\u202fIf you place a baby in front of a mirror, they will reach out to touch their image, thinking it is another baby. However, by about 18 months a toddler will recognize that the person in the mirror is them. How do we know this? In a well-known experiment, a researcher placed a red dot of paint on children\u2019s noses before putting them in front of a mirror (Amsterdam, 1972). Commonly known as the mirror test, this\u202fbehaviour\u202fis demonstrated by humans and a few other species and is considered evidence of self-recognition (Archer, 1992). At 18 months\u202fold\u202fthey would touch their own noses when they saw the paint, surprised to see a spot on their faces. By 24\u201336 months old children can name and\/or point to themselves in pictures, clearly indicating self-recognition.<\/p>\n<p>Children from 2\u20134 years old display a great increase in social\u202fbehaviour\u202fonce they have established a self-concept. They enjoy playing with other children, but they have difficulty sharing their possessions.\u202fAlso, through play children explore and come to explore gender roles (Chick,\u202fHeilman-Houser, &amp; Hunter, 2002).\u202fBy 4 years old, children can cooperate with other children, share when asked, and separate from parents with little anxiety. Children at this age also exhibit autonomy, initiate tasks, and carry out plans. Success in these areas contributes to a positive sense of self. Once children reach 6 years old, they can identify themselves in terms of group memberships: \u201cI\u2019m a first grader!\u201d School-age children compare themselves to their peers and discover that they are competent in some areas and less so in others (recall Erikson\u2019s task of industry versus inferiority). At this age, children recognize their own personality traits as well as some other traits they would like to have. For example, 10-year-old\u202fAlix\u202fsays, \u201cI\u2019m kind of shy. I wish I could be more talkative like my friend Ro.\u201d<\/p>\n<p>Development of a positive self-concept is important to healthy development. Children with a positive self-concept tend to be more confident, do better in school, act more independently, and are more willing to try new activities (Maccoby, 1980; Ferrer &amp; Fugate, 2003). Formation of a positive self-concept begins in Erikson\u2019s toddlerhood stage, when children establish autonomy and become confident in their abilities. Development of self-concept continues in elementary school, when children compare themselves to others. When the comparison is\u202ffavourable, children feel a sense of competence and are motivated to work harder and accomplish more. Self-concept is re-evaluated in Erikson\u2019s adolescence stage, as teens form an identity. They\u00a0internalize the messages they have received regarding their strengths and weaknesses, keeping some messages and rejecting others. Adolescents who have achieved identity formation\u00a0are capable of contributing\u00a0positively to society (Erikson, 1968).<\/p>\n<div class=\"psychology dig-deeper ui-has-child-title\">\n<section>\n<div><\/div>\n<div class=\"os-note-body\"><span style=\"text-align: initial;font-size: 1em\">One behavioural aspect that contributes to children\u2019s developing sense of self-identity is play. Children spend a significant portion of their day playing,\u202fpre-schoolers\u202foften\u00a0spending\u202fmost\u202fof the day engaged in some sort of play activity (Malloy, 2020). Play is an important aspect of social and cognitive development as it makes social learning something children desire to engage in. Play also provides the space for children to begin practicing social skills such as\u202fhumour, which has been found to have influence on peer acceptance and perceived social competence. It has even been argued that play is an essential element in the acquisition of language and concept meaning.\u202fGiven this, it seems reasonable to assume that the interest children take in play and\u00a0developmental concepts like self-concept, motivation, learning and security in relationships (Lillemyr\u202fet al., 2010).