http://repub.eur.nl/res/aut/288/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/37906/ 2012-11-07T00:00:00Z Intergroup conflict is often driven by an individual's motivation to protect oneself and fellow group members against the threat of out-group aggression, including the tendency to pre-empt out-group threat through a competitive approach. Here we link such defense-motivated competition to oxytocin, a hypothalamic neuropeptide involved in reproduction and social bonding. An intergroup conflict game was developed to disentangle whether oxytocin motivates competitive approach to protect (i) immediate self-interest, (ii) vulnerable in-group members, or (iii) both. Males self-administered oxytocin or placebo (double-blind placebo-controlled) and made decisions with financial consequences to themselves, their fellow in-group members, and a competing out-group. Game payoffs were manipulated between-subjects so that non-cooperation by the out-group had high vs. low impact on personal payoff (personal vulnerability), and high vs. low impact on payoff to fellow in-group members (in-group vulnerability). When personal vulnerability was high, non-cooperation was unaffected by treatment and in-group vulnerability. When personal vulnerability was low, however, in-group vulnerability motivated non-cooperation but only when males received oxytocin. Oxytocin fuels a defense-motivated competitive approach to protect vulnerable group members, even when personal fate is not at stake. http://repub.eur.nl/res/pub/37901/ 2012-03-22T00:00:00Z In intergroup competition and conflict, humans benefit from coalitions with strong partners who help them to protect their in-group and prevail over competing out-groups. Here, we link oxytocin, a neuropeptide produced in the hypothalamus, to ally selection in intergroup competition. In a double-blind placebocontrolled experiment, males self-administered oxytocin or placebo, and made selection decisions about six high-threat and six low-threat targets as potential allies in intergroup competition. Males given oxytocin rather than placebo viewed high-threat targets as more useful allies and more frequently selected them into their team than low-threat targets. http://repub.eur.nl/res/pub/21519/ 2010-11-01T00:00:00Z This study explores the role of intragroup dynamics in intergroup conflict. In a computer-mediated negotiation experiment (N = 107), we investigated how a group representative's standing in the group, group norm, and the representative's need to belong influence behavior in intergroup negotiations. We hypothesized that the extent to which peripheral representatives adhere to group norms is contingent on their need to belong, whereas prototypical representatives behave in norm-congruent ways regardless of their need to belong. In support of this idea, results showed that prototypicals behaved more cooperatively when the group norm prescribed cooperation rather than competition. By contrast, peripherals only adhered to the group norm when they had a high need to belong. These findings suggest that peripherals only represent the interests of their group when doing so furthers their self-interest. We discuss implications for theorizing about prototypicality, social exclusion, and conformity to group norms. http://repub.eur.nl/res/pub/20952/ 2009-10-01T00:00:00Z The present research examined whether the emotions of others (i.e., disappointment versus happiness with respect to a received outcome) influence own self-esteem when being overpaid. Results from two experiments demonstrated that participants reported higher performance self-esteem when the other expressed happiness rather than disappointment. This effect was only found in the condition where one was overpaid relative to the condition where one did not yet know one’s own outcome. In the second experimental study we further found that this interaction between the emotion of the other and the distribution situation only emerged among participants low (relative to high) in personal need for structure. Implications with respect to the relationship between overpayment and self-esteem and the interpersonal effects of emotions in this process are discussed. http://repub.eur.nl/res/pub/19926/ 2009-06-01T00:00:00Z We examined how leader emotional displays affect team performance. We developed and tested the idea that effects of leader displays of anger versus happiness depend on followers' epistemic motivation, which is the desire to develop a thorough understanding of a situation. Experimental data on four-person teams engaged in an interdependent team task showed that teams with higher epistemic motivation performed better when their leaders displayed anger (mediated by team members' performance inferences), whereas teams with lower epistemic motivation performed better when the leaders expressed happiness (mediated by team members' affective reactions). Theoretical contributions and managerial ramifications are discussed. http://repub.eur.nl/res/pub/8496/ 2006-09-01T00:00:00Z Although there are numerous potential benefits to diversity in work groups, converging dimensions of diversity often prevent groups from exploiting this potential. In a study of heterogeneous decision-making groups, we examined whether the disruptive effects of diversity faultlines can be overcome by convincing groups of the value in diversity. Groups were either persuaded of the value of diversity or of the value of similarity for group performance, and they were provided with either homogeneous or heterogeneous information. As expected, informationally diverse groups performed better when they held pro-diversity rather than pro-similarity beliefs, whereas the performance of informationally homogeneous groups was unaffected by diversity beliefs. This effect was mediated by group-level information elaboration. Implications for diversity management in organizations are discussed. http://repub.eur.nl/res/pub/8502/ 2006-08-01T00:00:00Z How does a representative's position in the group influence behaviour in intergroup negotiation? Applying insights from the social identity approach (specifically self-categorization theory), the effects of group member prototypicality, accountability, and group attractiveness on competitiveness in intergroup bargaining were examined. As representatives of their group, participants engaged in a computer-mediated negotiation with a simulated outgroup opponent. In Exp. 1 (N = 114), representatives with a peripheral status in the group sent more competitive and fewer cooperative messages to the opponent than did prototypical representatives, but only under accountability. Exp. 2 (N = 110) replicated this finding, and showed that, under accountability, peripherals also made higher demands than did prototypicals, but only when group membership was perceived as attractive. Results are discussed in relation to impression management and strategic behaviour. http://repub.eur.nl/res/pub/8500/ 2006-01-01T00:00:00Z We conducted an experiment to show how the interplay between informational diversity and other dimensions of diversity can account for some of the inconsistent effects of informational diversity in previous research. 70 four-person groups involved in a decision-making task received homogeneous or heterogeneous information. By manipulating gender composition and bogus personality feedback we created groups that either had a potential faultline (a basis for subgroup categorization) or were homogeneous on these dimensions. In potential faultline groups, heterogeneity of information either converged with or cross-cut the other dimensions of diversity. Results showed that informational diversity enhanced group functioning when it was crossed rather than converged with the potential faultline.