Behavior Genetics and Evolutionary Psychology

Members of the human family share common behavioral tendencies but are also strikingly diverse. To what extent are we shaped by our heredity and to what degree by our life history? The conclusions—that nature is crucially important and that nurture is crucially important—are central to today’s psychology. Genes provide the blueprints that design both our universal human attributes and our individual traits. Behavior geneticists explore individual differences. By using twin, adoption, and temperament studies, they assess the heritability of various traits and disorders. Their research indicates that both nature and nurture influence our life courses. We are products of interactions between our genetic predispositions and our surrounding environments. Molecular geneticists search for genes that put people at risk for genetically influenced disorders, which has potential benefits as well as risks. Evolutionary psychologists focus on what makes us alike as humans. They study how natural selection favored behavioral tendencies that contributed to the survival and spread of our genes. For example, in explaining gender differences in sexual behavior, they argue that women most often send their genes into the future by pairing wisely, men by pairing widely. Critics maintain that evolutionary psychologists make too many hindsight explanations and underestimate the role of culture.