Giving Leads to Happiness in Young Children Lara B. Aknin*, J. Kiley Hamlin, Elizabeth W. Dunn Psychology Department, University of British Columbia, Vancouver, British Columbia, Canada Abstract Evolutionary models of cooperation require proximate mechanisms that sustain prosociality despite inherent costs to individuals. The ‘‘warm glow’’ that often follows prosocial acts could provide one such mechanism; if so, these emotional benefits may be observable very early in development. Consistent with this hypothesis, the present study finds that before the age of two, toddlers exhibit greater happiness when giving treats to others than receiving treats themselves. Further, children are happier after engaging in costly giving – forfeiting their own resources – than when giving the same treat at no cost. By documenting the emotionally rewarding properties of costly prosocial behavior among toddlers, this research provides initial support for the claim that experiencing positive emotions when giving to others is a proximate mechanism for human cooperation. Citation: Aknin LB, Hamlin JK, Dunn EW (2012) Giving Leads to Happiness in Young Children. PLoS ONE 7(6): e39211. doi:10.1371/journal.pone.0039211 Editor: Andrew H. Kemp, University of Sydney, Australia Received March 5, 2012; Accepted May 21, 2012; Published June 14, 2012 Copyright: 2012 Aknin et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This research was supported by a grant awarded to the second author from the Social Sciences and Humanities Research Council of Canada (410-2011- 0780; Granting agency website http://www.sshrc-crsh.gc.ca/home-accueil-eng.aspx). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: laknin@psych.ubc.ca Introduction Contrary to traditional economic theory that depicts human beings as fundamentally motivated by self-interest, people routinely engage in cooperative acts—from giving blood to donating to charity—that require them to incur personal costs for the benefit of others. Indeed, human survival and flourishing have depended on our species’ ability to work together to achieve feats that could not be achieved alone, such as hunting large prey and building shelter in inhospitable regions [1]. These behaviors present a puzzle that has intrigued social scientists for decades: whereas cooperation is beneficial once established at a population level [2–9], cooperation frequently requires that individuals engage in prosocial acts, facing a loss of resources and potential physical harm. What inspires and sustains such costly tendencies in individuals? The prosocial behaviors that underlie cooperation could be supported entirely by cultural mechanisms, such as explicit teaching and the imitation of prominent role models. Although socialization almost certainly plays an important role in supporting human prosociality, this process may be complemented by an evolved proclivity for human beings to find prosocial behavior ‘‘self-rewarding.’’ Indeed, behaviors that are associated with positive emotions are more likely to be repeated [10], providing a powerful proximate mechanism that could sustain prosocial behavior even among individuals who are not fully socialized. Supporting the possibility that humans may have evolved to find generous acts rewarding, adults from around the world report higher levels of happiness when spending money on others than when spending money on themselves [11,12], and giving money to charity activates regions of the brain associated with processing reward [13–15]. Moreover, interventions encouraging participants to engage in acts of kindness have been shown to increase well- being among adults [16,17]. Indeed, despite lay conceptions that children are inherently selfish [18–20], even young children engage in prosocial behavior: toddlers attempt to comfort individuals in distress [21], and assist others in achieving their goals, even at cost to themselves [22,23]. Although these results are consistent with the hypothesis that giving to others is inherently rewarding for young children, no research has directly tested this central premise or explored the ontogenetic origins of the relationship between giving and happiness. Here, we investigate whether children under the age of two experience greater happiness when giving treats to others rather than receiving treats themselves. In addition, because forms of giving that require individuals to forfeit their own resources should be the most difficult to sustain, we examine whether children are happier when engaging in costly giving than when giving the same resource at no personal cost. As an initial test of the hypothesis that giving produces emotional benefits among young children, we examined past studies from our lab, in which toddlers played a social game that did or did not involve giving. Emotional expressions were videotaped and coded by two trained assistants (blind to hypotheses) for happiness on a seven-point scale (1-not at all happy; 7– very happy, a = .92); naive coder ratings have been shown to correlate highly (r..95) with other validated measures of emotional coding, such as Baby FACS [24]. Specifically, twenty- three toddlers either (1) shared a toy with a puppet, to which the puppet responded positively, or (2) activated an appealing animal- sound toy that a puppet had taught them to use, to which the puppet responded positively; interactions with puppets are commonly used to provide a controlled but engaging situation for studying young children’s moral behavior [25,26]. Consistent with the hypothesis that giving is emotionally rewarding in young children, toddlers who shared a toy with a puppet displayed greater happiness than toddlers who interacted with a toy and a puppet (Analysis of Variance (ANOVA) F(1,21) = 6.13, p,0.03, d = 1.02, Figure 1). Although these studies were not designed to PLoS ONE | www.plosone.org 1 June 2012 | Volume 7 | Issue 6 | e39211