The general psychoevolutionary theory of emotion that is presented here has a number of important characteristics. First, it provides a broad evolutionary foundation for conceptualizing the domain of emotion as seen in animals and humans. Second, it provides a structural model which describes the interrelations among emotions. Third, it has demonstrated both theoretical and empirical relations among a number of derivative domains including personality traits, diagnoses, and ego defenses. Fourth, it has provided a theoretical rationale for the construction of tests and scales for the measurement of key dimensions within these various domains. Fifth, it has stimulated a good deal of empirical research using these tools and concepts. Finally, the theory provides useful insights into the relationships among emotions, adaptations, and evolution.