title: Sex differences in in-group cooperation vary dynamically with competitive conditions and outcomes.
abstract: Men's but not women's investment in a public goods game varied dynamically with the presence or absence of a perceived out-group. Three hundred fifty-four (167 male) young adults participated in multiple iterations of a public goods game under intergroup and individual competition conditions. Participants received feedback about whether their investments in the group were sufficient to earn a bonus to be shared among all in-group members. Results for the first trial confirm previous research in which men's but not women's investments were higher when there was a competing out-group. We extended these findings by showing that men's investment in the in-group varied dynamically by condition depending on the outcome of the previous trial: In the group condition, men, but not women, decreased spending following a win (i.e., earning an in-group bonus). In the individual condition, men, but not women, increased spending following a win. We hypothesize that these patterns reflect a male bias to calibrate their level of in-group investment such that they sacrifice only what is necessary for their group to successfully compete against a rival group.
authors: Department of Psychological Sciences, University of Missouri, Columbia, USA. dhbd45@mail.missouri.edu
authors: Drew H
authors: DH
authors: Bailey
authors: Benjamin
authors: B
authors: Winegard
authors: Jon
authors: J
authors: Oxford
authors: David C
authors: DC
authors: Geary
mesh_terms: D003163:Competitive Behavior; D003299:Cooperative Behavior; D005260:Female; D005717:Games, Experimental; D006126:Group Processes; D006801:Humans; D007206:Individuality; D007398:Interpersonal Relations; D008297:Male; D008399:Mass Behavior; D011582:Psychological Theory; D012201:Reward; D012380:Role; D012727:Sex Characteristics; D012938:Social Perception; D055815:Young Adult