Leadership index (LI) differences at the end of training (average within the last training epoch).

(a) ΔLI at VP₁ is calculated as the difference between LI₂₁ and LI₁₁. (b) ΔLI at VP₂ is calculated as the difference between LI₁₂ and LI₂₂. Error bars denote the standard error (SE). (c) ΔLI at VP₁ and VP₂, for each dyad in all three groups, compared with model predictions. The large dots denote the No partner (green) and the Nash (violet) model predictions. The plots indicate the population means. Asterisks indicate statistically significant differences (*P < 0.05, **P < 0.01, ***P < 0.001).