WASHINGTON: The chance that infidelity will intrude on a romantic relationship may be written in the couple’s genes, a study has found. The results suggest a DNA test could tell a man the rough chances his female partner will cheat on him, though it wouldn’t necessarily work the opposite way. Researchers focused on a set of genes that past studies have implicated in a link between sexual attraction and genetic similarity. The cluster of genes is termed the major histocompatibility complex, or MHC.
The researchers studied 48 male-female couples who were either dating “exclusively” or married or living together. As the proportion of MHC genes the couple shared increased, “women’s sexual responsivity to their partners decreased, their number of outside] sexual partners increased, and their attraction to men other than their primary partners increased,” the researchers wrote in a paper describing their findings.
Two quantities were almost equal on average, according to Christine Garver-Apgar, the study’ author: the fraction of MHC genes shared, and the woman’s number of extra partners. In other words, if the man and woman had half the genes in common, the woman would have on average nearly half a lover on the side. But these tendencies were found only for women; men’s attraction and likelihood of cheating appeared unrelated to the genes, they wrote.
This may also explain past studies suggesting that humans and animals prefer mates with dissimilar MHC genes, according to scientists. Such a preference might help assure that offspring have a wide range of immunity genes in the holster, giving them an edge over pathogens.
Infidelity touches about half of all couples, married or not, according to infidelity researcher Shirley Glass. Last year, scientists also found one in 25 dads may be raising another man’s child.
Source :The Times Of India
