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Temperature and outgroup discrimination

Published online by Cambridge University Press:  03 May 2021

Donghyun Danny Choi
Political Science, University of Pittsburgh, Pittsburgh, PA 15260, USA
Mathias Poertner
International Affairs, Bush School of Government and Public Service, Texas A&M University, College Station, TX 77843, USA
Nicholas Sambanis*
Political Science and Director, Identity and Conflict Lab, University of Pennsylvania, Philadelphia, PA 19104, USA
*Corresponding author. Email:


High temperatures have been linked to aggression and different forms of conflict in humans. We consider whether exposure to heat waves increases discriminatory behavior toward outgroups. Using data from two large-scale field experiments in Germany, we find a direct causal effect of exposure to heat shocks on discrimination in helping behavior. As temperature rises, German natives faced with a choice to provide help to strangers in every-day interactions help Muslim immigrants less than they do other German natives, while help rates toward natives are unaffected by temperature. This finding suggests that there may be a physiological basis for discriminatory behavior toward outgroups.

Research Note
Copyright © The Author(s), 2021. Published by Cambridge University Press on behalf of the European Political Science Association

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All authors contributed equally to this work; their names are listed alphabetically.


Aarøe, L, Petersen, MB and Arceneaux, K (2017) The behavioral immune system shapes political intuitions: why and how individual differences in disgust sensitivity underlie opposition to immigration. American Political Science Review 111, 277294.CrossRefGoogle Scholar
Anderson, CA (2001) Heat and violence. Current Directions in Psychological Science 10, 3338.CrossRefGoogle Scholar
Avenanti, A, Sirigu, A and Aglioti, S (2010) Racial bias reduces empathic sensorimotor resonance with other-race pain. Current Biology 20, 10181022.CrossRefGoogle ScholarPubMed
Balafoutas, L, Nikiforakis, N and Rockenbach, B (2014) Direct and indirect punishment among strangers in the field. Proceedings of the National Academy of Sciences 111, 1592415927.CrossRefGoogle ScholarPubMed
Belkin, LY and Kouchaki, M (2017) Too hot to help! exploring the impact of ambient temperature on helping. European Journal of Social Psychology 47, 525538.CrossRefGoogle Scholar
Benson, P, Karabenick, S and Lerner, R (1976) Pretty pleases: the effects of physical attractiveness, race, and sex on receiving help. Journal of Experimental Social Psychology 12, 409415.CrossRefGoogle Scholar
Bickman, L and Kamzan, M (1973) The effect of race and need on helping behavior. Journal of Social Psychology 89, 7377.CrossRefGoogle Scholar
Bowles, S (2006) Group competition, reproductive leveling, and the evolution of human altruism. Science 314, 15691572.Google ScholarPubMed
Bowles, S and Choi, J-K (2007) The coevolution of parochial altruism and war. Science 318, 636640.26 OctoberGoogle Scholar
Burke, M, Hsiang, SM and Miguel, E (2015) Climate and conflict. Annual Review of Economics 7, 577617.CrossRefGoogle Scholar
Choi, DD, Poertner, M and Sambanis, N (2019) Parochialism, social norms, and discrimination against immigrants. Proceedings of the National Academy of Sciences 116, 1627416279.CrossRefGoogle ScholarPubMed
De Dreu, CK, Greer, LL, Handgraaf, MJ, Shalvi, S, Van Kleef, GA, Baas, M, Ten Velden, FS, Van Dijk, E and Feith, SW (2010) The neuropeptide oxytocin regulates parochial altruism in intergroup conflict among humans. Science 328, 14081411.CrossRefGoogle ScholarPubMed
House, BR, Silk, JB, Henrich, JH, Barretta, C, Scelzaa, BA, Boyette, AH, Hewlett, BS, McElreathe, R and Laurence, S (2012). Ontogeny of prosocial behavior across diverse societies. Proceedings of the National Academy of Sciences 110, 1458614591.Google Scholar
Hruschka, DJ and Henrich, J (2013). Economic and evolutionary hypotheses for cross-population variation in parochialism. Frontiers in Human Neuroscience 7, 110.CrossRefGoogle ScholarPubMed
Johnson, ZV and Young, LJ (2017). Oxytocin and vasopressin neural networks: implications for social behavioral diversity and translational neuroscience. Neuroscience and Biobehavior Reviews 76, 8798.CrossRefGoogle ScholarPubMed
Kachelmann, J (2020). Temperaturentwicklung in Deutschland seit (1881). chland-seit-1881/ [Accessed: 2020-04-20].Google Scholar
Kang, Y, Williams, LE, Clark, MS, Gray, JR and Bargh, JA (2011). Physical temperature effects on trust behavior: the role of insula. Social Cognitive and Affective Neuroscience 6, 507515.CrossRefGoogle ScholarPubMed
Kramer, B (2019). Wann Schüler Hitzefrei bekommen. Süddeutsche Zeitung June 26, 2019.Google Scholar
Piliavin, I, Rodin, J and Piliavin, J (1969). Good samaritanism: an underground phenomenon? Journal of Personality and Social Psychology 13, 289299.CrossRefGoogle ScholarPubMed
RTL (2020). Klima für Deutschland - Mittleres Temperaturmaximum. [Accessed: 2020-04-20].Google Scholar
Saucier, D, Miller, C and Doucet, N (2005). Differences in helping whites and blacks: a meta-analysis. Personality and Social Psychology Review 9, 216.CrossRefGoogle ScholarPubMed
Saucier, DA, McManus, JL and Smith, SJ (2010) Discrimination against out-group members in helping situations. In Sturmer, S and Snyder, M (eds.), The Psychology of Prosocial Behavior. Hoboken, NJ: Wiley-Blackwell, pp. 103120.Google Scholar
Shalvi, S and De Dreu, CKW (2014). Oxytocin promotes group-serving dishonesty. PNAS 111, 55035507.CrossRefGoogle ScholarPubMed
Sheng, F and Han, S (2012). Manipulations of cognitive strategies and intergroup relationships reduce the racial bias in empathic neural responses. NeuroImage 61, 786789.CrossRefGoogle ScholarPubMed
Van de Vliert, E and Postmes, T (2012). Climato-economic livability predicts societal collectivism and political autocracy better than parasitic stress does. Behavioral Brain Science 35, 9495.CrossRefGoogle Scholar
Xu, X, Zuo, X, Wang, X and Han, S (2009). Do you feel my pain? Racial group membership modulates empathic neural responses. Journal of Neuroscience 29, 85258529.CrossRefGoogle Scholar
Yong-Lu, Y and Gordon, CJ (2002). Possible role of vasopressin in the thermoregulatory response to chlorpyrifos in the rat. Pharmacology and Toxicology 90, 311316.CrossRefGoogle Scholar
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