@article {333775,
	title = {Human cooperation is strong among individuals but fragile between groups},
	journal = {Nature Reviews Psychology},
	year = {2026},
	month = {2026/06/12},
	abstract = {<p><meta charset="UTF-8" />Humans are often described as a cooperative species, and there is indeed a good deal of empirical support for this claim. However, there is also ample evidence of distrust, hostility and aggression. In\&nbsp;this Perspective, we draw on the decades-long literature of human cooperation to reconcile this conflicting evidence. Specifically, we advance a theoretical model that suggests that individuals frequently engage cooperatively with other individuals, but that cooperation between groups is more fragile. We further outline that, compared to groups, cooperation in dyads is often more easily achieved through three complementary mechanisms: reciprocity, empathy and psychological safety. Conversely, cooperation is rare between groups because individuals often hold some intuition-based mistrust towards outgroup members that motivates ingroup favouritism, which can turn into evidence-based distrust following experiences of parochialism by outgroups. When groups are negatively interdependent and perceive outgroup threat, intergroup relations can further deteriorate into conflict characterized by hostility and sometimes even hate. We conclude by outlining the implications of this model for improving intergroup relations.</p>
},
	isbn = {2731-0574},
	doi = {http://dx.doi.org/10.1038/s44159-026-00580-z},
	url = {https://www.nature.com/articles/s44159-026-00580-z},
	author = {Van Lange, Paul A. M. and Bergmann, Paul K.}
}
