Response to Comments on "An Association Between the Kinship and Fertility of Human Couples"
Agnar Helgason,1,2*
Snæbjörn Pálsson,1,3
Daníel F. Guðbjartsson,1
Þórður Kristjánsson,1
Kári Stefánsson1,4
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.
2 Department of Anthropology, University of Iceland, 101 Reykjavik, Iceland
3 Department of Biology, University of Iceland, 101 Reykjavik, Iceland
4 Faculty of Medicine, University of Iceland, 101 Reykjavik, Iceland.
* To whom correspondence should be addressed. E-mail: agnar{at}decode.is
