This trusted text examines the biological, psychological, and social science of human sexuality, provides practical information needed for everyday living, and familiarizes students with research methods used in sexuality. The author team features a unique combination of a psychologist and a sociologist, which gives this text a distinct interdisciplinary perspective. The thoroughly revised ninth edition features cutting-edge research, a new photo program, and a new companion <i>SexSource</i> CD-ROM packaged free with every new copy of the text.