The scientists found in their study, published in the journal " Proceedings " of the American Academy of Sciences, that men with high amounts of oxytocin in the brain see their more attractive than those with lower levels couples.
To achieve these results provided oxytocin by nasal spray to a group of forty heterosexual men living with their partner at the time of the study.
They found that , at the sight of the couple themselves , this hormone will activate occupies the center of gratification in the male brain , thereby strengthening monogamous behavior in males.
"This biological mechanism acts very much like a drug," since " both love and drug seeks to encourage the fulfillment center of the brain ," says study leader René Hurlemann .
As noted by scientist , oxytocin stimulates contact between couples because, through it , the level of this hormone remains high and this is reflected in a strengthening of the relationship.
Hurlemann recalls that "man is an exception " because monogamy is not a widespread pattern of behavior among wild animals.
