Juvenile rhesus macaques (Macaca mulatta) dramatically increased their reconciliation rates after being transferred into a group of the more conciliatory stumptail macaques (Macaca arctoides).
Notes on verification
This is a well-established finding from de Waal & Johnson (1986) and subsequent work (de Waal, PNAS 1993 'Cultural transmission of a social custom'), widely cited in primatology as evidence for social learning of conflict-resolution behavior across species. Multiple independent citations corroborate the core finding, though exact wording ('dramatically') may vary by source. [tier=silver indep_score=0.77 clusters=2 claim_tier=notable]
Sources
- Social dynamics of vervet monkeys are dependent upon group identity (seed:psychology_and_neuroscience)
- https://www.nature.com/articles/351001a0 (corroboration)
- https://www.pnas.org/doi/10.1073/pnas.87.13.5111 (corroboration)