Ancestral Guilt Attribution and Third-Party Punishment in Igbo Restorative Justice: A Behavioural Game Estimation of Indigenous Accountability Norms

Igbo restorative justice is commonly described as a system in which communal accountability and reintegration displace retributive punishment, yet the normative architecture that sustains this arrangement remains underspecified. The framework treats ancestral guilt as a transmitted moral liability that raises the perceived cost of norm violation for descendants, and models third-party punishment as a signalling device through which elders and age-grade institutions sustain accountability norms. A before-after-control-impact design is proposed to identify the causal effect of ancestral-guilt primes on punishment allocations, with operating characteristics characterised under a declared variance structure (between-cluster SD = 6.0, residual SD = 4.5, intraclass correlation = 0.64). Power was estimated across 2000 design cells; 54 clusters are required to detect a 5-percentage-point effect at 80% power. The framework yields testable propositions linking ancestral guilt attribution to punishment severity, third-party intervention and reintegration outcomes, and it clarifies the conditions under which Igbo restorative norms are likely to be sustained or eroded. The contribution is a formalisation of indigenous accountability norms that is compatible with experimental estimation and that treats ancestral guilt as a measurable construct rather than an ethnographic residual.