Play (activity) - Play and Animals

Play and Animals

Although ethologists are now studying animal play, historically it has been given comparatively little attention by scientists. This may be due to the nature of such play, which does not have the central theoretical framework on which much scientific theory and study depend.

Evolutionary psychologists believe that there must be an important benefit of play, since there are so many reasons to avoid it. Animals are often injured during play, become distracted from predators, and expend valuable energy. In rare cases, play has even been observed between different species that are natural enemies such as a polar bear and a dog. Yet play seems to be a normal activity with animals who occupy the higher strata of their own hierarchy of needs. Animals on the lower strata, e.g. stressed and starving animals, generally do not play.

One theory – "play as preparation" – was inspired by the observation that play often mimics adult themes of survival. Predators such as lions and bears play by chasing, pouncing, pawing, wrestling, and biting, as they learn to stalk and kill prey. Prey animals such as deer and zebras play by running and leaping as they acquire speed and agility. Hoofed mammals also practice kicking their hind legs to learn to ward off attacks. While mimicking adult behavior, attacking actions such as kicking and biting are not completely fulfilled, so playmates do not generally injure each other. In social animals, playing might also help to establish dominance rankings among the young to avoid conflicts as adults.

John Byers, a zoologist at the University of Idaho, discovered that the amount of time spent at play for many mammals (e.g. rats and cats) peaks around puberty, and then drops off. This corresponds to the development of the cerebellum, suggesting that play is not so much about practicing exact behaviors, as much as building general connections in the brain. Sergio Pellis and colleagues at the University of Lethbridge in Alberta, Canada, discovered that play may shape the brain in other ways, too. Young mammals have an overabundance of brain cells in their cerebrum (the outer areas of the brain – part of what distinguishes mammals). There is evidence that play helps the brain clean up this excess of cells, resulting in a more efficient cerebrum at maturity.

Marc Bekoff (a University of Colorado evolutionary biologist) proposes a "flexibility" hypothesis that attempts to incorporate these newer neurological findings. It argues that play helps animals learn to switch and improvise all behaviors more effectively, to be prepared for the unexpected. There may, however, be other ways to acquire even these benefits of play: the concept of equifinality. The idea is that the social benefits of play for many animals, for example, could instead be garnered by grooming. Patrick Bateson maintains that equifinality is exactly what play teaches. In accordance with the flexibility hypothesis, play may teach animals to avoid "false endpoints". In other words, they will harness the childlike tendency to keep playing with something that works "well enough", eventually allowing them to come up with something that might work better, if only in some situations. This also allows mammals to build up various skills that could come in handy in entirely novel situations.