According to the received view of the history of ethology and comparative psychology, ethology developed as the study of insects, fish, and birds in the field and comparative psychology as the study of rats learning mazes in the laboratory; there was little contact between them throughout the century. This view does not withstand close analysis. Throughout the century, comparative psychology, as differentiated from other approaches within animal psychology, has been closer to the ethological approach than generally has been acknowledged. 1 There have been repeated contacts and mutual influences. Although different in some respects, comparative psychology and ethology share many characteristics and much of their histories.