Fig. 5.

Cooperation and attack frequencies by rank position and treatment. Highly ranked participants cooperate and engage into conflicts more often than lowly ranked ones for both hierarchical treatments. Both frequencies follow linear fits. For comparison purposes with large hierarchy treatment results, we report dashed lines for the small hierarchy treatment as projected frequencies for ranks that are not reachable in small groups. Cooperation and attack frequencies of the egalitarian group treatment are reported as the average value observed in the entire treatment. Error bars represent the SEM considering each individual decision as an independent observation.