Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2012;7(11):e46751.
doi: 10.1371/journal.pone.0046751. Epub 2012 Nov 7.

Oxytocin motivates non-cooperation in intergroup conflict to protect vulnerable in-group members

Carsten K W De Dreu  1 , Shaul Shalvi, Lindred L Greer, Gerben A Van Kleef, Michel J J Handgraaf
Affiliations

Oxytocin motivates non-cooperation in intergroup conflict to protect vulnerable in-group members

Carsten K W De Dreu et al. PLoS One. 2012.

Abstract

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.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Game Structures used in the Experiment.
(A). Between-Group Prisoner's Dilemma (BG-PD) with T(emptation)>R(eward)>P(unishment)>S(ucker); subscript IP (In-Group Player) are payoffs to the participant; subscript IG (In-Group) are payoffs to other in-group members; subscript OP (Out-group Player) are payoffs to the out-group protagonist; subscripts OG (Our-Group) are payoffs to other out-group members. Participant (row player) and Out-Group Player (column player) decide between coop (cooperation) and non-coop (non-cooperation); (B). Payoff Structure in the High Personal Vulnerability/High In-Group Vulnerability Condition; (C). Payoff Structure in the Low Personal Vulnerability/Low In-Group Vulnerability Condition; (D). Payoff Structure in the High Personal Vulnerability/Low In-Group Vulnerability Condition; (E). Payoff Structure in the Low Personal Vulnerability/Low In-Group Vulnerability Condition.
Figure 2
Figure 2. Non-Cooperation, In-Group Defending, and Excessive Non-Cooperation.
(A). Under low personal vulnerability, oxytocin produces more non-cooperation than placebo when in-group vulnerability is high rather than low (range 0–5, displayed ±SE). (B). Compared to placebo, oxytocin enhances motivation to defend the in-group when in-group vulnerability is high rather than low (based on N = 72; range 1–7, displayed ±SE). (C). Excessive non-cooperation (i.e., own non-cooperation>expected out-group non-cooperation; range −5 to +5; displayed ±SE) emerges under high in-group vulnerability when individuals received oxytocin rather than placebo.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Cohen T, Insko C (2008) War and peace: approaches to reducing intergroup conflict. Persp Psych Sci 3: 87–96. - PubMed
    1. Fiske ST (2002) What we know now about bias and intergroup conflict, the problem of the century. Curr Dir Psychol Sci 11: 123–128.
    1. Gingis J, Atran S (2011) War as imperative (not just practical politics by other means). Proc R Soc Biology 278: 2930–2938. - PMC - PubMed
    1. Bowles S (2009) Did warfare among ancestral hunter-gatherer groups affect the evolution of human social behaviors. Science 324: 1293–1298. - PubMed
    1. Manson JH, Wrangham RW (1991) Intergroup aggression in chimpanzees and humans. Curr Anthropology 32: 369–390.