(Time) How Oxytocin Makes Men (Almost) Monogamous
The hormone and brain chemical best known for its role in love — it’s also responsible for helping infants bond to their mothers — can also make romantic partners look more attractive than strangers to men, even if both are objectively equally good looking.
Published in the Proceedings of the National Academy of Sciences, the study included 40 young men, all of whom had been in a relationship for at least six months and reported being passionately in love with their partners. While in a brain scanner, they either inhaled oxytocin or placebo via nasal spray while they viewed pictures of either their partners, women they knew but were not dating or women they had never met. The pictures were matched so that comparison women had been rated by independent observers as being equally attractive as the partners. In the men who were given oxytocin, the pleasure and desire regions of their brains lit up when they saw pictures of the women they loved — but not when they looked at strangers. Some of these regions were also activated by the images of the women the men knew, but not as strongly as by the pictures of their loved ones, suggesting that it made their partners more desirable.