Culture and group-functional punishment behaviour Espín Martín, Antonio Manuel Brañas Garza, Pablo Gamella Mora, Juan Francisco Herrmann, Benedikt Martín Rodríguez, Jesús Cooperation punishment Gypsy/Roma Culture Evolution Funding. Financial support from the Spanish Ministry of Science and Innovation (PGC2018-093506-B-I00, ECO2013-44879-R) and theRegionalGovernment ofAndalusia (PY18-FR-0007, P11-SEJ-8286 and P12-SEJ-1436) is gratefully acknowledged.Antonio Espín acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 754446 and UGR Research and Knowledge Transfer Fund – Athenea3i. Funding for open access charge: Universidad de Granada. Data availability statement. The dataset and code (STATA) are available at: http://hdl.handle.net/10481/76057 Supplementary material. To view supplementary material for this article, please visit https://doi.org/10.1017/ehs.2022.32 Humans often ‘altruistically’ punish non-cooperators in one-shot interactions among genetically unrelated individuals. This poses an evolutionary puzzle because altruistic punishment enforces cooperation norms that benefit the whole group but is costly for the punisher. One key explanation is that punishment follows a social-benefits logic: it is eminently normative and group-functional (drawing on cultural group selection theories). In contrast, mismatch-based deterrence theory argues that punishment serves the individual- level function of deterring mistreatment of oneself and one’s allies, hinging upon the evolved human coalitional psychology. We conducted multilateral-cooperation experiments with a sample of Spanish Romani people (Gitanos or Calé) and the non-Gitano majority. The Gitanos represent a unique case study because they rely heavily on close kin-based networks and display a strong ethnic identity. We find that Gitano non-cooperators were not punished by co-ethnics in only-Gitano (ethnically) homogeneous groups but were harshly punished by other Gitanos and by non-Gitanos in ethnically mixed groups. Our findings suggest the existence of culture-specific motives for punishment: Gitanos, especially males, appear to use punishment to protect their ethnic identity, whereas non-Gitanos use punishment to protect a norm of universal cooperation. Only theories that consider normative, group-functional forces underlying punishment behaviour can explain our data. 2022-10-17T09:24:02Z 2022-10-17T09:24:02Z 2022-08-01 journal article Espín, A., Brañas-Garza, P., Gamella, J., Herrmann, B., & Martín, J. (2022). Culture and group-functional punishment behaviour. Evolutionary Human Sciences, 4, E35. [doi:10.1017/ehs.2022.32] https://hdl.handle.net/10481/77350 10.1017/ehs.2022.32 eng info:eu-repo/grantAgreement/EC/H2020/754446 http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional Cambridge University Press