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?