Disproportionate attention has long been paid to males in human and other social systems. The basic structures used to explain social behavior in sociological and biological work have overwhelmingly emphasized the significance and shape of male behavior and far less female behavior which is surely at least as important. Stratification, sexual selection, and natural selection of what women do among themselves and how they relate to men was explored in this volume for the first time. It is now available in a paperback edition, with a new introduction by Lionel Tiger. Do females conduct aggressive encounters with each other? Or do they have no impact on mate selection and hence on the future of the genotype? Is the main negotiation of females with males and not among themselves during this selective process? Do the usually larger size and frequently more elaborate behavioral displays of males betray the fact that the burden of selective functioning falls on males and not on females? It is improbable that the answer to these questions is "yes" and that there is little or nothing happening in all-female groups that affects not only how their communities operate but, more importantly in the long run, the genotype of their species. For those species in which gregarious social behavior is a sine qua non for successful reproduction, what are the principles of selection that operate through females? Are female hierarchies more abrasive or generous than male ones? Do they focus more on reproduction than production? What are the forms of female social grouping that either support, modify, inhibit, or stimulate sexual and hence natural selection? This work goes far beyond the slogans of our time for important responses to basic questions.