Gender is a subject of much interest to social scientists who study groups, and there are a number of reasons for this. First, much of our daily life is spent in mixed-gender groups. For example, a family—a group in which much of our social behavior occurs—usually contains members of both genders. Thus, most of us are required to interact with members of the other sex on a regular basis. Second, gender seems to hold an important place in our conception of ourselves and other people. One of the first questions we ask about a new baby is, “Is it a boy or a girl?” We are uncomfortable when someone's gender is ambiguous. And third, gender affects behavior both within and between groups in a variety ...