What Is Mood for ?

What evolutionary advantages have shaped the human capacity for mood? Answers are suggested if moods are seen as specialized states that increase our ability to cope with certain situations. This target article considers the hypothesis that high mood helps individuals take full advantage of the opportunities in propitious situations, whereas low mood motivates them to seek help, be socially submissive, conserve resources, and consider alternative strategies in situations where investments are not paying off. RATIONALE FOR SOLICITING PEER COMMENTARY: The "skywriting" format requires paring away all but the skeleton of the argument and unfortunately allows few citations. Nonetheless, the format is excellent for my goal of encouraging psychiatrists, psychologists, and evolutionists to recognize that the question, "What is mood for?" is legitimate, important, and answerable. I would especially appreciate comments about (1) the basic approach of seeking evolutionary explanations for emotions in the adaptive challenges of the situations that shaped them, (2) alternative hypotheses about the functions of mood, (3) the plausibility of the "propitiousness hypothesis" and (4) additional ways in which it can be tested.