title: Children reject inequity out of spite.
abstract: When confronted with inequality, human children and adults sacrifice personal gain to reduce the pay-offs of other individuals, exhibiting apparently spiteful motivations. By contrast, sacrifice of personal gain by non-human animals is often interpreted as frustration. Spite may thus be a uniquely human motivator. However, to date, no empirical study has demonstrated that psychological spite actually drives human behaviour, leaving the motivation for inequity aversion unclear. Here, we ask whether 4- to 9-year-old children and adults reject disadvantageous inequity (less for self, more for peer) out of spite or frustration. We show that children, but not adults, are more likely to reject disadvantageous allocations when doing so deprives their peer of a better reward (spite) than when their peer has already received the better reward (frustration). Spiteful motivations are thus present early in childhood and may be a species-specific component of humans' developing cooperative and competitive behaviour.
authors.affiliation: Department of Psychology, Yale University, New Haven, CT 06520-8205, USA Department of Psychology, Harvard University, Cambridge, MA 02138, USA katherine.mcauliffe@yale.edu.
authors.forename: Katherine
authors.initials: K
authors.lastname: McAuliffe
authors.affiliation: Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Blake
authors.affiliation: Department of Psychology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Felix
authors.initials: F
authors.lastname: Warneken
mesh_terms: D002648:Child; D006801:Humans; D012935:Social Justice
keywords: cooperation; fairness; frustration; inequity aversion; social cognition; spite