The Trust Game

The Trust Game

While cleaning one morning, I noticed Thiele and Herbie sitting very closely together and laughing. I paused what I was doing to observe them and saw that Thiele had her hand in Herbie’s mouth and both were laughing hysterically as if it were the funniest game in the world. After about a minute of having her hand in his mouth Thiele stuck half her face in his wide open mouth and Herbie was careful not to hurt her with his large canine teeth. Both chimps continued giggling in this awkward position for a few more minutes, until Herbie decided it was time to place his forearm sideways in Thiele’s mouth. Herbie and Thiele stared into each other’s eyes as they laughed and as I watched I felt as if I were missing out on an inside joke.

Though I would never have imagined that this sort of playing would result in such side-splitting laughter, this game promotes great trust between chimps. Play in general is a great way to strengthen bonds between chimps, just as it is in humans. A chimpanzee’s canine teeth can break bones, so by willingly placing body parts inside Herbie’s mouth, Thiele was showing a lot of trust in Herbie to be gentle and to know that this was only a game.

Herbie and Emma embrace.

Herbie and Emma embrace.

Renowned primate behavior professor, Frans de Waal, notes witnessing the same phenomenon with young chimpanzees and writes: “A code of conduct is dictated by the need to get along. Mutual trust is implied during play when young chimps become fully entangled, gnawing on each other’s hands and feet. If the game gets too rough, amends will need to be made in order for the fun to continue.”

Other animals have been known to build trust through play as well. American Zoologist, Mark Bekoff, studies the behavior of canids (wolves, dogs, coyotes, etc.) and he concluded through his research that “canid play is subject to rules, builds trust, requires the consideration of others, and teaches the young how to behave.” If one partner gets too rough and hurts another, the game stops right away.

Capuchin monkeys have been observed bonding through similar games, such as sticking their fingers in another’s mouth, eye, or nose and sitting together in this way for long periods of time.

Building trust is incredibly important in all social animal species, and games are a great way to do this, especially to teach youngsters social rules. The chimps at Chimps Inc did not have typical chimpanzee childhoods and when they joined the group at this sanctuary, they had to start at the beginning, to learn the rules of the group and to build these strong bonds with their new family. Even the adults still love to play and it is an incredible honor to be able to witness these relationships strengthening.

 Kaleigh, volunteer





de Waal, Frans (2013-03-25). The Bonobo and the Atheist: In Search of Humanism Among the Primates. W. W. Norton & Company. Kindle Edition.