Physical Activity Play
Anyone who has spent time on a playground, at the local swimming pool, or on a children's athletic field has witnessed physical activity play. In such settings, children often engage in vigorous, high-energy play that, at least on the surface, displays many similarities with serious predator chases and aggression. Although such activities have the potential for injury (usually when the partners get a bit too carried away), they are often accompanied by signs of enjoyment and positive affect, such as smiling, laughing, and bouncy, exaggerated motor movements. Parents, too, can get into the act -- chasing their child around the house or rolling on the floor in a bout of "Big Time Wrestling" with a partner a third their size.
Physical activity play is common in other animals as well. In fact, play-fighting and play-chasing are the major forms of social play observed among most mammals that play ( Fagen, 1981). Although biologists have had a hard time defining play-fighting or play-chasing, observers usually have little trouble identifying them and agreeing about when they occur (e.g., Miller, 1973). Because there are many similarities between play-fighting in animals and in humans, it is an excellent topic to begin our consideration of social play.
This section is made up of four chapters: two on play-fighting and two on locomotor play. The review is organized as in the previous section: The literature on nonhuman animals is considered before the literature on humans, and research on structure is reviewed before research on functions and effects.