{"id":567,"date":"2020-06-10T18:18:32","date_gmt":"2020-06-10T18:18:32","guid":{"rendered":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/?post_type=chapter&#038;p=567"},"modified":"2022-01-04T18:38:58","modified_gmt":"2022-01-04T18:38:58","slug":"what-is-lifespan-development","status":"publish","type":"chapter","link":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/chapter\/what-is-lifespan-development\/","title":{"raw":"What is Lifespan Development?","rendered":"What is Lifespan Development?"},"content":{"raw":"<div id=\"86773\" class=\"ui-has-child-title\"><header>\r\n<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\"><span style=\"color: #ffffff\">Learning Objectives<\/span><\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\"><section>By the end of this section, you will be able to:\r\n<ul>\r\n \t<li>Define and distinguish physical, cognitive and psychosocial domains of development<\/li>\r\n \t<li>Discuss the normative approach to development<\/li>\r\n \t<li>Understand the three major issues in development: continuity and discontinuity, one common course of development or many unique courses of development, and nature versus nurture<\/li>\r\n<\/ul>\r\n<\/section><\/div>\r\n<\/div>\r\n<\/header><\/div>\r\n<blockquote id=\"fs-idp89823344\"><\/blockquote>\r\n<p id=\"fs-idp51239088\">Consider the following questions: To what extent is the adult you are today influenced by the child you once were? To what extent is a child fundamentally different from the adult he grows up to be?<\/p>\r\n<p id=\"fs-idp56548352\">These are the types of questions developmental psychologists try to answer, by studying how humans change and grow from conception through childhood, adolescence, adulthood, and death. They view development as a lifelong process that can be studied scientifically across three developmental domains\u2014physical, cognitive, and psychosocial development.\u00a0<span id=\"term561\">Physical development<\/span>\u00a0involves growth and changes in the body and brain, the senses, motor skills, and health and wellness.\u00a0<span id=\"term562\">Cognitive development<\/span>\u00a0involves learning, attention, memory, language, thinking, reasoning, and creativity.\u00a0<span id=\"term563\">Psychosocial development<\/span>\u00a0involves emotions, personality, and social relationships. We refer to these domains throughout the chapter.<\/p>\r\n\r\n<div id=\"fs-idm78242560\" class=\"psychology connect-the-concepts ui-has-child-title\"><section>\r\n<div class=\"os-note-body\">\r\n<h3 id=\"37214\" class=\"os-subtitle\"><span class=\"os-subtitle-label\">Research Methods in Developmental Psychology<\/span><\/h3>\r\n<strong><a id=\"TTdevresearchdesign\"><\/a>TRICKY TOPIC: DEVELOPMENTAL RESEARCH DESIGN<\/strong>\r\n\r\n[embed]https:\/\/youtu.be\/q6h9e2J73xU[\/embed]\r\n\r\n<section id=\"fs-id1470001\">\r\n<p id=\"fs-id1565745\"><em><span style=\"font-size: 1em\">If the video above does not load, click here:\u00a0<a href=\"https:\/\/youtu.be\/q6h9e2J73xU\">https:\/\/youtu.be\/q6h9e2J73xU<\/a><\/span><strong>\r\n<\/strong><\/em><\/p>\r\n\r\n<\/section><section id=\"fs-id1470001\"><em><span id=\"term70\">For a full transcript of this video, click <a href=\"\/intropsychneuro\/back-matter\/appendix\/#devresearchdesign\">here<\/a>\u00a0<\/span><\/em><\/section>\r\n<p id=\"fs-idm16263856\">You\u2019ve learned about a variety of research methods used by psychologists. Developmental psychologists use many of these approaches in order to better understand how individuals change mentally and physically over time. These methods include naturalistic observations, case studies, surveys, and experiments, among others.<\/p>\r\n<p id=\"fs-idp129543968\">Naturalistic observations involve observing behaviour in its natural context. A developmental psychologist might observe how children behave on a playground, at a daycare centre, or in the child\u2019s own home. While this research approach provides a glimpse into how children behave in their natural settings, researchers have very little control over the types and\/or frequencies of displayed behaviour.