Pasa and Yoyo, two female chimpanzees, are best friends. They spend their afternoons lounging together in the warm grass of ...

Human relationships (or should I say, chimpanzee relationships?) are truly profound, aren't they? Even if you are usually very close, don't the lines of what is "forgivable" or "unforgivable" change ...

A single pull of the rope was all it took to steal a friend’s pineapple. However, the female chimpanzee “Yoyo” turned her ...

Wrangham previously established the "imbalance of power" hypothesis, which explains the distribution of coalitional violence among chimpanzees, and with Glowacki, Wrangham here examines the pattern of ...