Punitive justice serves to restore reciprocal cooperation in three small-scale societies.

Fines, corporal punishments, and other procedures of punitive justice recur across small-scale societies. Although they are often assumed to enforce group norms, we here propose the relation-restoration hypothesis of punitive justice, according to which punitive procedures function to restore dyadic cooperation and curtail conflict between offender and victim following violations of reciprocal obligations. We test this hypothesis's predictions using observations of justice systems in three small-scale societies. We code ethnographic reports of 97 transgressions among Kiowa equestrian foragers (North America); analyze a sample of 302 transgressions among Mentawai horticulturalists (Indonesia); and review retributive procedures documented among Nuer pastoralists (South Sudan). Consistent with the relation-restoration hypothesis, we find that third-party punishment is rare; that most third-party involvement aims at resolving conflicts; that costs paid by offenders serve to achieve forgiveness by repairing victims; that punitive justice is accompanied by ceremonial procedures aimed at limiting conflict and restoring goodwill; and that failures to impose costs contribute to a decline in reciprocal cooperation. Although we document rare instances of third-party punishment among the Kiowa (6.6% of offenses), punitive justice more often serves as restorative justice, appeasing victims' urge for revenge while not overly harming offenders' interests to ensure reconciliation. [ABSTRACT FROM AUTHOR]