<\/p>\r\n<p id=\"fs-idp16402112\">In a case study, developmental psychologists collect a great deal of information from one individual in order to better understand physical and psychological changes over the lifespan. This particular approach is an excellent way to better understand individuals, who are exceptional in some way, but it is especially prone to researcher bias in interpretation, and it is difficult to generalize conclusions to the larger population.<\/p>\r\n<p id=\"fs-idm71082272\">The survey method asks individuals to self-report important information about their thoughts, experiences, and beliefs. This particular method can provide large amounts of information in relatively short amounts of time; however, validity of data collected in this way relies on honest self-reporting, and the data is relatively shallow when compared to the depth of information collected in a case study. An example of comprehensive survey was the research done by Ruth W. Howard. In 1947, she obtained her doctorate by surveying 229 sets of triplets, the most comprehensive research of triplets completed at the time. This pioneering woman was also the first African-American woman to earn a PhD in psychology (American Psychological Association, 2019).<\/p>\r\n<p id=\"fs-idm42735664\">Experiments involve significant control over extraneous variables and manipulation of the independent variable. As such, experimental research allows developmental psychologists to make causal statements about certain variables that are important for the developmental process. Because experimental research must occur in a controlled environment, researchers must be cautious about whether behaviours observed in the laboratory translate to an individual\u2019s natural environment.<\/p>\r\n<p id=\"eip-101\">Later in this chapter, you will learn about several experiments in which toddlers and young children observe scenes or actions so that researchers can determine at what age specific cognitive abilities develop. For example, children may observe a quantity of liquid poured from a short, fat glass into a tall, skinny glass. As the experimenters question the children about what occurred, the subjects\u2019 answers help psychologists understand at what age a child begins to comprehend that the volume of liquid remained the same although the shapes of the containers differs.<\/p>\r\n\r\n<\/div>\r\n<\/section><\/div>\r\n<p id=\"fs-idm16739792\">Across these three domains\u2014physical, cognitive, and psychosocial\u2014the\u00a0<span id=\"term564\">normative approach<\/span>\u00a0to development is also discussed. This approach asks, \u201cWhat is normal development?\u201d In the early decades of the 20th century, normative psychologists studied large numbers of children at various ages to determine norms (i.e., average ages) of when most children reach specific developmental milestones in each of the three domains (Gesell, 1933, 1939, 1940; Gesell &amp; Ilg, 1946; Hall, 1904). Although children develop at slightly different rates, we can use these age-related averages as general guidelines to compare children with same-age peers to determine the approximate ages they should reach specific normative events called\u00a0<span id=\"term565\">developmental milestones<\/span>\u00a0(e.g., crawling, walking, writing, dressing, naming colours, speaking in sentences, and starting puberty).<\/p>\r\n<p id=\"fs-idp42788800\">Not all normative events are universal, meaning they are not experienced by all individuals across all cultures. Bi<span class=\"NormalTextRun SCXW205743281 BCX0\">ological milestones, such as puberty, tend to be universal, but social milestones, such as the age when children begin formal schooling, are not necessarily universal; instead, they affect most individuals in a particular\u202fculture\u202f(Gesell &amp; <\/span><span class=\"NormalTextRun SCXW205743281 BCX0\">Ilg<\/span><span class=\"NormalTextRun SCXW205743281 BCX0\">, 1946).