According to a new study, that cheatin’ heart is really more about the brain. And for better or for worse, some scientists say men are just born with it.

But no matter the vows, they say cheating is in the genes.

Dr. Brenda Wade is a psychology expert, who’s written three books on marriage and relationships.

She agrees with a study done in Sweden, in which scientists studied the gene types of 552 sets of twins.

They found a bonding chemical in some men, that makes them less likely to be married and more likely to have bad relationships.

However, disconcerting, the study also found that the brain can be trained to resist temptation.

Scientists say men don’t have to cheat, but they do have to work harder at staying faithful.

As for women, the scientists will put them under the monogamous microscope next.