High-arm grooming is a form of chimpanzee grooming in which two individuals mutually groom while each raising one arm. Palm-to-palm clasping (PPC) is a distinct style of high-arm grooming in which the grooming partners clasp each other's raised …
Knowledge of chimpanzee development has played an essential role in our understanding of the evolution of human ontogeny. However, recent studies of wild ape dentitions have cast doubt on the use of developmental standards derived from captive …