<\/span><\/p>\r\n\r\n<h3 class=\"os-title\"><span style=\"font-size: 1em\">Issues in Developmental Psychology<\/span><\/h3>\r\n<section id=\"fs-idp25257600\">\r\n<p id=\"fs-idp84522480\">There are many different theoretical approaches regarding human development. As we evaluate them in this chapter, recall that developmental psychology focuses on how people change;\u00a0<span class=\"TextRun SCXW57924373 BCX0\" lang=\"EN-US\" xml:lang=\"EN-US\"><span class=\"NormalTextRun ContextualSpellingAndGrammarErrorV2 SCXW57924373 BCX0\">all<\/span><span class=\"NormalTextRun SCXW57924373 BCX0\"> the approaches <\/span><span class=\"NormalTextRun SCXW57924373 BCX0\">presented<\/span><span class=\"NormalTextRun SCXW57924373 BCX0\"> in this chapter address questions of change: Is the change smooth or uneven (continuous versus discontinuous)? Is this pattern of change the same for everyone, or are there many different patterns of change (one course of development versus many courses)? How do genetics and environment interact to influence development (nature versus nurture)?<\/span><\/span><span class=\"EOP SCXW57924373 BCX0\">\u00a0<\/span><\/p>\r\n\r\n<section id=\"fs-idp894160\">\r\n<h4>Is Development Continuous or Discontinuous?<\/h4>\r\n<p id=\"fs-idm18275488\"><span id=\"term567\">Continuous development<\/span>\u00a0views development as a cumulative process, gradually improving on existing skills (<a class=\"autogenerated-content\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-1-what-is-lifespan-development#Figure_09_01_Develop\">Figure LD.2<\/a>). With this type of development, there is gradual change. Consider, for example, a child\u2019s physical growth: adding inches to height year by year. In contrast, theorists who view development as\u00a0<span id=\"term568\">discontinuous<\/span>\u00a0believe that development takes place in unique stages: It occurs at specific times or ages. With this type of development, the change is more sudden, such as an infant\u2019s ability to conceive <strong>object permanence<\/strong> (the idea that even if something is out of sight, it still exists).<\/p>\r\n\r\n<div id=\"Figure_09_01_Develop\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"975\"]<img id=\"86716\" src=\"https:\/\/openstax.org\/resources\/b87dcace24a8bae45e97843cb30c4e49fdcfe900\" alt=\"Continuous and Discontinuous development are shown side by side using two separate pictures. The first picture is a triangle labeled \u201cContinuous Development\u201d which slopes upward from Infancy to Adulthood in a straight line. The second picture is 4 bars side by side labeled \u201cDiscontinuous Development\u201d which get higher from Infancy to Adulthood. These bars resemble a staircase.\" width=\"975\" height=\"266\" \/> Figure LD.2\u00a0The concept of continuous development can be visualized as a smooth slope of progression, whereas discontinuous development sees growth in more discrete stages.[\/caption]<\/figure>\r\n<\/div>\r\n<\/section><section id=\"fs-idm58971488\">\r\n<h4>Is There One Course of Development or Many?<\/h4>\r\n<p id=\"fs-idp30181200\">Is development essentially the same, or universal, for all children (i.e., there is one course of development) or does development follow a different course for each child, depending on the child\u2019s specific genetics and environment (i.e., there are many courses of development)? Do people across the world share more similarities or more differences in their development? How much do culture and genetics influence a child\u2019s behaviour?<\/p>\r\n<p id=\"fs-idp30591696\">Stage theories hold that the sequence of development is universal. For example, in cross-cultural studies of language development, children from around the world reach language milestones in a similar sequence (Gleitman &amp; Newport, 1995). Infants in all cultures coo before they babble. They begin babbling at about the same age and utter their first word around 12 months old. Yet we live in diverse contexts that have a unique effect on each of us. For example, researchers once believed that motor development follows one course for all children regardless of culture. However, child care practices vary by culture, and different practices have been found to\u00a0<span class=\"TextRun SCXW231591995 BCX0\" lang=\"EN-US\" xml:lang=\"EN-US\"><span class=\"NormalTextRun SCXW231591995 BCX0\">a<\/span><span class=\"NormalTextRun SCXW231591995 BCX0\">lter the timing of<\/span><span class=\"NormalTextRun SCXW231591995 BCX0\"> developmental milestones such as sitting, crawling, and walking (<\/span><span class=\"NormalTextRun SCXW231591995 BCX0\">Karasik<\/span><span class=\"NormalTextRun SCXW231591995 BCX0\">, Adolph, <\/span><span class=\"NormalTextRun SCXW231591995 BCX0\">Tamis-<\/span><span class=\"NormalTextRun SpellingErrorV2 SCXW231591995 BCX0\">LeMonda<\/span><span class=\"NormalTextRun SCXW231591995 BCX0\">, &amp; Bornstein, 2010).