\u202f\u00a0<\/span><\/div>\n<\/section>\n<\/div>\n<\/section>\n<p>Children develop a personal sense of play style at as young as the second year\u00a0to\u00a0life. It\u2019s at this stage we see children start to make choices of individuation, such as toy preference. Toy preference is one of the earliest places we begin to see children develop a sense of gender identity,\u202fone study\u202fshowed\u202fgender-based toy preferences at as young as 12-months old (Servin,\u00a0Bohlin, and Berlin, 1999). One might expect that children would show a preferential bias towards toys assigned to the same sex-category as the biological sex of the child, with\u00a0AFAB\u00a0children showing a higher preference for \u201cgirls\u2019 toys\u201d and AMAB children showing a higher preference for \u201cboys\u2019 toys\u201d. However, the full story is more complex. Parents and authority figures begin instilling children with gender norms based on their own cultural expectations of gender from the moment the child is born. (van\u202fde\u00a0Beek\u00a0et al., 2006). Because of this, it is possible that children\u2019s expressions of self may be influenced by the expectation that there is a correct way for them to perform self-hood. It\u00a0also\u00a0worth keeping in mind that many studies looking at expressions of gender mistakenly use a circular definition in the construction of their categories. A circular definition is a definition that uses one or more of the terms being defined as part of its definition. For instance, it would be circular to claim that violent video\u00a0game\u00a0cause teenagers to be violent because violent teenagers play violent video games.<\/p>\n<p>Take for instance a study which attempted to measure the rate at which infants preferred toys assigned to the same gender category assigned to the infant\u202f(Alexander et al, 2009). To do this, they tracked rates at which infants visually fixated on one of two toys; a doll (the \u201cgirls\u2019 toy\u201d) or a truck (the \u201cboys\u2019 toy\u201d)\u202fand\u202fcompared the amount of time\u202fAFAB and AMAB\u202fchildren spent fixated on each toy. The published study claims to have found notable discrepancies in gender-based toy preference. However, there are two major issues. First, the study uses a circular definition in constructing its\u202ftoy\u202fcategories. The researchers designated the doll a \u201cgirls\u2019 toy\u201d as it was the toy preferred by girls based on the presumption that girls prefer them. The second problem with this study is that their results do not support their claim.\u202fBased on average\u202fvisual fixating on each object, AFAB infants preferred the doll to the truck.\u202f AFAB infants spent approximately the same amount of time fixated on the truck as AMAB infants, and AMAB infants\u202factually spent\u202fslightly longer looking\u202fat\u202fthe doll than the truck (though\u202fthis difference was quite small).\u202fThis\u202funderscores the importance of critically evaluating published\u202fscientific\u202fstudies to\u202fso as to\u202fnot mistakenly believe false or misinterpreted conclusions.<\/p>\n<p>So, what can\u202fwe conclude about children\u2019s early\u202ftoy preferences and play style? Generally, there are two perspectives on childhood development, one based\u00a0in\u00a0the social environment of the child, and one based more in biology.\u202fThe social environment perspective posits that children\u2019s preferences are influenced by parents and authority figures (such as teachers) who can reinforce or discourage a child\u2019s preferences. The biological perspective claims that children\u2019s preferences are\u202finfluenced\u202fby\u202fgonadal\u202fhormones,\u202flike testosterone\u202f(Servin,\u00a0Bohlin, and Berlin, 1999),\u202fwhich is associated with\u202fpreference for stereotypically masculine toys\u202fand\u202fphysically active \u201crough and tumble\u201d play (van de\u00a0Beek\u00a0et al., 2006).\u202fBoth the social environment and the presence of hormones\u202fare associated with\u202fchildren\u2019s\u202ftoy\u202fpreferences,\u202fplay-style, and self-concept (Servin,\u00a0Bohlin, and Berlin, 1999; Chick et al, 2002).<\/p>\n<div id=\"fs-idp15890800\" class=\"psychology everyday-connection ui-has-child-title\">\n<section>\n<div class=\"os-note-body\">\n<div class=\"textbox textbox--examples\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">EVERYDAY CONNECTION<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<h4 id=\"83781\" class=\"os-subtitle\"><span class=\"os-subtitle-label\">The Importance of Play and Recess<\/span><\/h4>\n<p>According to the American Academy of Pediatrics (2007), unstructured play is an integral part of a child\u2019s development. It builds creativity, problem solving skills, and social relationships. Play also allows children to develop a theory-of-mind as they imaginatively take on the perspective of others.