TY  - JOUR
PY  - 2022//
TI  - Environmental stress increases out-group aggression and intergroup conflict in humans
JO  - Philosophical transactions of the Royal Society of London. Series B, Biological sciences
A1  - de Dreu, Carsten K. W.
A1  - Gross, Jörg
A1  - Reddmann, Lennart
SP  - e20210147
EP  - e20210147
VL  - 377
IS  - 1851
N2  - Peaceful coexistence and trade among human groups can be fragile and intergroup relations frequently transition to violent exchange and conflict. Here we specify how exogenous changes in groups' environment and ensuing carrying-capacity stress can increase individual participation in intergroup conflict, and out-group aggression in particular. In two intergroup contest experiments, individuals could contribute private resources to out-group aggression (versus in-group defense). Environmental unpredictability, induced by making non-invested resources subject to risk of destruction (versus not), created psychological stress and increased participation in and coordination of out-group attacks. Archival analyses of interstate conflicts showed, likewise, that sovereign states engage in revisionist warfare more when their pre-conflict economic and climatic environment were more volatile and unpredictable. Given that participation in conflict is wasteful, environmental unpredictability not only made groups more often victorious but also less wealthy. Macro-level changes in the natural and economic environment can be a root cause of out-group aggression and turn benign intergroup relations violent. This article is part of the theme issue 'Intergroup conflict across taxa'.<p />  <p>Language: en</p>
LA  - en
SN  - 0962-8436
UR  - http://dx.doi.org/10.1098/rstb.2021.0147
ID  - ref1
ER  -