Abstract

Forber and Smead (2014) analyze how increasing the fitness benefits associated with prosocial behavior can increase the fitness of spiteful individuals relative to their prosocial counterparts, so that selection favors spite over prosociality. This poses a problem for the evolution of prosocial behavior: As the benefits of prosocial behavior increase, it becomes more likely that spite, not prosocial behavior, will evolve in any given population. In this article, I develop two game-theoretic models that, taken together, illustrate how synergistic costs and benefits may provide partial solutions to Forber and Smead’s paradox.