We argue that ritual is not a by-product as Boyer & Lienard (B&L) claim, but rather an evolved adaptation for social communication that facilitates non-agonistic social interactions among non-kin. We review the neurophysiological effects of ritual and propose neural structures and networks beyond the cortical-striato-pallidal-thalamic circuit (CSPT) likely to be implicated in ritual. The adaptationist approach to ritual offers a more parsimonious model for understanding these effects as well as the findings B&L present. (Published Online February 8 2007).

Henrich et al.'s findings are generally consistent with the findings of other experimental field studies. However, the methodological variations deployed across field sites produced several systematic biases in their results. Hence, although the project is destined to become a watershed study, their results should be interpreted prudently.