Nature/nurture Questions

Front 1

What are genes, and how do behavior geneticists explain our individual differences?

Back 1

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.

Front 2

What is heritability, and how does it relate to individuals and groups?

Back 2

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 are taller than a century ago.

Front 3

What is the promise of molecular genetics research?

Back 3

Molecular genetics 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.

Front 4

How do evolutionary psychologists use natural selection to explain behavior tendencies?

Back 4

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.

Front 5

How might an evolutionary psychologist explain gender differences in mating preferences?

Back 5

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 with the resources and the potential for long-term investment in their joint offspring.

Front 6

What are the key criticisms of evolutionary psychology?

Back 6

Critics argue that evolutionary psychologists start with an effect and work backward to an explanation, that the evolutionary perspective gives too little emphasis to social influences, and the evolutionary viewpoint absolves people from taking responsibility for their sexual behavior. Evolutionary psychologists respond that understanding our predispositions can help us overcome them. They also cite the value of testable predictions based on evolutionary principles, as well as the coherence and explanatory power of those principles.

Front 7

To what extent are our lives shaped by early stimulation, by parents, and by peers?

Back 7

During maturation, a child's brain changes as neural connections increase in areas associated with stimulating activity, and unused synapses degenerate. Parents influence their children in areas such as manners and political and religious beliefs, but not in areas, such as personality. Language and other behaviors are shaped by peer groups, as children adjust to fit in. By choosing their children's neighborhoods and schools, parents can exert some influence over peer group culture.

Front 8

How do cultural norms affect our behavior?

Back 8

Cultural norms are rules for accepted and expected behaviors, ideas attitudes, and values. Across places and over time cultures differ in their norms. Despite such cultural variations, we humans share many common forces that influence behavior.

Front 9

How do individualist and collectivist cultural influences affect people?

Back 9

Cultures based on self-reliant individualism, like those of most of the United States, Canada, Australia, and Western Europe, value personal independence and individual achievement. Identity is defined in terms of self-esteem, personal goals and attributes, and personal rights and liberties. Cultures based on socially connected collectivism, like those of many parts of Asia and Africa, value interdependence, tradition, and harmony, and they define identity in terms of group goals and commitments and belonging to one's group. Within any culture, the degree of individualism or collectivism varies from person to person.

Front 10

What are some ways in which males and females tend to be alike and to differ?

Back 10

Human males and females are more alike than different, thanks to their similar genetic makeup. Regardless of our gender, we see, hear, learn, and remember similarly. Males and females do differ in body fat, muscle, height, age of onset of puberty, and life expectancy; in vulnerability to certain disorders; and in aggression, social power, and social connectedness.

Front 11

How do nature and nurture together form gender?

Back 11

Biological sex is determined by the twenty-third pair of chromosomes, to which the mother contributes an x-chromosome and the father either an x (producing a female) or a y-chromosome (producing a male). A Y chromosome triggers additional testosterone release and male sex organs. Gender refers to the characteristics, whether biologically or socially influenced, by which people define male and female. Sex-related genes and hormones influence gender differences in behavior, possibly by influencing brain development. We also learn gender roles, which vary with culture, across place and time. Social learning theory proposes that we learn gender identity as we learn other things- through reinforcement, punishment, and observation.