Saying 'I Do' Because of Similar DNA?
People also tend to marry those similar to themselves in terms of race, ethnicity and even body size and shape. Genes may also shape even more subtle biological distinctions that draw people together in ways we don't yet understand, Domingue added.
At least one expert is skeptical of the researchers' conclusions. Since these life circumstances play a large role in determining lifelong partners, it may be misleading to say people choose spouses based on genetic similarity, said Neil Risch, director of the Center for Human Genetics at the University of California, San Francisco.
"This [study] seems to suggest that mate choice is based on genes. The genes are, in a sense, a bystander," said Risch, who is also president-elect of the American Society of Human Genetics. "Historically, in a highly ethnically and geographically structured population, say Chicago, it might have been the case that Eastern Europeans only married other Eastern Europeans, Southern Europeans only married Southern Europeans, and Northern Europeans only married Northern Europeans," he continued.
"This would lead to significant correlations for genetic factors differentiating these ethnic groups, but has nothing to do with any traits or characteristics which underlie mate choice," he said. "It may be simply more an issue of local geography."
Dennis Thompson