Download Heredity, Environment, and Evolution

Heredity, Environment,
and Evolution
Mod 14 and 15
Influences
 Nature vs Nurture
 Intelligence
 Aggression
 Personality
 Behavioral genetics
 Integrates the influences of heredity, environment and
evolution in terms of their effect on human behavior
Heredity
 How the traits of parents are transmitted biologically to
their offspring
 Chromosomes
 Nucleus of each human cell contains 46 chromos
 23 from each parent
 Genes
 Biochemical units of heredity that make up chromosomes
 Contain DNA (chainlike molecule)
Environment
 Nature vs Nurture debate
 Nature – genetic or biological
 Sets the possibilities for behavior
 Nurture – environmental factors
 Determines how the possibilities will be realized
 Most agree both contribute to influence behavior
Evolution
 Darwin
 gradual change in genes
over time because traits that
allowed our ancestors to
survive where passed on
Twin Studies
 Heritability
 Proportion of variation
among individuals that we
can attribute to genes
 Varies depending on pop.
And envir. being studied
 It is an estimate
 Applies only to the
population as a whole
 Not to individuals
 Numerical value 0 to 1
 Heritability
 Trait with high levels of
heritability is height
 If a given population has
good health and nutrition,
most differences regarding
height will be due to
differences in their genes
 video
Twin Studies
 Monozygotic Twins
 Identical
 100% same genes
 Dizygotic Twins
 Fraternal
 50% same genes
 Thomas Bouchard
 Famous Minnesota Twin
Studies
 Jim Twins Video
Adoption Studies
 Genetic relatives
 Environmental relatives
 Environment shared by a
family’s children has virtually
no impact on personality
Epigenetics
 Study of environmental
influences on gene
expression that occurs
without DNA change
 video
Evolutionary Psychology
 Video overview