We need behavioural ecology to explain the institutional authority of the gods

Atran & Norenzayan (A&N) rightly criticize cognitive theories for failure to explain sacrifice and commitment. But their attempt to reconcile cognitivism with commitment theory is unconvincing. Why should imaginary entities be effective in punishing moral defectors? Heavy costs are entailed in enforcing community-wide social contracts, and behavioural ecology is needed to explain how and why evolving humans could afford these costs.