CHAPTER 3: NATURE, NURTURE, AND HUMAN DIVERSITY Behavior Genetics: Predicting Individual Differences Behavior geneticists explore our individual differences differences and how they are affected by heredity and environment. Using methods such as twin, adoption, and temperament studies, they identify the heritability of various traits and disorders. Studies Studies of the inheritance inheritance of temperam temperament, ent, and of twins and adopted adopted children children,, provid provide e scien scientif tific ic suppo support rt for the idea idea that that nature nature and nurtur nurture e influe influence nce one’s one’s developin developing g personal personality. ity. Genes and environme environment—b nt—biolo iologica gicall and social social factors— factors— direct our life courses as their effects intertwine. Molecular Molecular geneticists geneticists are on a fast-movi fast-moving ng frontier in their their work work to identify the specific genes that influence behaviors.
Evolutionary Psychology: Understanding Human Nature Genes (DNA segments that form the chromosomes) are the biochemical units of heredity. They provide the blueprint for protein molecules, the building blocks of our physical and behavioral development. Evolution Evolutionary ary psycholo psychologist gists s study study how natural natural selectio selection n has shaped shaped our universa universall behavior tendencies. They reason that if organisms vary, if only some mature to produce surviving offspring, and if certain inherited behavior tendencies assist that survival, then nature must select those tendencies. They believe this helps explain gender gender differenc differences es in sexuality. sexuality. Critics Critics maintain maintain that evolution evolutionary ary psycholo psychologists gists make too many hindsight explanations. explanations.
Parents and Peers Gene Geneti tic c infl influe uenc nces es are are perv pervas asiv ive, e, but but so are are pren prenat atal al envi enviro ronm nmen ents ts,, earl early y experiences and peer influences. Sculpted by experience, neural interconnections multiply rapidly rapidly after birth. Both parents and and peers influence influence development. Parents Parents model education, discipline, and responsibility to name a few while peers influence learning to cooperate with others, and finding appropriate ways to interact with people of a similar age.
Cultural Influences Culture Culture consists consists of behavior behaviors, s, ideas, ideas, attitudes, attitudes, values, and tradition traditions, s, which which are shared by a group and passed from generation to generation. Most animals exhibit culture at a rudimentary level but humans are able to develop more quickly due to our ability to communicate verbally, our preservation of innovation, and our division of labor. Human variations across cultures and over time show how differing norms, or expectations, guide behavior. Cultures differ in their norms for personal space, expressiveness, and pace of life. Cultures change over time as well. However, this rapid rapid chang change e is not attribu attributed ted to chang changes es in the gene pool, pool, which which occur occur more slowly, but to culture itself.
A culture can vary depending on how its people view themselves—as individuals and as part of a group. There are cultures that value individualism over collectivism and vice versa. Whether the culture focuses more on the “I” or the “We” often determines the values of the culture. These variations in cultural values influence child-rearing practices in particular. One cultural group may feel that their method of rearing children is better than another’s when, in fact, every culture can raise children successfully. Despite cultural differences, we are all humans and undergo the same cycle of life.
Gender Development Males and females are similar in many ways. People of each gender may, for example, share the same level of intelligence. However, there are distinct gender differences with regard to social behavior. Research studies show gender differences in aggression, social power, and social connectedness. These similarities and differences are created by both nature and nurture. Although males and females share similarly adaptive bodily procedures, differing sex chromosomes and differing concentrations of sex hormones lead to significant physiological sex differences. Yet gender differences vary widely depending upon cultural socialization through social learning and gender schemas. Myers, Myers Psychology Eighth Edition © 2006 Worth Publishers