<\/p>\n<p>Outdoor play allows children the opportunity to directly experience and sense the world around them. While doing so, they may collect objects that they come across and develop lifelong interests and hobbies. They also benefit from increased\u00a0exercise and\u00a0engaging in outdoor play can\u00a0actually increase\u00a0how much they enjoy physical activity. This helps support the development of a healthy heart and brain.\u202fResearch suggests that today\u2019s children are engaging in less and less outdoor play (Clements, 2004).\u202fWhile it is true that easier access to calorie-dense food has led to an increase in levels of childhood obesity, this alone does not explain the decrease in physical activity. There are\u00a0actually a\u00a0number of factors that may contribute to this decrease in physical activity. Easier access to calorie-dense foods have contributed to increased levels of childhood obesity. It has also become more difficult for children to both access the space required for physical activity and feel safe doing so. Due to parental concerns about things like road safety and stranger danger, children these days have low levels of independent mobility (ie. freedom to travel outdoors without adult supervision). This means that children frequently lack the opportunity to play outdoors. Additionally, factors such as playground\u00a0overcrowding\u00a0and the presence of teenagers\/older children\u00a0has\u00a0been shown to decrease physical activity in children. Play spaces designed to encourage structured activities like team sports may not appeal to all children, many of whom are shown to be more physically active when engaged in activities like creating things or using their imaginations. It has also been shown that children who cross perceived gender norms are likely to be the targets of bullying and\/or disapproval from their peers and elders. Due to the gender stereotypes associated with different forms of physical activity, it seems likely that some children may choose to not engage in a physical activity to avoid harassment (inversely, some may choose to participate in an activity solely to avoid the same harassment) (Reimers\u202fet al., 2018).<\/p>\n<p>Despite the adverse consequences associated with reduced play, some children are over scheduled and have little free time to engage in unstructured play. In addition, some schools have taken away recess time for children in a push for students to do better on standardized tests, and many schools commonly use loss of recess as a form of punishment. Do you agree with these practices? Why or why not?<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n<\/div>\n<\/section>\n<section id=\"fs-idm9670032\">\n<h3>Adolescence<\/h3>\n<p id=\"fs-idp31435184\">Adolescence is a socially constructed concept. In pre-industrial society, children were considered adults when they reached physical maturity, but today we have an extended time between childhood and adulthood called adolescence.\u202fAdolescence\u202fis the period of development that begins at puberty and ends at emerging adulthood, which is discussed later. In the United States, adolescence is seen as a time to develop independence from parents while remaining connected to them (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_04_Adolescent\" target=\"_blank\" rel=\"noopener\">Figure LD.15<\/a>). The typical age range of adolescence is from 12 to 18 years, and this stage of development also has some predictable physical, cognitive, and psychosocial milestones.<\/p>\n<div id=\"Figure_09_04_Adolescent\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 325px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"72952\" src=\"https:\/\/openstax.org\/resources\/0b823efdca083be0d94ab78e28f2efa6672be364\" alt=\"A photograph captures four people midair as they hold hands and jump.\" width=\"325\" height=\"168\" \/><figcaption class=\"wp-caption-text\">Figure LD.15\u00a0Peers are a primary influence on our development in adolescence. (credit: &#8220;manseok_Pixabay&#8221;\/ Pixabay)<\/figcaption><\/figure>\n<\/figure>\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1em;font-style: italic;font-weight: bold\">Physical Development<\/span><\/div>\n<\/div>\n<section id=\"fs-idm75846112\">As noted above, adolescence begins with puberty. While the sequence of physical changes in puberty is predictable, the onset and pace of puberty vary widely. Several physical changes occur during puberty, such as\u202fadrenarche\u202fand\u202fgonadarche, the maturing of the adrenal glands and sex glands, respectively.\u00a0Also\u00a0during this time, primary and secondary sexual characteristics develop and mature.\u202fPrimary sexual characteristics\u202fare organs specifically needed for reproduction, like the uterus, ovaries, and testes.