If cupid had studied neuroscience, he’d know to aim his arrows at the brain rather than the heart. Recent research suggests that for love to last, it’s best he dip those arrows in oxytocin. Although scientists have long known that this hormone is essential for monogamous rodents to stay true to their mates, and that it makes humans more trusting toward one another, they are now finding that it is also crucial to how we form and maintain romantic relationships.
A handful of new studies show that oxytocin makes us more sympathetic, supportive and open with our feelings—all necessary for couples to celebrate not just one Valentine’s Day, but many. These findings have led some researchers to investigate whether oxytocin can be used in couple therapy.
The first bit of evidence that points to oxytocin as nature’s love glue comes from researchers who measured the hormone in couples. Psychology professor Ruth Feldman at Bar-Ilan University in Israel, spent years studying oxytocin’s role in the mother–child bond and recently decided to dive into the uncharted waters of romantic bonds by comparing oxytocin levels in new lovers and singles. “The increase in oxytocin during the period of falling in love was the highest that we ever found,” she says of a study she and her colleagues published in Psychoneuroendocrinology. New lovers had double the amount Feldman usually sees in pregnant women.
Oxytocin is a hormone secreted by the posterior lobe of the pituitary gland, a pea-sized structure at the base of the brain.
It’s sometimes known as the “cuddle hormone” or the “love hormone,” because it is released when people snuggle up or bond socially. Even playing with your dog can cause an oxytocin surge, according to a 2009 study published in the journal Hormones and Behavior. But these monikers may be misleading.
Oxytocin can also intensify memories of bonding gone bad, such as in cases where men have poor relationships with their mothers. It can also make people less accepting of people they see as outsiders. In other words, whether oxytocin makes you feel cuddly or suspicious of others depends on the environment.
Oxytocin is a particularly important hormone for women. “Oxytocin is a peptide produced in the brain that was first recognized for its role in the birth process, and also in nursing,” said Larry Young, a behavioral neuroscientist at Emory University in Atlanta, Georgia.
The hormone causes uterine contractions during labor and helps shrink the uterus after delivery. When an infant suckles at his or her mother’s breast, the stimulation causes a release of oxytocin, which, in turn, orders the body to “let down” milk for the baby to drink.
Oxytocin also promotes mother-child bonding. Studies show that “female rats find pups to be aversive if [the females are] virgins,” Young told Live Science. “But once they give birth, the brain is transformed, so they find the pups irresistible,” he said. And similar findings are seen in humans.
A 2007 study published in the journal Psychological Science found that the higher a mom’s oxytocin levels in the first trimester of pregnancy, the more likely she was to engage in bonding behaviors such as singing to or bathing her baby.
Although maternal bonding may not always be hardwired — after all, human females can adopt babies and take care of them — oxytocin released during pregnancy “does seem to have a role in motivation and feelings of connectedness to a baby,” Young said. Studies also show that interacting with a baby causes the infant’s own oxytocin levels to increase, he added.
Oxytocin in men
In men, as in women, oxytocin facilitates bonding. Dads who got a boost of oxytocin via a nasal spray played more closely with their 5-month-old babies than dads who didn’t get the hormone zap, a 2012 study found. (There is another hormone, called vasopressin, which plays a stronger role in men.)
Another study found that men in relationships given a burst of oxytocin spray stood farther away from an attractive woman than men who weren’t given any oxytocin. Single men didn’t see any effect from the hormone, suggesting oxytocin may work as a fidelity booster for guys who are already bonded with another woman.
This anti-social effect of a social hormone brings some nuance to the story of oxytocin. In one study, researchers found that Dutch students given a snort of the hormone became more positive about fictional Dutch characters, but were more negative about characters with Arab or German names. The finding suggests that oxytocin’s social bonding effects are targeted at whomever a person perceives as part of their in-group, the researchers reported in January 2011 in the journal PNAS.
In another study, published in PNAS in 2010, men were given a dose of oxytocin and asked to write about their mothers. Those with secure relationships described their moms as more caring after the hormone dose. Those with troubled relationships actually saw their mothers as less caring. The hormone may help with the formation of social memories, according to the study researchers, so a whiff strengthens previous associations, whether good or bad.
“My view of what oxytocin is doing in the brain is making social information more salient,” Young said. “It connects brain areas involved in processing social information — whether it’s sights, faces, sounds or smells — and helps link those areas to the brain’s reward system.”
Dancing with your partner is one of the major ways to release this hormone. Head on off to the dance floor this Valentine’s Day to get those hormones released.