Developmentalists have placed too little emphasis on how biology interacts with environmental influences to guide children's gender development, said Stanford University psychologist Eleanor Maccoby, PhD, at APA's 2000 Annual Convention in Washington, D.C.

Research on gender development has mapped out how the sexes differ in their preferences, interests and activities and has tried to uncover the reasons why such differences emerge and why some children are more sex-typed than others, Maccoby said. But "this strategy of seeking to explain gender divergence during childhood through analyzing individual differences insex-typing has not served us very well," she said, speaking in acceptance ofthe Eleanor Maccoby Book Award in Developmental Psychology for her 1998 book, "The Two Sexes: Growing Up Apart, Coming Together."

Although children's environment indeed plays an important role in their gender development, as is evidenced by studies of cultural differences in gender roles, Maccoby argued that direct socialization into gender roles by parents doesn't appear to be as singular an influence on children's sex-typed preferences and behaviors as once was thought.

"By and large, the daily routines of family life do not have much impact on the strong tendency of children to separate into same-sex groups, and probably not on the distinctive activities enacted by male and female groups," Maccoby said.

Nonetheless, she pointed out, families likely do influence other aspects of children's development, such as the roles children play within the gender-segregated peer culture. And, she said, research has indicated that environmental conditions not only influence behavior directly, but also exert an indirect effect by altering biological processes.

Maccoby described research that underscores biology's role in shaping behavior. Experiments with nonhuman primates show that administering testosterone to female fetuses late in gestation yields more typically masculine behavior, she observed. What's more, she said, ethological studies reveal that gender divergences are not limited to humans, but also appear in other animals.

Said Maccoby: "The parallels are sufficiently strong, I believe, to give us some confidence that there is an evolved, genetic basis for several of the robust gender divergences that have been documented in human children."