It’s not unusual for chimpanzees to fight. Chimpanzee society is naturally aggressive and even violent. However, visitors at ...

Synchronized urination may reinforce social bonds and improve group cohesion among chimps, according to new research.

Social closeness, measured by time in close proximity and grooming with another chimpanzee, had no effect on the peeing phenomenon — unlike with social yawning, which increases in socially ...

as in the case of grooming and yawning. Instead, the researchers found that rank played a role. Low-ranking individuals were more likely than others to start peeing if a chimp nearby did.

long scratch that invites grooming; and a two-footed stomp that means “Stop that!” No other chimpanzees are known to use the hand-eye gesture like Lindsay and Beryl do. It’s their own ...