What is play fighting and what is it good for?

Play fighting is a common form of play reported among species of mammals, birds, and some other taxa. The competition present in play fighting revolves around gaining some advantage, such as biting a partner without being bitten. The behavior simulated during play fighting need not be restricted to that present in adult serious fighting, but can involve competitive interactions derived from amicable behavior, such as sex and social grooming, or from nonsocial competition, such as predation. What unifies play fighting, irrespective of the functional behavior being simulated, is that it involves some degree of reciprocity, or turn taking, that requires that the competition be attenuated by cooperation. However, there are several different ways in which cooperation can be inserted into playful interactions, and these vary in use across different species. The moderation of competition with cooperation forces animals to monitor their own actions and those of their partners, and this common feature appears to be one vehicle through which the experience of play fighting in the juvenile period can train animals for greater psychological resilience. The monitoring and contextual adjustment of actions influences the development of executive functions of the brain, which, in turn, leads to the development of more adaptable adults.