[ Abstract / Highlights ]
Sanction enforcement offers the potential to mitigate free riding on punishment among multiple third parties. Cross-societal differences in the effectiveness of sanction enforcement may be explained by factors rooted in cultural evolution. This paper provides the first experiment to study third-party enforcement of punishment norms with and without opportunities for higher-order punishment by selecting two different societies in terms of the degree of ancestral kinship ties: India and the United Kingdom. In both societies, third parties strongly inflict punishment when they encounter a norm violation, and a third party’s failure to punish the norm violator invites higher-order punishment from their fellow third parties. These behavioral patterns are consistent with a model of social preferences and literature from anthropology and theoretical biology. On the other hand, two clear cross-societal variation emerges. First, third-party enforcement is stronger in the UK than in India. Parallel to this behavioral pattern, a supplementary survey also validates the conjecture that people in a society with looser ancestral kinship ties (the UK) are relatively more willing to engage in pro-social punishment. Second, intriguingly, the group size effect varies across the two societies: whereas third parties free ride on others’ punitive acts in the UK, they punish more when in the presence of other third parties in India.