Sex, hugs, cuddling, hand-holding, and even innocent little kisses before you dash out the door to work every morning — all of them pay dividends toward a long and loving relationship. And now we have the science to back it up.
According to a new study, the culprit is our old friend oxytocin, a.k.a. the “love hormone.” Its levels shoot up whenever we make physical contact with someone important to us.
It’s widely understood that its reward system plays a crucial role in deepening the bond between two lovers. Past studies have suggested that it may help keep men from cheating, while others point to its dark side, which can make an abrupt breakup feel physiologically devastating.
Humans and many mammals are monogamous creatures (at least most of the time). What makes us go out of our way to lock ourselves into a committed relationship is still largely a mystery, suggesting there’s some sort of biological advantage. “Monogamy is actually quite costly for humans, so there must be some form of benefit,” said Rene Hurlemann, a psychiatrist at the University of Bonn in Germany who led the most recent study. “We’d expect humans, especially males, would disseminate their genes.”
So what’s inspiring warm-blooded males to stay loyal?
Researchers, publishing their findings in the Proceedings of the National Academy of Sciences, discovered that regular jolts of oxytocin make our partners more attractive, to us and only us.

Hurlemann and his colleagues took 20 men who were in long-term and passionate romantic relationships with women, hooked them up to functional magnetic resonance imaging scanners, and showed them photos of their loved ones interspersed with images of an unfamiliar but equally comely stranger, or a house. Some men were spritzed with oxytocin, others with a placebo. To test whether oxytocin varied only with familiarity, they substituted highly familiar faces for the house images. Afterward, the men filled out the Passionate Love Scale questionnaire, which showed that their inner Romeo prevailed over their inner Lothario. They were fixated on their current romantic partner. [Los Angeles Times]

Makes sense. A “steady diet” of oxytocin helps trigger the release of dopamine, which means we’re almost literally addicted to the person we’re in love with. Cuddling is a drug, so to speak.
Such findings give us a better understanding of how some couples manage to make it for the long haul, and explains why physical support is tied so intrinsically with our emotional health. Take our friends John and Ann Betar, who eloped on Nov. 25, 1932, and, in addition to being completely adorable and amazing, are still madly in love with one another. What’s their secret after 81 years of marriage?
“We always hold hands,” said John.