\u202fSecondary sexual characteristics\u202fare physical signs of sexual maturation that do not directly involve sex organs, such as\u202fdevelopment of breasts and hips,\u202fdevelopment of facial hair and a deepened voice.\u202fAround half of children will\u202fexperience\u202fmenarche, the beginning of menstrual periods, usually around 12\u201313 years old. The other half\u202fwill\u202fexperience\u202fspermarche, the first ejaculation, around 13\u201314 years old. Sexual development is triggered by an increase in secretion of hormones\u202feither from the ovaries or\u202fthe testes.<\/p>\n<p>During puberty,\u202fmost people\u202fexperience a rapid increase in height (i.e., growth spurt). For those going through\u00a0an estrogen-dominated puberty, this\u202fbegins between 8 and 13 years old, with adult height reached between 10 and 16 years old.\u202fThose going through\u00a0a testosterone-dominated\u202fpuberty\u202fbegin their growth spurt slightly later, usually between 10 and 16 years old, and reach their adult height between 13 and 17 years old.\u202fBoth nature (i.e., genes) and nurture (e.g., nutrition, medications, and medical conditions) can influence height.<\/p>\n<p id=\"fs-idm78910480\">Because rates of physical development vary so widely among teenagers, puberty can be a source of pride or embarrassment. Early maturing males tend to be stronger, taller, and more athletic than their later maturing peers. They are usually more popular, confident, and independent, but they are also at a greater risk for substance abuse and early sexual activity (Flannery, Rowe, &amp; Gulley, 1993; Kaltiala-Heino, Rimpela, Rissanen, &amp; Rantanen, 2001). Early maturing females may be teased or overtly admired, which can cause them to feel self-conscious about their developing bodies. These females are at a higher risk for depression, substance abuse, and eating disorders (Ge, Conger, &amp; Elder, 2001; Graber, Lewinsohn, Seeley, &amp; Brooks-Gunn, 1997; Striegel-Moore &amp; Cachelin, 1999). Late blooming males and females (i.e., they develop more slowly than their peers) may feel self-conscious about their lack of physical development. Negative feelings are particularly a problem for late maturing males, who are at a higher risk for depression and conflict with parents (Graber et al., 1997) and more likely to be bullied (Pollack &amp; Shuster, 2000).<\/p>\n<p id=\"fs-idp52884496\">The adolescent brain also remains under development. Up until puberty, brain cells continue to bloom in the frontal region. Adolescents engage in increased risk-taking\u202fbehaviours\u202fand emotional\u00a0outbursts\u00a0possibly because the frontal lobes of their brains are still developing (<a href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-3-stages-of-development#Figure_09_04_TeenBrain\" target=\"_blank\" rel=\"noopener\">Figure LD.16<\/a>). Recall that this area is responsible for judgment, impulse control, and planning, and it is still maturing into early adulthood (Casey,\u202fTottenham, Liston, &amp;\u202fDurston, 2005).<\/p>\n<div id=\"Figure_09_04_TeenBrain\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 487px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"78201\" src=\"https:\/\/openstax.org\/resources\/1aefd4ccc54684d8afae35da46828327e4a182f5\" alt=\"An illustration of a brain is shown with the frontal lobe labeled.\" width=\"487\" height=\"362\" \/><figcaption class=\"wp-caption-text\">Figure LD.16\u00a0Brain growth continues into the early 20s. The development of the frontal lobe, in particular, is important during this stage.<\/figcaption><\/figure>\n<\/figure>\n<\/div>\n<div id=\"fs-idp97645824\" class=\"psychology link-to-learning ui-has-child-title\">\n<section>\n<div class=\"os-note-body\">\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">LINK TO LEARNING<\/p>\n<\/header>\n<div class=\"textbox__content\">According to neuroscientist Jay Giedd in the Frontline video \u201cInside the Teenage Brain\u201d (2013), \u201cIt\u2019s sort of unfair to expect [teens] to have adult levels of organizational skills or decision-making before their brains are finished being built.\u201d Watch this segment on\u00a0<a href=\"http:\/\/openstax.org\/l\/wiringbrain\" target=\"_blank\" rel=\"noopener nofollow\">\u201cThe Wiring of the Adolescent Brain\u201d<\/a>\u00a0to find out more about the developing brain during adolescence.