How do cultural variations emerge from universal mechanisms?

Diverse cultural norms governing economic behavior might emerge from a dynamic interaction of universal but flexible predispositions that get calibrated to biologically meaningful features of the local social and physical ecology. This impressive cross-cultural effort could better elucidate such gene-culture interactions by incorporating theory-driven experimental manipulations (e.g., comparing kin and non-kin exchanges), as well as analyses of mediating cognitive processes.