<\/span><\/span><span class=\"EOP SCXW231591995 BCX0\">\u00a0<\/span><\/p>\r\n<p id=\"fs-idp2356688\">For instance, let\u2019s look at the Ach\u00e9 society in Paraguay. They spend a significant amount of time foraging in forests. While foraging, Ach\u00e9 mothers carry their young children, rarely putting them down in order to protect them from getting hurt in the forest. Consequently, their children walk much later: They walk around 23\u201325 months old, in comparison to infants in Western cultures who begin to walk around 12 months old. However, as Ach\u00e9 children become older, they are allowed more freedom to move about, and by about age 9, their motor skills surpass those of U.S. children of the same age: Ach\u00e9 children are able to climb trees up to 25 feet tall and use machetes to chop their way through the forest (Kaplan &amp; Dove, 1987). So,\u00a0<span class=\"NormalTextRun BCX0 SCXW148254255\">development <\/span><span class=\"NormalTextRun BCX0 SCXW148254255\">can be<\/span><span class=\"NormalTextRun BCX0 SCXW148254255\"> influenced by <\/span><span class=\"NormalTextRun BCX0 SCXW148254255\">different<\/span><span class=\"NormalTextRun BCX0 SCXW148254255\"> contexts, <\/span><span class=\"NormalTextRun BCX0 SCXW148254255\">but the<\/span><span class=\"NormalTextRun BCX0 SCXW148254255\"> functions themselves are present in all societies <\/span>(<a class=\"autogenerated-content\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-1-what-is-lifespan-development#Figure_09_01_Play\">Figure LD.3<\/a>).<\/p>\r\n\r\n<div id=\"Figure_09_01_Play\" class=\"os-figure\">\r\n<figure>\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"649\"]<img id=\"54969\" src=\"https:\/\/openstax.org\/resources\/be10baf5c238991e590cf9d7e3f4ccf6d2f0bf48\" alt=\"Photograph A shows two children wearing inner tubes playing in the shallow water at the beach. Photograph B shows two children playing in the sand at a beach.\" width=\"649\" height=\"238\" \/> Figure LD.3\u00a0All children across the world love to play. Whether in (a) Florida or (b) South Africa, children enjoy exploring sand, sunshine, and the sea. (credit a: modification of work by \u201cVisit St. Pete\/Clearwater\u201d\/Flickr; credit b: modification of work by \"stringer_bel\"\/Flickr)[\/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\">How Do Nature and Nurture Influence Development?<\/span><\/div>\r\n<\/div>\r\n<\/section><section id=\"fs-idm78676480\">\r\n<p id=\"fs-idp6948224\"><span class=\"TextRun SCXW17699109 BCX0\" lang=\"EN-US\" xml:lang=\"EN-US\"><span class=\"NormalTextRun SCXW17699109 BCX0\">To what extent do nature\u202f(biology and genetics) and\u202fnurture\u202f(environment and culture) contribute to development? <\/span><span class=\"NormalTextRun SCXW17699109 BCX0\">We are all born with specific genetic traits inherited from our parents, such as eye <\/span><span class=\"NormalTextRun SpellingErrorV2 SCXW17699109 BCX0\">colour<\/span><span class=\"NormalTextRun SCXW17699109 BCX0\">, height, and certain personality traits. <\/span><span class=\"NormalTextRun SCXW17699109 BCX0\">T<\/span><span class=\"NormalTextRun SCXW17699109 BCX0\">here is a<\/span><span class=\"NormalTextRun SCXW17699109 BCX0\">lso a<\/span><span class=\"NormalTextRun SCXW17699109 BCX0\"> deep interaction between our genes and our environment: Our unique experiences in our environment influence whether and how particular traits are expressed, and at the same time, our genes influence how we interact with our environment (Diamond, 2009; Lobo, 2008). This chapter will show that there is a reciprocal interaction between nature and nurture as they both shape who we become, but the debate continues as to the relative contributions of each.