<\/div>\n<\/div>\n<\/div>\n<p><strong><a id=\"TTmyeprecor\"><\/a>TRICKY TOPIC: MYELINATION OF THE PREFRONTAL CORTEX<br \/>\n<\/strong><\/p>\n<p><iframe loading=\"lazy\" id=\"oembed-2\" title=\"Tricky Topics: Myelination of the Prefrontal Cortex\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/DHljv1t2_uk?feature=oembed&#38;rel=0\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p><em>If the video above does not load, click here:\u00a0<a href=\"https:\/\/youtu.be\/DHljv1t2_uk\">https:\/\/youtu.be\/DHljv1t2_uk<\/a><\/em><br \/>\n<em>For a full transcript of this video, click <a href=\"\/intropsychneuro\/back-matter\/appendix\/#myeprecor\">here<\/a><\/em><\/p>\n<\/section>\n<\/div>\n<\/section>\n<section id=\"fs-idp64913392\">\n<h4>Cognitive Development<\/h4>\n<p>More complex thinking abilities emerge during adolescence. Some researchers suggest this is due to increases in processing speed and efficiency rather than as the result of an increase in mental capacity\u2014in other words, due to improvements in existing skills rather than development of new ones (Bjorkland, 1987; Case, 1985). During adolescence, teenagers move beyond concrete thinking and become capable of abstract thought. Recall that Piaget refers to this stage as formal operational thought. Teen thinking is also characterized by the ability to consider multiple points of view, imagine hypothetical situations, debate ideas and opinions (e.g., politics, religion, and justice), and form new ideas (<a href=\"http:\/\/openstax.org\/l\/monkeystudy#Figure_09_04_Reasoning\" target=\"_blank\" rel=\"noopener\">Figure LD.17<\/a>). In addition, it\u2019s not uncommon for adolescents to question authority or challenge established societal norms.<\/p>\n<p id=\"fs-idm18304048\">Cognitive empathy, also known as theory-of-mind (which we discussed earlier\u00a0with regard to\u00a0egocentrism), relates to the ability to take the perspective of others and feel concern for others\u00a0(Shamay-Tsoory,\u202fTomer, &amp;\u202fAharon-Peretz, 2005). Cognitive empathy begins to increase in adolescence and is an important component of social problem solving and conflict avoidance.<\/p>\n<div id=\"Figure_09_04_Reasoning\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 325px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"90931\" src=\"https:\/\/openstax.org\/resources\/d469b961542c10b3cb934657648deb27d55c5e38\" alt=\"A picture shows four people gathered around a table attempting to figure out a problem together.\" width=\"325\" height=\"217\" \/><figcaption class=\"wp-caption-text\">Figure LD.17\u00a0Teenage thinking is characterized by the ability to reason logically and solve hypothetical problems such as how to design, plan, and build a structure. (credit: U.S. Army RDECOM)<\/figcaption><\/figure>\n<\/figure>\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1em;font-style: italic;font-weight: bold\">Psychosocial Development<\/span><\/div>\n<\/div>\n<\/section>\n<section id=\"fs-idm2098944\">Adolescents continue to refine their sense of self as they relate to others. Erikson referred to the task of the adolescent as one of identity versus role confusion. Thus, in Erikson\u2019s view, an adolescent\u2019s main questions are \u201cWho am I?\u201d and \u201cWho do I want to be?\u201d Some adolescents adopt the values and roles that their parents expect for them. Other teens develop identities that are in opposition to their parents but align with a peer group. This is common as peer relationships become a central focus in adolescents\u2019 lives.<\/p>\n<p>As adolescents work to form their identities, they pull away from their parents, and the peer group becomes very important (Shanahan, McHale, Osgood, &amp;\u202fCrouter, 2007). Despite spending less time with their parents, most teens report positive feelings toward them (Moore, Guzman, Hair,\u202fLippman, &amp; Garrett, 2004). Warm and healthy parent-child relationships have been associated with positive child outcomes, such as better grades and fewer school\u202fbehaviour\u202fproblems, in the United States as well as in other countries (Hair et al., 2005).<\/p>\n<p>It appears that most teens don\u2019t experience adolescent\u00a0storm\u00a0and stress to the degree once famously suggested by G. Stanley Hall, a pioneer in the study of adolescent development. Only small numbers of teens have major conflicts with their parents (Steinberg &amp; Morris, 2001), and most disagreements are minor. For example, in a study of over 1,800 parents of adolescents from various cultural and ethnic groups, Barber (1994) found that conflicts occurred over day-to-day issues such as homework, money, curfews, clothing, chores, and friends. These types of arguments tend to decrease as teens develop (Galambos\u202f&amp; Almeida, 1992). There is emerging research on the adolescent brain. Galvan, Hare, Voss, Glover and Casey (2007) examined its role in risk-taking\u202fbehaviour. They used fMRI to assess the readings\u2019 relationship to risk-taking, risk perception, and impulsivity. The researchers found that there was no correlation between brain activity in the neural reward\u202fcentre\u202fand impulsivity and risk perception. However, activity in that part of the brain was correlated to risk taking. In other words, risk-taking adolescents experienced brain activity in the reward\u202fcentre. The idea that adolescents, however, are\u202fbut\u202fmore\u00a0impulsive than other demographics was challenged in their research, which included children and adults.