The term psychobiology is often used to refer to various biological approaches to psychology that have emerged in the 20th century. The term generally has been used to locate an approach with respect to both disciplines, sometimes in an effort to distance the author from psychology as a whole. When viewed in broad historical perspective, however, it is seen that more often the word has been used to designate a number of very different forms of opposition to the excessive reductionism characteristic of many biological approaches to psychology. "Psychobiology' represents a family of attempts to incorporate biological perspectives in the study of dynamic processes in whole, integrated, adapted, and organized organisms, not to reduce complex, dynamic relationships to physiological processes.