Table S2.

Intergroup conflict type model: Effect of the type of intergroup conflict, namely border patrol or intergroup encounter, on urinary oxytocin levels, log-transformed

Term	Estimate	SE	χ2*	P
Intercept	4.399	0.214	–	–
Test predictor
Border patrol†	1.321	0.221	22.227	<0.001
Intergroup encounter†	1.261	0.189	37.522	<0.001
Control predictors
Group‡	−0.358	0.134	7.014	0.008
Sex§	−0.359	0.209	2.788	0.095
Proximity¶	−0.058	0.068	0.714	0.398
Subgroup size#	0.077	0.054	2.010	0.156
Rank||	0.086	0.099	0.614	0.433

Statistically significant results (P ≤ 0.05) appear in bold.

^*Degrees of freedom are 1.

^†,‡,§χ² and P values refer to comparison with the reference categories ^†control, ^‡East group, and ^§female.

^¶,#,||z-transformed, mean ± SD of the original variables: ^¶65.86 ± 29.35 (range 5 to 99), ^#11.45 ± 5.96, and ^||0.61 ± 0.24 (range 0 to 1, with 1 being the highest social rank).