Although not known for their generosity, chimpanzees do regularly share food. Most chimpanzee food sharing does not involve actively handing food to someone else, but rather passively allowing another individual to take it. Aware of this possibility, chimpanzees often beg for food from those who have it – holding out a hand or even reaching toward another’s mouth as he chews. Foods that are shared are those that are high-value, monopolizable, and rare, such as meat, honey, or large fruits. Food sharing appears to strengthen social bonds in chimpanzees. Males typically share meat with their “friends” – other males with whom they frequently groom and who support them in fights. Recent studies by Roman Wittig, Catherine Crockford and colleagues have shown that these social bonds are also mediated by hormones. Both those who share and those who receive food experience increased levels of oxytocin, a hormone involved in social bonds and cooperation.
Dr. Sylvia Amsler is a lecturer in anthropology at the University of Arkansas at Little Rock.
References:
Crockford C, Wittig RM, Langergraber K, Ziegler TE, Zubebuhler K, Deschner T. 2013. Urinary oxytocin and social bonding in related and unrelated wild chimpanzees. Proc R Soc B 280:20122765.
Wittig RM, Crockford C, Deschner T, Langergraber KE, Ziegler TE, Zuberbuhler K. 2014. Food sharing is linked to urinary oxytocin levels and bonding in related and unrelated wild chimpanzees. Proc R Soc B 281:20133096.