A study of white married U.S. couples — mostly born in the 1930s — concluded that spouses are more genetically similar to each other than they are to random individuals.
In a paper published in the journal PNAS, scientists investigated the statistical likelihood that people will marry someone with a similar genotype.
"It is well established that individuals are more similar to their spouses than other individuals on important traits, such as education level," wrote lead author Benjamin Domingue, a behavioral science researcher at the University of Colorado, Boulder, and his colleagues. "The genetic similarity, or lack thereof, between spouses is less well understood."
Study authors based their conclusion on data from 9,429 non-Hispanic white individuals in the ongoing Health and Retirement Study, which is sponsored by the National Institute on Aging. The sample included 825 spousal pairs who were all born between 1920 and 1970. However, the scientists said more research is needed. They wrote, "The results represented here only represent a first step in understanding the ways in which humans may assortively mate with respect to their genome."
Los Angeles Times