Fig. 1.

(A and B) Evolutionarily stable probabilities of escalated fighting and (C and D) mean payoffs per individual across all encounters, as a function of the total cost c of losing a fight (expressed relative to the value of victory v, and plotted on a log scale), in the original pairwise-interaction hawk−dove game (blue curves), and in the group-interaction game (red curves). A and C show results when leaders claim a disproportionately large share of the benefits of victory, that is, when d_v > 0 (solid red curves, d_v = 0.25; dotted red curves, d_v = 0.5; dashed red curves d_v = 0.75; d_c = 0 in each case); B and D show results when leaders suffer a disproportionately small share of the cost of losing a fight, that is, when d_c > 0 (solid red curves, d_c = 0.25; dotted red curves, d_c = 0.5; dashed red curves d_c = 0.75; d_v = 0 in each case). In all cases, n = 5. (E and F) Mean payoffs to followers per encounter when leaders control group behavior (solid curves), compared to the potential maximum payoffs obtainable if a follower were to seize control of the group and impose its own preferred behavior (dashed curves), as a function of the total cost c of losing a fight (expressed relative to the value of victory v, and plotted on a log scale). Exploitative leadership occurs where the solid and dashed curves diverge. Parameter values E, (d_v = 0.5, d_c = 0, n = 5); F, (d_v = 0, d_c = 0.5, n = 5).