This textbook presents a unified theoretical perspective of comparative psychology, presenting the traditional principles of the field combined with the strength of current empirical research.

Drawing on a rich historical tradition, Principles of Comparative Psychology looks to the future of the discipline in the 21st century. The authors have conceived this field broadly, as the study of origins of all behavior, while utilizing a developmental perspective in which behavior is understood to be the result of a fusion of biological and psychosocial factors. Particular recognition is given to some of the unique problems of the discipline in carrying out a careful application of the scientific method to its chosen subject matter of mind and behavior.