While gender norms in contemporary America have changed in recent years, boys and girls still tend to develop gendered identities and play with fellow boys and girls. Again, children emulate peers’ gender expressions more so than those of their parents: “During the formative years of childhood, a girl becomes more similar to other girls and a boy becomes more similar to other boys. Rowdy girls become less rowdy; timid boys get bolder” (206). Harris argues boys and girls are born with innate differences, and this is why various cultures develop similar norms in recognition of these differences. Anthropologist Margaret Mead (first mentioned in Chapter 9) popularized the idea that babies could be socialized into gendered behavior. However, Harris believes most cultures share gender stereotypes of men as hunters and warriors and women as gatherers and nurturers. These stereotypes are not necessarily negative, but generalizations. Because of humans’ tendency to categorize, people regard groups of either men or women as more alike than they are.

From ages six to 12, children tend to form friendships with fellow boys and girls. In order to socialize, children self-categorize—sometimes with gender expression that does not align with their sex assignment at birth.