<\/p>\n<\/section>\n<\/section>\n<section id=\"fs-idp16033584\">\n<section id=\"fs-idp7178272\">\n<div id=\"zip-idm245833632\" class=\"psychology link-to-learning ui-has-child-title\">\n<section>\n<div class=\"os-note-body\">\n<div class=\"textbox textbox--exercises\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">DIG DEEPER<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<h4>Developmental Trajectories among Indigenous populations in Canada:\u00a0The Impact of the Indian Residential School System<\/h4>\n<p>Childhood and adolescence are life stages pivotal to someone\u2019s developmental maturation (Cabral &amp; Patel, 2020; Cassidy &amp; Shaver, 2018; White et al., 2017). Experiences such as adversity, loss, trauma, and\/or maltreatment have been linked to feelings of anxiety and depression (Hovens et al., 2015; Jurena et al., 2020) as well as issues with attachment in older adult relationships (Cohen et al., 2012; Lo et al., 2017), issues in development (Sege et al., 2017), and other health problems (Asselmann et al., 2018; Nelson et al., 2020; Rojo-Wissar et al., 2021).<\/p>\n<p>Since confederation (1867), the Canadian federal government has continued to forcefully attempt total assimilation of Indigenous peoples into \u201cEuro-Canadian culture and society\u201d (Truth and Reconciliation Commission [TRC], 2015). One of the ways in which the government has attempted to do this was through the Indian Residential School (IRS) system (TRC, 2015). The IRS system in Canada has often been referred to as a series of concentration camps (TRC, 2015) or \u201cboarding schools\u201dused to house Indigenous children. Unlawful and immoral acts perpetuated in the IRSs have been termed &#8220;cultural genocide&#8221; at the international level (TRC, 2015; United Nations Declaration on the Rights of Indigenous Peoples [UNDRIP], 2007).<\/p>\n<h5>Impact on Attachment<\/h5>\n<p>From 1876 until the last school closed in 1996, the Canadian federal government physically forced hundreds of thousands of Indigenous children (as young as 4-years-old from their homes and communities, into IRSs (TRC, 2015). Indigenous parents, caregivers and\/or family members who showed verbal or physical restraint relative to the police-enforced taking of Indigenous children to IRSs, were often jailed or shot and killed (Bombay et al., 2014ab; Facing History and Ourselves, 2021; TRC, 2015). Once Indigenous children arrived at the schools, many children were stripped, shaved, and had their skin dyed lighter by IRS staff (Smith, n.d.; TRC, 2015). Students were then assigned numbers (used by staff in place of birth names), were separated from their siblings, and told that if they spoke their Indigenous language (the only language most children knew), there would be severe consequences (TRC, 2015). While it is expected that temporary separations from loved ones (e.g., parents) under tense conditions increased the risk of health issues later in life (R\u00e4ikk\u00f6nen et al., 2011), extended separations under tense conditions are expected to have increased Survivor risk of depressive symptoms and\/or disorders (Bohman et al., 2017; Coffino, 2009) and anxiety symptoms and\/or disorders (Bryant et al., 2017; L\u00e4hdepuro et al., 2019).<\/p>\n<h5>Intergenerational Impacts<\/h5>\n<p>Federal, institutional and academic inquiries into the IRS system continue to highlight various atrocities experienced by many IRS Survivors such as spiritual, verbal, emotional, physical and sexual assault, abuse and violence (TRC, 2015). Trauma of this magnitude continues to impact not only the Survivors, but their children, grandchildren, and other relatives (Bombay et al., 2014ab). This phenomenon, known as <strong>intergenerational trauma<\/strong>, has direct and indirect impacts on various generations of Indigenous populations (Bombay et al., 2014ab; Lehrner &amp; Yehuda, 2018). For example, Indigenous children of IRS Survivors are more likely to have poor psychological health because of the IRS impacts on their parents\u2019 psychosocial functioning and health (Bombay et al., 2011; 2014ab; 2018; Elias et al., 2012; Kaspar, 2014).