Chapter 3 Flashcards
(29 cards)
applies evolutionary theory to explain human behavior
Evolutionary psychology
“inheriting” a shared environment
cultural evolution
Sperm cells and ova (eggs): meiosis Cells divide into 4 to produce one ovum or 4 sperm Functional cells have 23 chromosomes Last chromosome determines sex of fetus XX = female, XY = male
How they (sex cells) split
Sperm cell (23 chromosomes) + ovum or egg (23 chromosomes) = zygote (46 chromosomes in 23 pairs)
genetic code
genes and environment interact to determine which genes are activated
gene expression
Genetic material inherited from parents
“the stuff”
Genotype:
Observable bodily characteristics and behavior
“the look”
Phenotype:
rare in humans (tongue rolling)
Characteristic influenced by one pair of genes
Dominant genes will be expressed when paired with a recessive gene
Single gene-pair
Characteristic influenced by multiple pairs of genes
Ex: IQ
Polygenetic (most human characteristics)
Characteristic influenced by genes located on the sex chromosome (most influenced by the X chromosome)
EX: color blindness
Sex-linked
change in the structure/order of a gene
Beneficial or harmful
Likelihood increased by radiation
Mostly random error
Mutation
deleting or duplicating genes
Inherited or spontaneous (ex: egg didn’t divide properly in utero)
Copy Number Variation (CNV):
females with one X chromosome (X) (1 in 2,000 births)
Turner syndrome
male with one or more extra X chromosome (XXY) (may be infertile)
Klinefelter syndrome:
male with extra Y chromosome (taller, stronger than normal)
XYY syndrome
arm of X chromosome is “breaking off,” intellectual disabilities
Fragile X syndrome
blood disease common among people of African descent
Sickle-cell anemia or disease
dominant gene carried
Disrupts nervous system, death in middle age
Screening but no cure
Huntington’s disease
recessive gene pair
Lack enzyme to break down phenylalanine (in most foods)
Acid build up, attacks nervous system
Screening, special diet.
Phenylketonuria (PKU):
help tease out differences in genetics and environment in behavior
Compare identical and fraternal twin pairs raised together or apart
Issues
Prenatal environment
Psychological similarities due to treatment
Twin-study design
Compare children adopted at birth to biological and adoptive parents
Issues: prenatal environment, similarity of homes, above average care in adoptive homes.
Adoption study
Concordance rates for identical twins 52%, fraternal twins 22%
Since concordance isn’t 100%, environment is also a factor
Is sexual orientation heritable?
Intellectual Ability
Identical twins are most similar
Environmental influences (SES)
Temperament/Personality
Shared environment factors not very important
Psychological disorders
Alcohol and substance use disorders, autism spectrum disorder, ADHD, eating disorders, aggression, schizophrenia.
Weight
Adopted children resemble biological parents
What else is heritable?
disorder = predisposition/vulnerability + experience of stress
Diathesis-stress model (tug of war):
