The Social Competition Theory of Depression: Gaining From an Evolutionary Approach to Losing

Evolutionary approaches have potentially much to offer to our understanding of personality, social behavior, and psychopathology. In a recent article (Zuroff, Fournier, & Moskowitz, 2007), we sought to test the social competition theory of depression, which provides an account of the social behavior of depressed individuals through postulation of an Involuntary Defeat Strategy (IDS). The IDS is elicited by the perception of a defeat from which the person cannot escape and is postulated to have served the adaptive function of restraining combatants from entering or continuing in hazardous contests with superior rivals. Relatively brief activation of the IDS would correspond to mild depression or dysphoria. Prolonged activation of the IDS would present itself as debilitating clinical depression. Utilizing an event–contingent recording method to capture the day–to–day social interactions of individuals, we examined whether mildly depressed individuals dynamically adjust their behavior in response to the behavior of their interaction partners in ways consistent with the social competition theory. Considerable support for the social competition theory was found. In their commentary on this article, Pettit and Yaroslavsky (2007) suggest four main criticisms of the social competition theory of depression: (1) several of our key findings could be understood equally well from