Why animals love to play

Ask, Nov/Dec 2003 by Braaf, Ellen R

How could playing grow the brain? As Byers explains it, there's an overproduction of connections between nerve cells in the brain after birth. If these "extra" connections are not used, they disappear. Playing animals use many connections and so establish new pathways in the brain. The brain, in a way, is remodeled as the animal grows.

In the end, Byers discovered that when it comes to marsupial brain size, "if you snooze, you lose." Koalas sleep up to 20 hours a day. They played the least and had the smallest brains (compared to their body size). The frolicking wombats played the most and had the biggest brains.

Do Animals Play Fair?

All play is based on trust and requires cooperation. Marc Bekoff says, "Cheaters are not tolerated in play. If an animal cheats a lot, he'll have trouble getting other animals to play with him." Animal play has rules. When one animal invites another to play-and the other agrees-they're making a pact that says: "If you'll play with me, I'll play with you. I won't hurt you. I won't bite you around your eyes. I won't body-slam you too hard. I won't try to dominate you." Play signals are clear. If an animal breaks that pact, he'll have trouble finding playmates. Because play is so important, an animal that doesn't get to play may not survive.

Most behavior experts believe that only humans have a sense of right and wrong. But Bekoff disagrees. He believes that animals practice "wild justice," and that playing by the rules makes them more fit in the struggle for survival. "I'm starting to find evidence that a well-developed sense of fair play helps nonhuman animals live longer, more successful lives," Bekoff says. "Virtue is its own reward-fairer is fitter."