Ethology, the Comparative Study of Animal Behavior

Abstract

Ethology has contributed a considerable number of verifiable facts to human knowledge which do not seem to fit wholly within existing physiological or psychological explanations of animal behavior. From these facts are described: (1) Certain patterns of behavior, termed instinctive movements, possess taxonomic value among diverse groups of animals, i.e., they often show much the same species-specificity as morphological structures; (2) these fixed patterns of behavior (presumed to have evolved from homologous, ancestral behavior) may be studied and partially understood from the viewpoint of phyletic descent; and (3) there seems to exist an unexplained lawfulness governing behavior which is expressed through instinctive movements, leading to associated phenomena described theoretically as displacement activities, intention movements, ambivalent responses, regressive behavior, and inherited sequences of movements. Ethological investigation has not only focused attention on hypotheses about the physiological mechanisms underlying behavior, but also has advanced assumptions about how various physiological mechanisms, fixed patterns of behavior, and specialized structures have become integrated into a unified system in the course of their evolution.