Book excerpt: Does knowing a person?s gender give us a reliable sense of how aggressive, competitive, or emotional he or she is? In this volume leading scholars examine different aspects of this issue. Carol Tavris discusses the state of gender research and the reasons for the continuing popularity of essentialist theories of gender opposition. Nicki Crick and a team of researchers reassess stereotyped assumptions about gender and aggression, employing a more comprehensive definition of aggression as damaging relations rather than only bodies. Diane Gill looks at the relationship between gender and sports competition, explicating how the unique social context of sports affects gender perceptions and performances. Reed Larson and Joseph Pleck question the popular conception of men as less emotional than women, studying gender differences in ?felt? rather than ?expressed? emotions in daily life. Leonore Tiefer considers the ways in which gender roles in sexuality are socially rather than biologically constructed.