We show that subjects who set their minimum acceptable offer to zero in an ultimatum game are the most generous players in a dictator game. This finding challenges the interpretation of the acceptance of low offers as payoff-maximizing behavior.

We investigate parochial altruism, the combination of in-group altruism and out-group hostility, in an experimental conflict game preceded by a prisoner’s dilemma. Our data are consistent with parochial altruism, but cannot be explained by in-group pro-sociality or out-group hostility alone.

We study whether math ability affects decision making under risk. Participants where divided in three math skill groups according to their performance in a GRE-like math test. We find no difference in behavior between groups across several risk measuring tasks.