One member of each pair of 52 undergraduates, referred to as a learner, was trained BC conditional discriminations, with B stimuli as the samples and C stimuli as the correct comparisons. Responses of the learner were either reinforced or punished by another member of each pair, an instructor, who had previously mastered AC conditional…

Our ability to learn about the reputations of others--that is, who is likely to cooperate versus cheat--contributes greatly to cooperativeness in society. There has been recent debate whether humans employ memory bias favoring cheaters (i.e., there is an evolved module for the detection of cheaters) or whether no such bias exists (i.e., reputation…