title: Children, but not chimpanzees, have facial correlates of determination.
abstract: Facial expressions have long been proposed to be important agents in forming and maintaining cooperative interactions in social groups. Human beings are inordinately cooperative when compared with their closest-living relatives, the great apes, and hence one might expect species differences in facial expressivity in contexts in which cooperation could be advantageous. Here, human children and chimpanzees were given an identical task designed to induce an element of frustration (it was impossible to solve). In children, but not chimpanzees, facial expressions associated with effort and determination positively correlated with persistence at the task. By contrast, bodily indicators of stress (self-directed behaviour) negatively correlated with task persistence in chimpanzees. Thus, children exhibited more behaviour as they persisted, and chimpanzees exhibited less. The facial expressions produced by children, could, therefore, function to solicit prosocial assistance from others.
authors.affiliation: Centre for Comparative and Evolutionary Psychology, University of Portsmouth, , Portsmouth PO1 2DY, UK.
authors.forename: B M
authors.initials: BM
authors.lastname: Waller
authors.forename: A
authors.initials: A
authors.lastname: Misch
authors.forename: J
authors.initials: J
authors.lastname: Whitehouse
authors.forename: E
authors.initials: E
authors.lastname: Herrmann
mesh_terms: D000786:Anger; D000818:Animals; D000836:Animals, Zoo / Q000523:psychology*; D002648:Child; D002675:Child, Preschool; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D002679:Pan troglodytes / Q000523:psychology*; D012201:Reward
keywords: cooperation; determination; emotion; facial action coding system; facial expression; frustration