Ethology

Definition

Ethology is the study of the biological bases of behavior. This subdiscipline of the behavioral sciences uses methods of objective observation, detailed analysis, and experimentation to define the processes underlying the development, function, causative mechanisms, and evolution of behavior patterns. Originally, ethology focused on behavior patterns thought to require little or no learning for their expression. Gradually, however, as knowledge of the developmental influences underlying the expression of various behavior patterns emerged, a realization that individual experience plays an important role in the expression of species-specific behavioral patterns has come to be accepted.

History and Modern Usage

Charles Darwin promoted the idea that humans and animals shared certain behavioral traits, an idea that was important in establishing the approach to comparative studies of behavior. Oskar Heinroth, studying ducks, and Charles Whitman, studying domestic pigeons, noted the similarities of certain behavior patterns used in courtship and deduced that these patterns were as typical of a species or race as morphological characteristics (i.e., the way they look physically). Thus arose the concept that behavior could be a heritable trait and, as genetic mechanisms became increasingly understood, that natural selection could exert its influence on behavior for survival, as it could on any other adaptation. Ethologists have long been interested in creating models of the nervous system that would explain how species-specific behavior patterns were expressed. Communicative behavior was of particular interest; hence, the mechanisms that imparted to others the ability to correctly interpret and respond to specific patterns of behavior also was of great interest. Several concepts arose out of this line of research and conceptual thinking.

The fixed action pattern was proposed by Konrad Lorenz to characterize a highly stereotyped behavior pattern that was a response to specific stimuli (releasers) from conspecifics. Nikolaas Tinbergen refined the releaser concept to apply to specific components of a communicative behavior (including the body parts involved in its expression), such as the red spot on a gull's bill that activated feeding behavior on the part of a chick. Some communicative gestures were found to consist of complicated interactions between signaler and receiver, such as the “dance” of honey bees studied by Karl von Frisch and others. The explosion of behavioral studies arising out of these conceptual analyses and detailed behavioral studies were recognized by the [Page 316]awarding of the Nobel Prize in physiology and medicine to Lorenz, Tinbergen, and von Frisch in 1973. Over the past 50 years or so, ethology has become difficult to segregate from sister disciplines, including neuroethology (studying the neural bases of speciesspecific behavior), behavioral endocrinology (studying the hormonal basis of species-specific behavior), and behavioral ecology (including the factors that promote group organization in a variety of species, including humans). Integration of the approaches and concepts of ethology with those of psychology has led to the emergence of exciting and very productive disciplines of behavioral biology and behavioral neuroscience, as well as innovative approaches to studying and understanding behavioral pathology.