ABSTRACT
Some titles of books have become classics in their own right. The expression of emotions in animals and man of 1872 is one of them. In this ground-breaking work the great evolutionary biologist Charles Darwin categorized emotional expression from a comparative and evolutionary perspective. Since then emotions have figured prominently in human psychology as a subject of interest. By contrast the term has hardly occurred in ethological texts (cf. McNaughton, 1989). Students of animal behavior have rarely referred to emotions, obviously because these have traditionally been described in terms of subjective experiences. Ethologists have tended to avoid the use of such intervening variables in attempting to relate behavioral sequential contingencies directly to contextual contingencies. Accordingly characterizations of expressive states have preferably been put in terms of behavioral tendencies and their motivating factors. This is not to imply that there are no behavioral manifestations in nonhuman species that are not analogous or even homologous to emotional expression. It is the great merit of Frijda (1986) that he has presented a perspective on emotions and emotional behavior that integrates the different views and approaches, psychological, comparative and evolutionary, and physiological that have been developed concerning emotional behavior and its underlying mechanisms.
