This article tests four hypotheses regarding scarification, which is described as 1) a rite of passage, 2) a hardening/trauma procedure, 3) a nonadaptive sexually selected character, or 4) an adaptive pathogen driven sexually selected character. Only the third hypothesis is supported in a worldwide sample, suggesting that scarification is associated with polygyny. The other three are each supported in different regional subsamples—principally the first hypothesis (supported in Africa, the Insular Pacific, and South America).