Development
Major Issues
•	Areas of development
•	Life-span development
•	How to conceptualize developmental changes
•	Heredity vs. environment
Areas of Development
•	Cognitive
–	Infancy especially
•	Social/personality
•	Brain development is hot area
•	And aging
•	Developmental disabilities
Life-span development
•	Before 1970 or 1980 
–	Development covered basically ages 2-12
–	Infants were thought to be uninteresting and dumb
–	Adolescents were creepy
–	And adults didn’t change
•	Now the majority of work takes place at the ends
–	Major work on adult development
–	And infants have a lot more tricks than previously thought
Aging
•	People living longer
•	Intellectual and social changes
•	Death and dying
•	Social development and relationships
Developmental Disabilities
•	Examples
–	Autism
–	Williams syndrome
•	Light shed on normal development
Conceptualizing Developmental Changes
•	The traditional blank slate
•	Stages – Piaget
•	Modularization and evolution
The Traditional Approach
•	At birth few skills or cognitive processes
•	Behaviorism
–	Tabula rasa
–	Everything is learned
•	Reinforcement based learning
•	Imitation
•	Development is basically linear
The Stages Approach
•	Many versions
–	Piaget
–	Freud
Piaget’s General Version
•	Development is non-linear
–	Rapid changes at some points
–	And relatively static at others
•	Child has to have mental apparatus to benefit from experience and learn –schema
–	Assimilation
–	Contrast
•	Processing at each stage
–	Has its own integrity – works for the child
–	Yet seems immature
•	Not that the child lacks a few facts and skills
•	But seems to reason differently

Modularization and Evolution
•	In part a reaction to Piaget
•	Children has certain competencies at birth or shortly after
•	May not show up immediately – maturation
–	Walking
–	Speech
Nature vs. Nurture
•	An issue since time of ancient Greeks
•	Until about 1920 most psychologists emphasized heredity
•	Then until recently experience
•	Changes
–	New knowledge about genetics and the genome
–	New research on human infants
–	Evolutionary arguments
Study of Infants
•	Scientist in the crib – Gopnik, et al
•	Infants have
–	Certain skills
–	Proclivities to gain certain sorts of information
•	Areas 
–	Social skills
–	Language
–	Object representation
Some Examples
•	Biology
•	Object constancy
•	Folk psychology
•	Physics
•	Number
Some Examples from Biology
•	Children distinguish animate from inanimate movement
•	Have notion of essences from early age
–	“Insides” vs. “outsides”
–	Understand that flamingos are birds but bats are not
Issues for Development
•	How does the home environment affect children
–	Parental influences
–	Sibling influences
•	Obvious that such effects occur
–	Children similarity to parents is often obvious
–	Plus we know that children often do what their parents wish
Studying This Formally?
•	Usual strategy is to correlate parental behavior with children’s behavior
•	Many examples
–	Spanking and disobedient behavior
–	Age of weaning and oral behaviors
–	Parental style and children’s maturity
–	Parental reading and IQ
–	Parental responsiveness and secure attachment
–	Parental behavior and gender stereotypic behavior
•	Also adoption and twin studies
Problems with Correlations
•	Could children behavior cause parental behavior?
–	Disobedient children get spanked more
–	Children who are mature create parents who are more relaxed and flexible
–	Children who have IQ enjoy being read to more often
–	Children who are securely attached to moms encourage more responsive behavior
–	Children want to do gender stereotypic things and parents find it easier to go with the program
Third Variables
•	Genetic influences
•	Parents create compatible outside home environments
–	Churches
–	Schools
–	Children’s activities which affect friendship patterns
Data
•	Literally millions of correlations
•	But problems
–	Correlates are often quite small
–	Inconsistent from study to study
–	Adoption studies show low to non-existent correlations between adopted sibs in same family
The Harris Argument
•	Judith Rich Harris (1995, 1999)
•	Correlations between parents and children are almost all genetic
•	Environmental influences are almost all peer
–	Even shared environmental influences within the family are largely peer
–	Same schools, same neighborhoods
Example: Genes in the Family -- Reiss
•	High correlation between antisocial behavior by children and punitive parental behavior
•	Passive model – same genes that make child antisocial make parents explosive
•	Child effects evocative – genetic effects on antisocial which influence parental behavior
•	Parental effects evocative – genetic effects on child (not antisocial directly e.g., stubbornness)
–	Influence parent
–	Parental behavior creates antisocial
Heritability Increases over Life Span
•	For IQ genetic effects increase
•	Effects on genes on environment selection
–	Smarter kids select activities that make them smarter
–	Education
•	Genes affect peer groups
–	Kids of different abilities tend to become more isolated
–	“Smart” peer groups encourage academic achievement
–	And less smart ones tend to denigrate academics
Sibling Influences?
•	Weak effects but mostly genetic
–	Almost no sib effects for adopted kids in same family
–	And effects can be accounted for by environment
•	Birth order
–	Weak to non-existent effects for personality
–	Some effects for ability
•	Small for IQ
•	Educational attainment
•	Prestige of occupation
–	Huge stereotypes
•	Within family perceptions
•	Not necessarily extended outside family
Peer Groups
•	Harris argues that in all cultures peer groups do most of the socializing
–	Language spoken – important because not genetic
–	Peer cultures
–	Children obsessed with not being different
•	Peer groups often reflect shared environment
Peer Influence
•	Children do imitate adults
–	But much adult behavior is inappropriate for children
–	Tends to wane by school age
•	But peers are more important
–	Children don’t want to be like adults but like other children
–	So they adopt whatever is “cool” at any point in time
Is Harris Correct?
•	Correct in emphasizing importance of genetics in parent-child similarities
•	Correct in emphasizing the importance of peer effects
•	Probably incorrect in emphasizing the null role of parents
Does Parental Behavior Have Any Impact
•	Inside family but not outside
•	Single episodes
•	Group vs. individual effects
–	Correlations are across individuals
–	Same parental behavior may have opposite effects on different children
•	May be stronger effects for some domains
–	Attitudes?
–	Values?