Winning and losing: an evolutionary approach to mood disorders and their therapy.

OBJECTIVE: To advance a new evolutionary model that examines the effects of winning and losing on mood and physiological variables. Previous studies have focused on the involuntary defeat strategy in de-escalating conflict. Here, we propose that there also exists an involuntary winning strategy (IWS) that is triggered by success and characterized by euphoria and increased self-confidence. It motivates efforts to challenge, and promotes reconciliation.
METHOD: Previous studies are presented, including data on student athletes, demonstrating the impact of winning and losing on mood.
RESULTS: Winning is consistently shown to be related to physiological changes such as increased testosterone and serotonin levels in primates. It reliably leads to mood changes that serve to motivate winners to continue their competitive efforts.
CONCLUSION: When the IWS functions optimally, success leads to success in an adaptive cycle. Over time, the initial differences between the winners and losers of agonistic encounters become magnified in a process known as difference amplification. As a result of assortative mating, the children of people who have entered into an adaptive cycle will inherit traits from both parents that will, in turn, give them an increased competitive advantage. In this manner, difference amplification could have accelerated human evolution by natural selection. Vignettes of clinical interventions are also used to illustrate therapeutic strategies designed to disrupt maladaptive cycles and promote adaptive behaviour.