<\/span><\/span><span class=\"EOP SCXW17699109 BCX0\">\u00a0<\/span><\/p>\r\n\r\n<\/section><\/section>","rendered":"<div id=\"86773\" class=\"ui-has-child-title\">\n<header>\n<div class=\"textbox textbox--learning-objectives\"><\/div>\n<\/header>\n<header class=\"textbox__header\">\n<p class=\"textbox__title\"><span style=\"color: #ffffff\">Learning Objectives<\/span><\/p>\n<\/header>\n<div class=\"textbox__content\">\n<section>By the end of this section, you will be able to:<\/p>\n<ul>\n<li>Define and distinguish physical, cognitive and psychosocial domains of development<\/li>\n<li>Discuss the normative approach to development<\/li>\n<li>Understand the three major issues in development: continuity and discontinuity, one common course of development or many unique courses of development, and nature versus nurture<\/li>\n<\/ul>\n<\/section>\n<\/div>\n<\/div>\n<blockquote id=\"fs-idp89823344\"><\/blockquote>\n<p id=\"fs-idp51239088\">Consider the following questions: To what extent is the adult you are today influenced by the child you once were? To what extent is a child fundamentally different from the adult he grows up to be?<\/p>\n<p id=\"fs-idp56548352\">These are the types of questions developmental psychologists try to answer, by studying how humans change and grow from conception through childhood, adolescence, adulthood, and death. They view development as a lifelong process that can be studied scientifically across three developmental domains\u2014physical, cognitive, and psychosocial development.\u00a0<span id=\"term561\">Physical development<\/span>\u00a0involves growth and changes in the body and brain, the senses, motor skills, and health and wellness.\u00a0<span id=\"term562\">Cognitive development<\/span>\u00a0involves learning, attention, memory, language, thinking, reasoning, and creativity.\u00a0<span id=\"term563\">Psychosocial development<\/span>\u00a0involves emotions, personality, and social relationships. We refer to these domains throughout the chapter.<\/p>\n<div id=\"fs-idm78242560\" class=\"psychology connect-the-concepts ui-has-child-title\">\n<section>\n<div class=\"os-note-body\">\n<h3 id=\"37214\" class=\"os-subtitle\"><span class=\"os-subtitle-label\">Research Methods in Developmental Psychology<\/span><\/h3>\n<p><strong><a id=\"TTdevresearchdesign\"><\/a>TRICKY TOPIC: DEVELOPMENTAL RESEARCH DESIGN<\/strong><\/p>\n<p><iframe loading=\"lazy\" id=\"oembed-1\" title=\"Tricky Topics: Developmental Research Designs\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/q6h9e2J73xU?feature=oembed&#38;rel=0\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<section id=\"fs-id1470001\">\n<p id=\"fs-id1565745\"><em><span style=\"font-size: 1em\">If the video above does not load, click here:\u00a0<a href=\"https:\/\/youtu.be\/q6h9e2J73xU\">https:\/\/youtu.be\/q6h9e2J73xU<\/a><\/span><strong><br \/>\n<\/strong><\/em><\/p>\n<\/section>\n<section><em><span id=\"term70\">For a full transcript of this video, click <a href=\"\/intropsychneuro\/back-matter\/appendix\/#devresearchdesign\">here<\/a>\u00a0<\/span><\/em><\/section>\n<p id=\"fs-idm16263856\">You\u2019ve learned about a variety of research methods used by psychologists. Developmental psychologists use many of these approaches in order to better understand how individuals change mentally and physically over time. These methods include naturalistic observations, case studies, surveys, and experiments, among others.<\/p>\n<p id=\"fs-idp129543968\">Naturalistic observations involve observing behaviour in its natural context. A developmental psychologist might observe how children behave on a playground, at a daycare centre, or in the child\u2019s own home. While this research approach provides a glimpse into how children behave in their natural settings, researchers have very little control over the types and\/or frequencies of displayed behaviour.<\/p>\n<p id=\"fs-idp16402112\">In a case study, developmental psychologists collect a great deal of information from one individual in order to better understand physical and psychological changes over the lifespan. This particular approach is an excellent way to better understand individuals, who are exceptional in some way, but it is especially prone to researcher bias in interpretation, and it is difficult to generalize conclusions to the larger population.