Third cousins have more kids together

REYKJAVIK, Iceland, Feb. 8 (UPI) -- A study of people in Iceland found that couples who are third cousins have more children and grandchildren than other couples.

Researchers at the biopharmaceutical company deCODE genetics came to the conclusion after analyzing 200 years of comprehensive genealogical data on the population of Iceland. The report, published online in the journal Science, said there is likely a biological basis to explain the findings.

While the findings are somewhat counter intuitive from an evolutionary perspective, closer parental kinship can also decrease the likelihood of immunological incompatibility between mother and offspring, the company said Friday in a release..

DeCODE said the findings also suggest that the recent demographic in Iceland from a rural society to a highly urbanized one may serve to slow population growth, as people are exposed to a much broader range of distantly related potential mates.