A new study conducted by German researchers suggests that hormone oxytocin plays a key role in encouraging monogamy and makes men find their partners more attractive.
The study was conducted by researchers at University of Bonn who said that a whiff of the hormone, released when couples kiss or hug had no effect on making strangers or work colleagues look more beautiful to men. Oxytocin hormone is also released during childbirth which helps mothers bond with their babies.
The researchers selected around 40 young men who said that they were passionately in love with their partners. They were randomly given a placebo or a boost of oxytocin hormone and were shown pictures of their partners, work colleagues and strangers and were asked to rate how attractive they found the women.
"When the men received the oxytocin instead of placebo, the reward system in the brain was very active when viewing their partner and they perceived them as more attractive than other women. The activation of the reward system with the aid of oxytocin had a very selective effect with the pictures of the partners. We did not detect this effect with pictures of long-standing acquaintances", lead author Dirk Scheele said.
The study has been published in the Proceedings of the National Academy of Sciences.