Two studies were conducted to replicate and extend previous findings on the effect of uncooperative behavior on group cooperation (the "bad apple" effect). Study 1 (56 women, 40 men; M age = 23.5 yr.) manipulated information about contributions from the bad apple, controlling for overall contributions to a group account. Study 2 (50 women, 34 men; M age = 20.4 yr.) compared the effects of a bad apple and a good apple on cooperation. The social value orientation of participants was measured to explore individual differences in the bad apple effect. The results revealed a bad apple (a) decreased cooperation among individuals with proself and prosocial orientations in Study 1, and (b) had a greater effect than a good apple on those who were proself compared to prosocial in Study 2.