Relative facial width, and its association with canine size and body mass among chimpanzees and bonobos: Implications for understanding facial width‐to‐height ratio expression among human populations

Our findings indicate that CCH and facial breadth may serve subtly different signaling functions among Pan taxa. Further research into the circumstances in which wide faces evolved among chimpanzees and bonobos will likely afford deeper insights into the function of relatively wide faces in the context of visual signaling among humans and our extinct hominin relatives.