Fig. 1.

Experimental setup. In each treatment, participants went through 60 rounds including two phases. In the first phase, they take part in a PGG with a multiplication factor set to be half of the group size. In the second phase, they could engage into conflict against their coupled participant to steal from them their round earnings. In the egalitarian group treatment, ranks were not present and conflicts were randomly decided with 50% probability of winning for both participants. In the Hierarchical (small hierarchy and large hierarchy) treatments, ranks changed after each engaged conflict and winning probabilities were rank-dependent. See the main text and the Supplementary Information (SI) Appendix for more details on the experiment.