Kin recognition, or the ability to recognize one's genetic relations, is universal throughout the animal kingdom, from amebas to humans. This trait benefits the organism by helping to insure the survival of a specific gene group, and it is also an important factor in mate choice. Indeed, kin recognition is one of the fastest growing and most exciting areas of behavior. The study of kin recognition requires a multidisciplinary approach, and Dr. Hepper has brought together leading researchers from zoology, biology, psychology, and sociology to create a thought-provoking and critical analysis of our current knowledge of the phenomenon, with particular emphasis on the underlying processes involved and their significance for the evolution of social behavior. Together they attempt to answer the questions of how individuals recognize other individuals as kin, nonkin, or different classes of kin and why they respond differently to kin and nonkin.