Prenatal Development and the Newborn

�     At 8 weeks after conception, babies are anatomically indistinguishable; 4/5th month different

�     Sex determined by 23rd pair of chromosome

�     X chromosome: comes from either mother or father; females have two, males have one

�     Y chromosome: comes from father, paired with x to form male

�     Y chromosome stimulates development of male sex organ by producing testosterone: most important male sex hormone, but females have it too

�     Gender: biologically or socially influenced characteristics which people define as male/female

�     zygotes: fertilized eggs; less than half survive pass 2 weeks

�     after 10 days, zygote attach to mother’s uterine wall and forms placenta for nourishment, zygote becomes embryo:

developing human from 2 weeks to second month

�     after two months, looks human, called fetus: developing human from 2 months to birth

�     fetus hears muffled version of mother’s voice and prefers it after birth

�     harm can come when placenta gets teratogens: agents that can harm embryo/fetus during prenatal stage; a mother who is a heroin addict will have a heroin addicted baby

�     newborns are equipped with reflexes ideal to survival

�     rooting reflex: reflex, when touched on cheek, to open mouth and find nipple

�     perceptual abilities continue to develop during first month, can distinguish mother’s odour

Infancy and Childhood

�     maturation: biological growth processes that enable orderly change in behaviour, could be influenced by experiences

�     maturation sets the basic course of development and experience adjust it

�     lack of neuron connections reason why earliest memories rarely earlier than third birthday (experiences help develop neural connections)

�     Rosenzweig and Krech reared some young rats in solitary confinement and others in playground; found those in playground develop thicker and heavier brain cortex

�     For optimum development, early years critical –use it or lose it; but development exists through life as neural tissues changes –experiences nurture nature

�     plasticity: brain ability to reoganize pathways to compensate damage; if laser damaged spot in cat’s eye, brain area receiving input from spot will start responding to stimulation from nearby areas in eye;  brain hardware changes with time –can rewired with new synapses

�     children brains most “plastic” –surplus of neurons

�     when neurons are destroyed, nearby ones may partly compensate by making new connections

�     experience influences motor behaviour

�     experience(nurture) before biological development(nature) has limited effect

Cognitive Development

�     Cognition: mental activities associated with knowing, thinking, & remembering

�     Piaget believed child’s mind develops through series of stages

�     Piaget believed children built schemas: concept or framework that organises and interprets info; mental molds into which we pour our experience

�     assimilate: interpreting new experience in terms of existing schemas; given schema for dog, child may call 4-legged animals doggies

�     to fit new experiences, we accommodate: adapting one’s schemas to incorporate new info; child realises doggies schemas too broad and refines category

Piaget’s 4 stages of Cognitive Development

1.    Sensorimotor Stage (Birth – 2 years old)

�     Infants know world in terms of sensory impressions and motor activities

�     Lack objective permanence: awareness that things continue to exist when not perceived; Baby believes toy only exists when it is starring at it

2.    Preoperational Stage (preschool – 6/7 years old)

�     Child learns to use language, but aren’t able to comprehend mental operations of concrete logic; lacks conservation: principle that quantity remains the same despite changes in shape; water from tall, thin glass poured into wide, flat glass would be the same

�     Children are egocentric: inability to see another’s point of view

3.    Concrete Operational Stage (6/7 – 11 years old)

�     Children gain mental operations that enable logical thinking about concrete events; understands conservation and mathematical transformation (reversing arithmetic operations)

4.    Formal Operational Stage (12 years -life)

�     Reasoning expands from concrete (involving actual experiences) to abstract thinking (involving imagined realities and symbols)

�     Children able to solve hypothetical situations and its consequences

�     researchers believe development more continuous than did Piaget

Social Development

�     infants develop intense bond with those who care for them; prefers familiar faces and voices

�     after object permanence, develop stranger anxiety: fear of strangers commonly displayed after 8 months of age

�     attachment: emotional tie with another person; shown by child seeking closeness to caregiver (those who are comfortable, familiar, and responsive to needs) and distress when seperated

�     psychologists use to believe attachment through need for nourishment, but now consider wrong

�     Harlow’s Monkey Studies: Harry Harlow bred monkeys of which he separates from mothers shortly after birth; in cages were a cheesecloth baby blanket; baby monkeys formed intense attachment to blanket –distressed when taken away; later, Harlow created 2 artificial mothers (“Harlow’s Mothers”), one bare wire cylinder with wooden head, other a cylinder wrapped with terry cloth; when reared with nourishing wire mother and nonnourishing cloth mother, monkeys preferred cloth mother; concluded body contact more important than nourishment

�     Critical period: an optimal period shortly after birth when organism’s exposure to certain stimuli/experience produces proper development; first moving object a duckling sees is mother, then follows only it

�     Developmental psychologists believe humans don’t have precise critical period

�     Imprinting: process by which certain animals form attachment during critical period; humans don’t imprint, but becomes attached to “known”

�     Temperament: person’s characteristic emotional reactivity and intensity;  temperaments endure; ex. easy-going, quiet, placid

�     Heredity predispose human differences; anxious infants have high heart rates and reactive nervous system;  identical twins more likely to have similar temperaments than nonidentical

�     Sensitive, responsive mothers have infants who are securely attached while the opposite (attend only when felt like doing and ignores at other times) have infants who are insecurely attached

�     Anxiety over separation from parents peak at 13 months and gradually declines after

�     Erik Erikson claims securely attached children approach life with sense of basic trust: sense that the world is predictable and trustworthy

�     Deprivation of attachment causes withdraw, fear, and other negative consequences; most abusive parents have been neglected/battered as children

�     Many developmentalists believe quality infant day care doesn’t