Fig. 3.

Aggression in predator and prey as a function of treatment. (A) Force of aggression in predators and prey under oxytocin vs placebo (range: 1–10, displayed ± SE); (B) Compared with placebo, oxytocin reduces aggression frequency of predator but not of prey (range: 0–5, displayed ± SE); (C) Compared with placebo, oxytocin reduces time in milliseconds taken to decide in predators but not in prey (range: 0–6000; displayed ± SE). Contrasts marked with * are significant at P < 0.05 (directional t-tests, with N = 27).