<\/p>\n<p id=\"fs-idm71082272\">The survey method asks individuals to self-report important information about their thoughts, experiences, and beliefs. This particular method can provide large amounts of information in relatively short amounts of time; however, validity of data collected in this way relies on honest self-reporting, and the data is relatively shallow when compared to the depth of information collected in a case study. An example of comprehensive survey was the research done by Ruth W. Howard. In 1947, she obtained her doctorate by surveying 229 sets of triplets, the most comprehensive research of triplets completed at the time. This pioneering woman was also the first African-American woman to earn a PhD in psychology (American Psychological Association, 2019).<\/p>\n<p id=\"fs-idm42735664\">Experiments involve significant control over extraneous variables and manipulation of the independent variable. As such, experimental research allows developmental psychologists to make causal statements about certain variables that are important for the developmental process. Because experimental research must occur in a controlled environment, researchers must be cautious about whether behaviours observed in the laboratory translate to an individual\u2019s natural environment.<\/p>\n<p id=\"eip-101\">Later in this chapter, you will learn about several experiments in which toddlers and young children observe scenes or actions so that researchers can determine at what age specific cognitive abilities develop. For example, children may observe a quantity of liquid poured from a short, fat glass into a tall, skinny glass. As the experimenters question the children about what occurred, the subjects\u2019 answers help psychologists understand at what age a child begins to comprehend that the volume of liquid remained the same although the shapes of the containers differs.<\/p>\n<\/div>\n<\/section>\n<\/div>\n<p id=\"fs-idm16739792\">Across these three domains\u2014physical, cognitive, and psychosocial\u2014the\u00a0<span id=\"term564\">normative approach<\/span>\u00a0to development is also discussed. This approach asks, \u201cWhat is normal development?\u201d In the early decades of the 20th century, normative psychologists studied large numbers of children at various ages to determine norms (i.e., average ages) of when most children reach specific developmental milestones in each of the three domains (Gesell, 1933, 1939, 1940; Gesell &amp; Ilg, 1946; Hall, 1904). Although children develop at slightly different rates, we can use these age-related averages as general guidelines to compare children with same-age peers to determine the approximate ages they should reach specific normative events called\u00a0<span id=\"term565\">developmental milestones<\/span>\u00a0(e.g., crawling, walking, writing, dressing, naming colours, speaking in sentences, and starting puberty).<\/p>\n<p id=\"fs-idp42788800\">Not all normative events are universal, meaning they are not experienced by all individuals across all cultures. Bi<span class=\"NormalTextRun SCXW205743281 BCX0\">ological milestones, such as puberty, tend to be universal, but social milestones, such as the age when children begin formal schooling, are not necessarily universal; instead, they affect most individuals in a particular\u202fculture\u202f(Gesell &amp; <\/span><span class=\"NormalTextRun SCXW205743281 BCX0\">Ilg<\/span><span class=\"NormalTextRun SCXW205743281 BCX0\">, 1946).<\/span><\/p>\n<h3 class=\"os-title\"><span style=\"font-size: 1em\">Issues in Developmental Psychology<\/span><\/h3>\n<section id=\"fs-idp25257600\">\n<p id=\"fs-idp84522480\">There are many different theoretical approaches regarding human development. As we evaluate them in this chapter, recall that developmental psychology focuses on how people change;\u00a0<span class=\"TextRun SCXW57924373 BCX0\" lang=\"EN-US\" xml:lang=\"EN-US\"><span class=\"NormalTextRun ContextualSpellingAndGrammarErrorV2 SCXW57924373 BCX0\">all<\/span><span class=\"NormalTextRun SCXW57924373 BCX0\"> the approaches <\/span><span class=\"NormalTextRun SCXW57924373 BCX0\">presented<\/span><span class=\"NormalTextRun SCXW57924373 BCX0\"> in this chapter address questions of change: Is the change smooth or uneven (continuous versus discontinuous)? Is this pattern of change the same for everyone, or are there many different patterns of change (one course of development versus many courses)? How do genetics and environment interact to influence development (nature versus nurture)?<\/span><\/span><span class=\"EOP SCXW57924373 BCX0\">\u00a0<\/span><\/p>\n<section id=\"fs-idp894160\">\n<h4>Is Development Continuous or Discontinuous?