[AP Psychology] Biological Bases of Behavior Part C

Behavior genetics

the study of how genes and environments contribute to differences in behavior

Heredity

the passing of genetic information from parents to offspring

Environment (behavior genetics)

all non-genetic influences, including prenatal conditions, family, peers, and surroundings

Nature vs nurture

the question of how much behavior reflects inherited influences versus environmental experience

Chromosomes

threadlike structures made of DNA that contain genes

DNA (deoxyribonucleic acid)

the molecule that carries hereditary genetic information

Genes

segments of DNA that provide instructions for making functional products such as proteins

Gene expression

the process by which a gene is active and its information is used to make a functional product

Inactive gene

a gene not currently being expressed in a particular cell or condition

Genome

all of an organism's genetic material

Identical twins (monozygotic)

twins that develop when one fertilized egg splits, producing two people with nearly identical inherited DNA

Fraternal twins (dizygotic)

twins that develop from two separate fertilized eggs and are genetically similar to ordinary siblings

Identical vs fraternal twins

identical twins originate from one fertilized egg; fraternal twins originate from two

Twin studies

research that compares twins to help estimate genetic and environmental influences on traits

Separated identical twins

identical twins raised apart whose similarities can help researchers investigate hereditary influences

Minnesota separated-twin studies

studies of identical twins raised apart that examined similarities in traits and behavior

Virtual twins

unrelated children of about the same age raised together, used to study shared environmental influences

Adoption studies

research comparing adopted people with biological and adoptive relatives to examine genes and environment

Genetic relatives

biologically related family members who share some inherited DNA

Environmental relatives

family members who share a home or upbringing but are not necessarily genetically related

Heritability

a statistical measure that estimates how much of the variation in a trait within a specific population is due to genetic differences rather than environmental factors

Heritability - key limitation

a population statistic about differences among people, not the percentage of one person's trait caused by genes

Gene-environment interaction

when the effect of genes depends on the environment or the effect of the environment depends on genes

Evolutionary psychology

the study of behavior and mental processes using ideas from evolution and natural selection

Natural selection

the process by which inherited variations that support survival and reproduction tend to become more common over generations

Mutation

a change in genetic information that can create a new inherited variation

Adaptation (evolution)

an inherited characteristic favored across generations because it helped reproduction or survival in an ancestral environment

Evolutionary fitness

reproductive success, or how well an organism passes genes to future generations

Evolutionary explanation of shared behaviors

some behavioral tendencies may appear across cultures because they were useful to human ancestors

Evolutionary mismatch

a once-useful inherited tendency that may be less helpful or harmful in a modern environment

Evolutionary psychology and mating preferences

the hypothesis that some partner preferences may have been shaped by ancestral reproductive pressures

Nature and nurture - modern conclusion

genetic influences and environmental experiences work together rather than acting as completely separate causes