“Kissing Cousins”

A fundamental unresolved question in demographic research is the relative importance of biological versus social factors in determining infant and child mortality. One important biogenetic factor is consanguinity (marriage between close biological relatives), which causes the expression of deleterious recessive genes. Study of the impact of first‐cousin marriage on infant and child mortality among reproductively isolated Bedouin agropastoralists of the Bekaa Valley, Lebanon, shows that, after controlling for socioeconomic and demographic factors, consanguineous first‐cousin marriages negatively impact infant survival but not child survival. Exploration of the multiple causes of consanguinity is required for a more integrated perspective on marriage between relatives.