Figure 3

Cooperation during Phase II. Participants’ average APD cooperation frequency as a function of the round number and over the entire phase (inset box) for all experimental treatments. Participants cooperate to the same extent in CH and RH treatments and at all time less frequently in SH treatments (comparison of pairwise interaction average cooperation level distributions: SH-CH MW U = 34448, ^***p < 0.001; SH-RH MW U = 16636, ^***p < 0.001; CH-RH MW U = 20988, p = 0.618). Error bars represent standard error of the mean over all treatments.