Comparative Psychology

Comparative Psychology

Comparative psychology usually refers to the study of the behavior and mental life of animals other than human beings. However, scientists from different disciplines do not always agree on this definition. Comparative psychology has also been described as a branch of psychology in which emphasis is placed on cross-species comparisons—including human-to-animal comparisons.

However, some researchers feel that direct comparisons should not be the sole focus of comparative psychology and that intense focus on a single organism to understand its behavior is just as desirable, if not more. Donald Dewsbury reviewed the works of several psychologists and their definitions and concluded that the object of comparative psychology is to establish principles of generality focusing on both proximate and ultimate causation.

It has been suggested that the term itself be discarded since it fails to be descriptive of the field but no appropriate replacement has been found. If looking for a precise definition, one may define comparative psychology as psychology concerned with the evolution (phylogenetic history and adaptive significance) and development (ontogenetic history and mechanism) of behavior.

Using a comparative approach to behavior allows one to evaluate the target behavior from four different, complementary perspectives, developed by Niko Tinbergen. First, one may ask how pervasive the behavior is across species. Meaning, how common is the behavior in animals? Second, one may ask how the behavior contributes to the lifetime reproductive success of the individuals demonstrating it. Meaning, does it result in those animals producing more offspring than animals not showing the behavior? These two questions provide a theory for the ultimate cause of behavior.

Third, what mechanisms are involved in the behavior? Meaning, what physiological, behavioral, and environmental components are necessary and sufficient for the generation of the behavior? Fourth, a researcher may ask about the development of the behavior within an individual. Meaning, what maturational, learning, social experiences must an individual undergo in order to demonstrate a behavior? These latter two questions provide a theory for the proximate causes of behavior. For more details see Tinbergen's four questions.