Political Science, Department of


Date of this Version

October 2006


Published in Organizational Behavior and Human Decision Processes 101 (2006) 20–35. Copyright 2006 Elsevier Inc.


Evolutionary biological theories of group cooperation predict that (1) group members will tend to judge cooperative co-members favorably, and freeriding co-members negatively and (2) members who themselves cooperate more frequently will be especially likely to make these social judgments. An experiment tested these predictions among Shuar hunter-horticulturalists. Subjects viewed depictions of pairs of workers who varied in the extent to which they had contributed to, and benefited from, a team project. Subjects were then asked to judge which worker deserved more respect, and which deserved more punishment. When judging between unequalcontributors, all subjects tended to favor more cooperative (i.e., higher-contributing) workers. However, when judging between equal-contributors/unequal-benefiters, male subjects who themselves often engaged in team cooperation tended to favor more cooperative (i.e., lower-benefiting) workers, while subjects who were female and who therefore rarely engaged in team cooperation tended to favor less cooperative (i.e., higher-benefiting) workers.