Restraint is thought to be essential to enable the reciprocity needed for play fighting to remain playful. Descriptions of playing in pigs suggest that they do not exhibit restraint. Analysis of videotaped sequences of play fighting in captive family groups of warty pigs was used to test three hypotheses about restraint and reciprocity. Hypothesis 1 asserts that the lack of restraint arises from neither participant handicapping its actions in favour of its opponent: this was supported. Hypothesis 2 asserts that the winner of a contest will show restraint by not prosecuting further attack: this was not supported. However, the winner did refrain from attacking if the loser signalled submission. Hypothesis 3 asserts that restraint by the winner will allow reciprocal attacks by the loser – this was supported. The dissociation of restraint and reciprocity evident in the pigs offers some new insights into the evolution of play fighting. © 2016 Copyright 2016 by Koninklijke Brill NV, Leiden, The Netherlands.
play fighting in Visayan warty pigs (Sus cebifrons): Insights on restraint and reciprocity in the maintenance of play
