Related Experiment Video
Updated: Jul 7, 2026

Exploring X Chromosomal Aberrations in Ovarian Cells by Using Fluorescence In Situ Hybridization
Published on: April 7, 2023
An association between the kinship and fertility of human couples
Agnar Helgason1, Saebjörn Pálsson, Daníel F Gudbjartsson
1deCODE Genetics, Sturlugata 8, 101 Reykjavik, Iceland. agnar@decode.is
Abstract:
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.
Related Concept Videos
Fertilization
Inclusive Fitness
Natural Selection and Mating Preferences
Females, due to their biological roles in conception, pregnancy, and nursing, inherently...
Close Relationships and Culture
Relationship Growth
Nondisjunction

