Chapter 10 Human Development Developmental Psychology Study of how behavior changes over the lifespan Challenges to the Developmental Approach Post hoc fallacy false assumption that if one event happens before another it will cause the later o Does A really cause B Bidirectional influences o Developmental Experiences o Ex Teen girls that mature physically quicker tend to associate themselves w older boys may become self conscious etc Ultimately might become sexually active start drinking quicker etc Cohort effects o Idea that people live in one time period differ in experience from those in another time period o It may look like people become more conservative overtime w gender roles but it s really b c they grew up in a time period that was more conservative Research Designs Cross sectional examines people of different ages at a single point in time o Cohort effects might play a role Longitudinal examines development in the same group of people on multiple occasions over time o LONG period of time SAME group Tricky to keep track of same group The Nature Nurture Debate Both play large roles in shaping development It s not an either or issue any longer Gene environment interaction o Impact of genes on behavior depends on the environment where behavior develops Someone with schizophrenia may have had a genetic predisposition that was triggered by traumatic event Nature via nurture o Children with certain genetic predispositions often seek out and create their own environments Gene expression activation or deactivation of genes by environmental experiences throughout development Physical and Motor Development Conception Prenatal Development Most dramatic changes occur during early prenatal development A zygote is formed when sperm cell fertilizes an egg After this three stages of development occur Stages of Physical Development 1 Germinal period a From conception to implantation in uterine wall 0 2 weeks b Zygote divides and doubles forming a blastocyst 2 Embryonic period a From implantation 2 8 weeks b Sexual differentiation begins XX or XY c Limbs facial features major organs begin development 3 Fetal period a 9 weeks to birth b Heart begins to beat Brain Development Between day 18 and the 6th month neurons grow at an incredible rate Up to 250 000 neurons per minute at times Obstacles to Development Teratogens are environmental factors that can exert a negative impact on prenatal development o Examples are smoking drugs chicken pox Alcohol consumption can lead to fetal alcohol syndrome Genetic disruptions can be from disorders or random errors in cell division Prematurity being born prior to 36 weeks can result in numerous problems The less time in utero the greater change of serious complications Motor Development Infants are born with a large set of automatic motor behaviors reflexes o Sucking and rooting reflexes Motor behaviors are bodily motions that occur as result of self initiated force that moves the bones and muscles Wide range in the rate and manner in which children achieve motor milestones Influenced by physical maturity as well as cultural and parenting practices But they are always achieved in the same developmental sequence Physical Development in Childhood The relative size of our body parts changes dramatically during first 20 years Adolescence Transitional period between childhood and adulthood commonly associated with the teenage years This is when our bodies reach full maturity in part due to hormonal release o Estrogens and androgens Attainment of puberty is largely due to that hormonal release Causes changes in primary and secondary sex characteristics o Menarche and spermarche Genetic and environmental influence timing of puberty Physical Development in Adults Most of us reach our physical peaks in early 20s o Strength coordination speed of cognitive processing and physical flexibility Declines begin shortly after including muscle sensory processes and fertility Menopause signals the end of a female s reproductive ability Theories of Cognitive Development Numerous explanations of how we acquire the ability to learn think communicate and remember over time Differ in three ways o Stagelike vs gradual changes in understanding o Domain general vs domain specific o Principal source of learning Ex Experience social interaction biological maturation Jean Piaget 1896 1980 Swiss psychologist who presented 1st complete account of cognitive development Stage theorist Children are not little adults End point of cognitive development logical reasoning Believed children have schemas about how the world works o Schema mental model of the word we have stored in memory organizes experiences Horse vs cow confusion readjusted schema knows difference Piaget s Theory Children use assimilation to acquire new knowledge within a stage When one can no longer assimilate new information accommodation forces change between stages Another example what shape is the earth Piaget s Stages Four stages each with a specific way of looking at the world and cognitive limitations Sensorimotor birth 2 years o Knowledge comes from senses and physical experiences o Focus on the here and now o Lack object permanence and deferred imitation o Major milestone is mental representation Preoperational stage 2 7 years o Marked by an ability to construct mental representations of experience o Hampered by egocentrism and inability to perform mental operations Egocentrism an inability to see the world from others point of view o Also characterized by lack of conservation tasks requiring children to understand that despite a transformation in the physical presentation of an amount the amount remains the same Concrete operations 7 11 years o Can perform mental operations but only for actual physical events Formal operations 11 adulthood o Can understand hypothetical reasoning beyond the here and now F grounded o Also logical concepts and abstract questions meaning of life Pros and Cons of Piaget Inaccurate in a number of ways o Development is more continuous o Probably underestimated children s competence o Culturally biased methods Still highly influential and helped change how we think about cognitive development o Children think differently than adults o Children are active not passive learners Lev Vygotsky 1896 1936 Theory focused on social and cultural influences on cognitive development Parents structure environments for learning and then gradually removing it scaffolding Zone of proximal development