Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Effect of (a) food sharing compared with grooming and (b) five behavioural and social contexts on the urinary oxytocin concentration in wild chimpanzees. Residuals are shown ± standard error following model 3. Number of samples included in each context are shown beneath each plot (total n = 182 samples, 34 subjects; *p < 0.05, **p < 0.01, ***p < 0.001).