<\/h4>\n<p id=\"fs-idm18275488\"><span id=\"term567\">Continuous development<\/span>\u00a0views development as a cumulative process, gradually improving on existing skills (<a class=\"autogenerated-content\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-1-what-is-lifespan-development#Figure_09_01_Develop\">Figure LD.2<\/a>). With this type of development, there is gradual change. Consider, for example, a child\u2019s physical growth: adding inches to height year by year. In contrast, theorists who view development as\u00a0<span id=\"term568\">discontinuous<\/span>\u00a0believe that development takes place in unique stages: It occurs at specific times or ages. With this type of development, the change is more sudden, such as an infant\u2019s ability to conceive <strong>object permanence<\/strong> (the idea that even if something is out of sight, it still exists).<\/p>\n<div id=\"Figure_09_01_Develop\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 975px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"86716\" src=\"https:\/\/openstax.org\/resources\/b87dcace24a8bae45e97843cb30c4e49fdcfe900\" alt=\"Continuous and Discontinuous development are shown side by side using two separate pictures. The first picture is a triangle labeled \u201cContinuous Development\u201d which slopes upward from Infancy to Adulthood in a straight line. The second picture is 4 bars side by side labeled \u201cDiscontinuous Development\u201d which get higher from Infancy to Adulthood. These bars resemble a staircase.\" width=\"975\" height=\"266\" \/><figcaption class=\"wp-caption-text\">Figure LD.2\u00a0The concept of continuous development can be visualized as a smooth slope of progression, whereas discontinuous development sees growth in more discrete stages.<\/figcaption><\/figure>\n<\/figure>\n<\/div>\n<\/section>\n<section id=\"fs-idm58971488\">\n<h4>Is There One Course of Development or Many?<\/h4>\n<p id=\"fs-idp30181200\">Is development essentially the same, or universal, for all children (i.e., there is one course of development) or does development follow a different course for each child, depending on the child\u2019s specific genetics and environment (i.e., there are many courses of development)? Do people across the world share more similarities or more differences in their development? How much do culture and genetics influence a child\u2019s behaviour?<\/p>\n<p id=\"fs-idp30591696\">Stage theories hold that the sequence of development is universal. For example, in cross-cultural studies of language development, children from around the world reach language milestones in a similar sequence (Gleitman &amp; Newport, 1995). Infants in all cultures coo before they babble. They begin babbling at about the same age and utter their first word around 12 months old. Yet we live in diverse contexts that have a unique effect on each of us. For example, researchers once believed that motor development follows one course for all children regardless of culture. However, child care practices vary by culture, and different practices have been found to\u00a0<span class=\"TextRun SCXW231591995 BCX0\" lang=\"EN-US\" xml:lang=\"EN-US\"><span class=\"NormalTextRun SCXW231591995 BCX0\">a<\/span><span class=\"NormalTextRun SCXW231591995 BCX0\">lter the timing of<\/span><span class=\"NormalTextRun SCXW231591995 BCX0\"> developmental milestones such as sitting, crawling, and walking (<\/span><span class=\"NormalTextRun SCXW231591995 BCX0\">Karasik<\/span><span class=\"NormalTextRun SCXW231591995 BCX0\">, Adolph, <\/span><span class=\"NormalTextRun SCXW231591995 BCX0\">Tamis-<\/span><span class=\"NormalTextRun SpellingErrorV2 SCXW231591995 BCX0\">LeMonda<\/span><span class=\"NormalTextRun SCXW231591995 BCX0\">, &amp; Bornstein, 2010).