Effect of inequality on cooperation: Heterogeneity and hegemony in public goods dilemma

•Two properties of heterogeneity: level of inequality, asymmetry of distribution.•Symmetrically heterogeneous groups cooperated less than homogeneous groups.•Larger inequality led to less group cooperation only in symmetric distribution.•High endowed members have higher self-efficacy in hegemonic than symmetric groups.•High endowed members have larger fear of being a sucker in hegemonic groups.

We conducted two studies to explain inconsistent findings on the effect of resource inequality based on two properties of heterogeneity: (a) level of inequality and (b) asymmetry of resource distribution. We confirmed that symmetrically heterogeneous groups cooperated less than homogeneous groups did. We also found that larger resource inequality led to less cooperation. More importantly, the effect of inequality was different among groups with different distributions of resources – cooperation declined in groups with a symmetrical distribution of resources but did not decline in groups with a hegemonic distribution. Hegemonic distribution also affected psychological states as resource inequality changed. High endowment members reported higher self-efficacy when distribution was hegemonic than symmetric. However, they also reported more fear of being a sucker in hegemonic groups.