Sacred values as index signals of trustworthy character

<p>Sacred values are moral commitments held to be non-negotiable: their bearers refuse to trade them for material gain at any price. This rigidity is puzzling, because behavioral flexibility is a critical human adaptation. We argue that a sacred value enables cooperation by being a hard-to-fake signal of trustworthy character. In particular it indexes the ability to internalize moral rules in general. Observers extrapolate that a sacred valuer has internalized other moral rules, in particular rules against harming others, and hence regard them as trustworthy. Because that inference turns on individual character rather than group membership, the signal can operate across group lines. We test the account in six preregistered studies (N = 2,359), including an incentivized trust game with real stakes. Sacred value displays generate large trust effects that cross religious and ideological boundaries (Studies 1, 2); the trust is warranted, because sacred valuers behave more trustworthily when given the chance to exploit a partner (Study 3); and the evidence is consistent with our postulated two-stage mechanism: participants infer from single, idiosyncratic commitments that a sacred valuer has internalized rules across all five moral foundations; but the decision to trust is associated most strongly with the perception that harm-foundation rules have been internalized (Studies 4-6).</p>