Science 8 February 2008:
Vol. 319. no. 5864, pp. 813 - 816
DOI: 10.1126/science.1150232
Reports
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
Previous studies have reported that related human couples tend to produce more children than unrelated couples but have been unable to determine whether this difference is biological or stems from socioeconomic variables. Our results, drawn from all known couples of the Icelandic population born between 1800 and 1965, show a significant positive association between kinship and fertility, with the greatest reproductive success observed for couples related at the level of third and fourth cousins. Owing to the relative socioeconomic homogeneity of Icelanders, and the observation of highly significant differences in the fertility of couples separated by very fine intervals of kinship, we conclude that this association is likely to have a biological basis.
1 deCODE Genetics, Sturlugata 8, 101 Reykjavik, Iceland.
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. |
