Opposites attract to get healthier kids

VIENNA, May 25 (UPI) -- Genetic opposites do attract when choosing a mate because of the subconscious drive to have healthy children, researchers in Brazil say.

Maria da Graca Bicalho of the University of Parana in Brazil said her research showed that people with diverse major histocompatibility complexes -- a gene-dense region of the genome that plays a role in reproductive success -- were more likely to choose each other as mates than those whose MHCs were similar.

The scientists studied MHC data from 90 married couples, and compared them with 152 randomly generated control couples. They counted the number of MHC dissimilarities among those who were real couples, and compared them with those in the randomly generated "virtual couples."

"If MHC genes did not influence mate selection, we would have expected to see similar results from both sets of couples," Bicalho said in a statement. "But we found that the real partners had significantly more MHC dissimilarities than we could have expected to find simply by chance."

The findings are being presented at the annual conference of the European Society of Human Genetics in Vienna.