For unlimited access to Textbook Notes, a Class+ subscription is required.
CHAPTER 4 REVIEW: Nature, Nurture, and Human Diversity
Behavior Genetics: Predicting Individual Differences
1: What are genes, and how do behavior geneticists explain our individual
- Chromosomes are coils of DNA containing gene segments that, when ―turned on‖
(expressed), code for the proteins that form our body’s building blocks. Most
human traits are influenced by many genes acting together. Behavior geneticists
seek to quantify genetic and environmental influences on our traits. Studies of
identical twins, fraternal twins, and adoptive families help specify the influence of
genetic nature and of environmental nurture, and the interaction between them
(meaning that the effect of each depends on the other). The stability of
temperament suggests a genetic predisposition.
2: What is heritability, and how does it relate to individuals and groups?
- Heritability describes the extent to which variation among members of a group
can be attributed to genes. Heritable individual differences in traits such as height
or intelligence need not explain group differences. Genes mostly explain why
some are taller than others, but not why people today are taller than a century ago.
3: What is the promise of molecular genetics research?
- Molecular geneticists study the molecular structure and function of genes.
Psychologists and molecular geneticists are cooperating to identify specific
genes—or more often, teams of genes—that put people at risk for disorders.
Evolutionary Psychology: Understanding Human Nature
4: How do evolutionary psychologists use natural selection to explain behavior
- Evolutionary psychologists seek to understand how natural selection has shaped
our traits and behavior tendencies. The principle of natural selection states that
variations increasing the odds of reproducing and surviving are most likely to be
passed on to future generations. Some variations arise from mutations (random
errors in gene replication), others from new gene combinations at conception.
Charles Darwin, whose theory of evolution has for a long time been an organizing
principle in biology, anticipated the contemporary application of evolutionary
principles in psychology.
5: How might an evolutionary psychologist explain gender differences in mating
- Men more than women approve of casual sex, think about sex, and misinterpret
friendliness as sexual interest. Women more than men cite affection as a reason
for first intercourse and have a relational view of sexual activity. Applying
principles of natural selection, evolutionary psychologists reason that men’s
attraction to multiple healthy, fertile-appearing partners increases their chances of
spreading their genes widely. Because women incubate and nurse babies, they
increase their own and their children’s chances of survival by searching for mates