We compare behavior in modified dictator games with and without role uncertainty. Subjects choose between a selfish action, a costly surplus creating action (altruistic behavior) and a costly surplus destroying action (spiteful behavior). While costly surplus creating actions are most frequent...

We present evidence from an experiment in which groups select a leader to compete against the leaders of other groups in a real-effort task that they have all performed in the past. We find that women are selected much less often as leaders than is suggested by their individual past performance....