Investigation into the hormonal control of sexual behavior has a rich and extensive history. For many researchers currently active in the field, the physiological psychologist Frank A. Beach is recognized as the modern father of the study of hormones and behavior. His publication of the seminal book Hormones and Behavior-A Survey of interrelationships Between Endocrine Secretions and Patterns of Overt Response, published in 1948, was a compilation of the previous 20 years of research establishing that gonadal secretions acted in the brain and modulated behavior. The question of precisely how hormones can alter brain functioning in a coordinated fashion and profoundly influence the patterns of behavioral responsiveness remains unanswered. As with many research areas, application of new techniques and approaches to the problem reveals additional layers of complexity and previously unimagined relationships between hormones, brain, and behavior. In addition, with the increasing understanding that the brain is a target organ for steroids, the implications of the ramifications of this steroid sensitivity have broadened. The hormonal regulation of sexual behavior is not an isolated aspect of steroid action in the brain; rather, it is one component of a host of physiological responses influenced by steroids. These include such diverse responses as anxiety, aggression, feeding, and learning and memory. An appreciation of the diverse effects of steroids has emerged from studies on sexual behavior, and a mutually beneficial relationship between this and other aspects of behavioral neuroscience has flourished and endured. As with all of neuroscience, this research area has been dynamic and progressive and has additionally benefited from a long history of comparative and integrative approaches to animal behavior. (C) 1996, Elsevier Science Inc.