We analyze equilibria of two-player contests where players have intention-based preferences. We find that players invest more effort compared to the case with selfish preferences and are even willing to exert effort when the monetary value of the prize converges to zero. As a consequence,...

Altruists and envious people who meet in contests are symbionts. They do better than a population of narrowly rational individuals. If there are only altruists and envious individuals, a particular mixture of altruists and envious individuals is evolutionarily stable.