Inequity aversion in primates: the role of social and internal standards
Year: 2025
Type: preprint
Abstract: Inequity aversion, a discomfort experienced when outcomes are judged as unfair, is a fundamental yet still enigmatic driver of primate behaviour. Often costly in the short term, it has been proposed as one of the key mechanisms of the evolution of cooperation in humans and other social primates. However, despite two decades of research on non-human primates, empirical evidence for inequity aversion across species remains highly variable. Some studies have reported clear aversive responses to inequitable situations while others have failed to reproduce such findings. This inconsistency reflects both methodological variability and conceptual challenges, with the confounding presence of non-social processes such as frustration, expectation violation or loss aversion often believed to be more parsimonious explanations for some of the results obtained. This review synthesises findings from various paradigms (from token exchange to cooperative and choice-based tasks), investigating inequity aversion through a critical lens on its very definition. It explores whether this mechanism, traditionally regarded as inherently social, might also arise from discrepancies between one's own effort and reward. Considering both social and internal standards as potential drivers of inequity aversion, this work questions if a broader definition might help reconcile some of the conflicting results and offer new insights on the evolution of fairness.
Source: HAL
Language: English
Topic: Primate Behavior and Ecology
Domain: Life Sciences
SDG: Reduced inequalities
Open Access status: green
OpenAlex ID: W4417342556