<\/p>\n<h5>Biopsychosocial Framework<\/h5>\n<p>In general, a Biopsychosocial Framework has been characterised by the ways biological, psychological, and social factors can affect an individual and helps health practitioners conceptualize manifestation of particular physical or mental health issues (Karunamuni et al., 2020). With this framework, it is not hard to understand that while many IRSs delivered\/had poor curriculum, instruction, staffing, and high levels of racism (Barnes &amp; Josefowitz, 2019; TRC, 2015), many Survivors were academically ill-equipped (e.g., lacked adequate language proficiency; Barnes et al., 2006) and oftentimes extremely poorly prepared for adult employment (Miller, 1996; TRC, 2015). It is expected that the cumulative trauma experienced at the IRSs lead to many Survivors struggling with psychosocial well-being\/regulation, connection with other Indigenous socio cultural customs, practices and peoples, and physical and mental health difficulties (Barnes et al., 2019; Ogle et al., 2013; Miller, 1996; TRC, 2015; Vachon et al., 2015).<\/p>\n<h5>Cumulative Risk<\/h5>\n<p>Cumulative risk can be understood as the number and severity of adversities (e.g., low SES, addict parent or caregiver) experienced in childhood, wherein a greater number and severity of adversities often \u201cadds\u201d to a greater risk of an individual to experience later physical and mental health issues (Boles, 2021; Kwong &amp; Hayes, 2017; Felitti &amp; Anda, 2009; Felitti et al., 1998). Putting this research into context, IRS Survivors who underwent separation from parents, and experienced abuse, racism, and forced immersion in a hostile non-Indigenous culture, were all factors that had a cumulative impact and amplified adverse effects of their adverse experiences at IRS (McQuaid et al., 2017; Richmond et al., 2009). As many Indigenous peoples were directly or indirectly affected by IRSs and colonization, in combination with deficient health resources\/geographical isolation, and other ongoing inequities, it is not surprising that many health inequities faced by Indigenous peoples documented 20 years ago, are still faced today (Gracey &amp; King, 2009; RCAP, 1996; TRC, 2015).<\/p>\n<h5>Cultural Resilience<\/h5>\n<p>While Indigenous peoples in Canada continue to face premeditated colonial assimilation tactics, such as the child welfare crisis or &#8220;modern day IRS system&#8221; (Ma et al., 2019; McMillan, 2021; Mitchell, 2019), resilience among Indigenous populations in Canada continues to be researched (Bombay et al., 2010; 2011; Paul et al., 2022). To date, various facets of cultural identity among Indigenous populations in Canada have shown to be protective of the negative effects of colonization, such as cultural community belonging (Bombay et al., 2014ab; First Nations Health Authority, 2019; Paul et al., 2022). While Indigenous culture has been suggested to be protective and stabilize and\/or heighten various aspects of health and wellbeing (e.g., Paul et al., 2022), continued research is needed to better understand how these cultural facets can be implemented in culturally-appropriate care models for Indigenous populations.<\/p>\n<p>To learn more about Indian Residential Schools, visit:\u00a0<a href=\"https:\/\/www.youtube.com\/watch?v=2zuRQmwaREY\">https:\/\/www.youtube.com\/watch?v=2zuRQmwaREY<\/a><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n<\/div>\n<\/section>\n<\/section>\n","protected":false},"author":14,"menu_order":4,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"part":35,"_links":{"self":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters\/571"}],"collection":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/users\/14"}],"version-history":[{"count":42,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters\/571\/revisions"}],"predecessor-version":[{"id":2230,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters\/571\/revisions\/2230"}],"part":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/parts\/35"}],"metadata":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters\/571\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/media?parent=571"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapter-type?post=571"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/contributor?post=571"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/license?post=571"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}