Response to Comments on "An Association Between the Kinship and Fertility of Human Couples"

Abstract

Analyses of 137,844 Icelandic couples born between 1800 and 1965 reveal a monotonic drop in fertility with increasing marital radius (distance between the birthplaces of spouses). Marital radius was moderately correlated with kinship between spouses. This correlation was strongest during the peak of urbanization (1875 to 1925) but very weak after 1950. These results raise doubts about the use of marital radius as a proxy for kinship in contemporary human populations.