6 Buttelmann,Bobm member,and 13%and 35%of the items to the box.These The current study leaves some questions unanswered differences indicated an even larger gender gap in in- y,itis undand characteristics of control for .D- resources and avoid negative resources and that the chil Discussion dren's allocations would not result in any personal gains Our aim in the cu hether dy.we used fict ow an in-group biasnl we rav nd wanted to find out what motivations underlie in-group of our participants,future research should indlude real biased behavior among children.We developed a new outcomes.For instance,one could provide recipients with an endowment (of,e.g.candy)that may increase 5mnatebeteenpost and ain)as of group hate.Both age groups showed a clear in-group lly.th be different motivations that underlie the conception of bias in both domains of resources,positive and negative out-group hate:to absolutely harm the out-group or to the relative een the in-group relative to distir and out-group hate were able to serve as a behavioral the distinction between competitiveness and pure ham motivation (i.e.,in the allocation of positive resources). on a behavioral level may be a direction for future intergroup discrimination research. o-year whicl even str of the obtained findin was excluded as a potential source of this effect (ie in the allocation of negative resources),we found out-group societies.However.intragroup cooperation can sacrifice hate to be a behavioral motivation for inte oup collective efficiency if the aim is to harm other groups to criminati 8-year-on flict (Bohm Roc rely damaged by engagingin long-lasting inte harmed the out-group by giving the majority of negative conflicts.Given that our results suggest not only that in group love and out-group hate are independent of each box (ie ane but that group love emerges in human in-group p e motivati quences for one's own group constitute the foundation of humans'inherent prosocial nature.Children,and in par. in-group bias and discrimination,whereas the negative ticular boys.should be taught as early as prescho ol age groups ecom behavioral nd loyalty are valuable an t is intere in the lon ticular showed out-group hate.From an evolutionary tion at the same time. perspective,there are good reasons for why males are more prone em les to ngage in Author Contributions be reinforced through cultural processes.This gender gap is also consistent with other research findings that have indi mainly boys who show paroc Acknowledgments hat dif ences (ie..out-group hate)between boys and girls may at least partially,contribute to a gender gap in children's thank M.Pigors for valuable advice on technical implementa6 Buttelmann, Böhm member, and 13% and 35% of the items to the box. These differences indicated an even larger gender gap in in￾group bias when motivated by pure out-group hate, Mann-Whitney U = 58.00, p = .002, r = .53. Discussion Our aim in the current study was to investigate whether 6- and 8-year-olds show an in-group bias in their alloca￾tion of positive and negative resources. Specifically, we wanted to find out what motivations underlie in-group￾biased behavior among children. We developed a new experimental game based on a behavioral measure that allowed us to discriminate between positive and negative group-based preferences, that is, in-group love and out￾group hate. Both age groups showed a clear in-group bias in both domains of resources, positive and negative. With regard to the underlying motivations, however, our results showed a primacy of in-group love relative to out￾group hate in human ontogeny. When both in-group love and out-group hate were able to serve as a behavioral motivation (i.e., in the allocation of positive resources), there was already substantial intergroup discrimination among the 6-year-olds, which became even stronger among the 8-year-olds. In contrast, when in-group love was excluded as a potential source of this effect (i.e., in the allocation of negative resources), we found out-group hate to be a behavioral motivation for intergroup dis￾crimination among the 8-year-olds only. Whereas the younger children only prevented their in-group from receiving negative items, the older children intentionally harmed the out-group by giving the majority of negative items to the out-group rather than putting them in the neutral box (i.e., an egalitarian allocation). Thus, we con￾clude that in-group love develops before out-group hate in human ontogeny. Accordingly, the positive conse￾quences for one’s own group constitute the foundation of in-group bias and discrimination, whereas the negative consequences for other groups become a behavioral motivation only at a later stage in human development. It is interesting that among 8-year-olds, boys in par￾ticular showed out-group hate. From an evolutionary perspective, there are good reasons for why males are more prone than are females to engage in competitive intergroup conflict (e.g., the male-warrior hypothesis; Van Vugt, De Cremer, & Janssen, 2007), which is likely to be reinforced through cultural processes. This gender gap is also consistent with other research findings that have indicated that it is mainly boys who show parochial altruism (Fehr et al., 2008). Our study, however, provides the first evidence that differences in group-based prefer￾ences (i.e., out-group hate) between boys and girls may, at least partially, contribute to a gender gap in children’s competitive orientation (e.g., Gneezy & Rustichini, 2004; Moely, Skarin, & Weft, 1979). The current study leaves some questions unanswered. Specifically, it is unclear whether we were able to exclude or control for all of the demand characteristics of our task. We tried to keep them as low as possible by making it clear that both puppets would like to receive positive resources and avoid negative resources and that the chil￾dren’s allocations would not result in any personal gains or losses. Furthermore, in the current study, we used ficti￾tious instead of real outcomes. Although we have argued that this should not be a problem for children at the ages of our participants, future research should include real outcomes. For instance, one could provide recipients with an endowment (of, e.g., candy) that may increase (positive domain) or decrease (negative domain) as a function of participants’ allocations. Finally, there might be different motivations that underlie the conception of out-group hate: to absolutely harm the out-group or to maximize the relative difference between the in-group and the out-group. Until now, these differences in moti￾vation have not been distinguished empirically. Refining the distinction between competitiveness and pure harm on a behavioral level may be a direction for future research. The implications of the obtained findings are far￾reaching. The increase of cooperation and solidarity within groups clearly is of utmost importance for human societies. However, intragroup cooperation can sacrifice collective efficiency if the aim is to harm other groups to win an intergroup conflict (Böhm & Rockenbach, 2013). An in-group’s absolute welfare, in particular, can be severely damaged by engaging in long-lasting intergroup conflicts. Given that our results suggest not only that in￾group love and out-group hate are independent of each other but also that in-group love emerges before out￾group hate in human development, it is possible to affect both of these motivations separately by building on humans’ inherent prosocial nature. Children, and in par￾ticular boys, should be taught as early as preschool age that intragroup cooperation and loyalty are valuable and beneficial for humanity, and even for their own group in the long run, only if they do not imply out-group deroga￾tion at the same time. Author Contributions D. Buttelmann and R. Böhm designed the study and collected the data. D. Buttelmann analyzed the data. Both authors drafted the manuscript and approved the final version of the manu￾script for submission. Acknowledgments The authors are grateful to their students M. Aßmann, I. Dübner, and K. Gerst, who provided excellent research assistance. We thank M. Pigors for valuable advice on technical implementa￾tion, the research group at the Center for Empirical Research in Economics and Behavioral Sciences for inspiring discussions, Downloaded from pss.sagepub.com by Cai Xing on February 13, 2014