<\/span><\/span><span class=\"EOP SCXW231591995 BCX0\">\u00a0<\/span><\/p>\n<p id=\"fs-idp2356688\">For instance, let\u2019s look at the Ach\u00e9 society in Paraguay. They spend a significant amount of time foraging in forests. While foraging, Ach\u00e9 mothers carry their young children, rarely putting them down in order to protect them from getting hurt in the forest. Consequently, their children walk much later: They walk around 23\u201325 months old, in comparison to infants in Western cultures who begin to walk around 12 months old. However, as Ach\u00e9 children become older, they are allowed more freedom to move about, and by about age 9, their motor skills surpass those of U.S. children of the same age: Ach\u00e9 children are able to climb trees up to 25 feet tall and use machetes to chop their way through the forest (Kaplan &amp; Dove, 1987). So,\u00a0<span class=\"NormalTextRun BCX0 SCXW148254255\">development <\/span><span class=\"NormalTextRun BCX0 SCXW148254255\">can be<\/span><span class=\"NormalTextRun BCX0 SCXW148254255\"> influenced by <\/span><span class=\"NormalTextRun BCX0 SCXW148254255\">different<\/span><span class=\"NormalTextRun BCX0 SCXW148254255\"> contexts, <\/span><span class=\"NormalTextRun BCX0 SCXW148254255\">but the<\/span><span class=\"NormalTextRun BCX0 SCXW148254255\"> functions themselves are present in all societies <\/span>(<a class=\"autogenerated-content\" href=\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/9-1-what-is-lifespan-development#Figure_09_01_Play\">Figure LD.3<\/a>).<\/p>\n<div id=\"Figure_09_01_Play\" class=\"os-figure\">\n<figure>\n<figure style=\"width: 649px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"54969\" src=\"https:\/\/openstax.org\/resources\/be10baf5c238991e590cf9d7e3f4ccf6d2f0bf48\" alt=\"Photograph A shows two children wearing inner tubes playing in the shallow water at the beach. Photograph B shows two children playing in the sand at a beach.\" width=\"649\" height=\"238\" \/><figcaption class=\"wp-caption-text\">Figure LD.3\u00a0All children across the world love to play. Whether in (a) Florida or (b) South Africa, children enjoy exploring sand, sunshine, and the sea. (credit a: modification of work by \u201cVisit St. Pete\/Clearwater\u201d\/Flickr; credit b: modification of work by &#8220;stringer_bel&#8221;\/Flickr)<\/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\">How Do Nature and Nurture Influence Development?<\/span><\/div>\n<\/div>\n<\/section>\n<section id=\"fs-idm78676480\">\n<p id=\"fs-idp6948224\"><span class=\"TextRun SCXW17699109 BCX0\" lang=\"EN-US\" xml:lang=\"EN-US\"><span class=\"NormalTextRun SCXW17699109 BCX0\">To what extent do nature\u202f(biology and genetics) and\u202fnurture\u202f(environment and culture) contribute to development? <\/span><span class=\"NormalTextRun SCXW17699109 BCX0\">We are all born with specific genetic traits inherited from our parents, such as eye <\/span><span class=\"NormalTextRun SpellingErrorV2 SCXW17699109 BCX0\">colour<\/span><span class=\"NormalTextRun SCXW17699109 BCX0\">, height, and certain personality traits. <\/span><span class=\"NormalTextRun SCXW17699109 BCX0\">T<\/span><span class=\"NormalTextRun SCXW17699109 BCX0\">here is a<\/span><span class=\"NormalTextRun SCXW17699109 BCX0\">lso a<\/span><span class=\"NormalTextRun SCXW17699109 BCX0\"> deep interaction between our genes and our environment: Our unique experiences in our environment influence whether and how particular traits are expressed, and at the same time, our genes influence how we interact with our environment (Diamond, 2009; Lobo, 2008). This chapter will show that there is a reciprocal interaction between nature and nurture as they both shape who we become, but the debate continues as to the relative contributions of each.<\/span><\/span><span class=\"EOP SCXW17699109 BCX0\">\u00a0<\/span><\/p>\n<\/section>\n<\/section>\n","protected":false},"author":14,"menu_order":2,"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\/567"}],"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":24,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters\/567\/revisions"}],"predecessor-version":[{"id":2225,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapters\/567\/revisions\/2225"}],"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\/567\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/media?parent=567"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/pressbooks\/v2\/chapter-type?post=567"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/contributor?post=567"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/digitaleditions.library.dal.ca\/intropsychneuro\/wp-json\/wp\/v2\/license?post=567"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}