Self-Handicapping Play in Mountain Gorillas (Gorilla beringei beringei): How Play Stimulates Emotional Regulation

Abstract

Play is sometimes considered frivolous and non-functional. Yet social play provides important ontogenetic opportunities for animals to socialize and regulate their behavior in a relaxed setting. Mountain gorillas are shown to self-handicap play behavior in specific contexts. Self-handicapping through movement restriction and to a lesser extent positional vulnerability are mediated by individual size and play pair type (i.e. dyads matched or mismatched in size). Within pairs of mismatched sizes, play behavior significantly differed between small and large subjects. Dyads of matched small players show greater degrees of movement restriction and positional vulnerability compared to mismatched dyads. Large partners highly restrict movement with small partners but do not do so with similarly sized partners. The interactive effect between individual size and pair type greatly impact the degree of self-handicapping in mountain gorillas. Benefits related to emotional regulation through play are discussed.