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 was also correlated with the longevity of a relationship. Couples with the highest levels were the ones still together six months later. They were also more attuned to each other than the low-oxytocin couples when Feldman asked them to talk about a shared positive experience. The high-oxytocin couples finished each other’s sentences, laughed together and touched each other more often. Feldman says it’s still not clear whether oxytocin was responsible for the stability of the couple’s bond six months later or if couples who weren’t as connected failed to trigger the oxytocin system.
One way to clarify that question is to give individuals oxytocin rather than just measure naturally occurring levels. In experiments by couple therapist and researcher Beate Ditzen at the University of Zurich, couples each sprayed a liquid containing oxytocin up their noses (which ensures that the hormone reaches the brain). Ditzen then got them to talk with each other about an issue that both partners said often lead to disagreement or fighting, such as who did the housework or how they spent their free time. She observed how they communicated with each other during the discussion compared with couples who didn’t get the hormone.
The first time Ditzen and her colleagues did this experiment they found that for both men and women oxytocin improved communication and lowered cortisol, a stress hormone. But in a recent study published in Social Cognitive and Affective Neuroscience, Ditzen and her colleagues measured salivary alpha-amylase (sAA)—an enzyme tied specifically to social stress—and found that men and women responded differently. Women who got oxytocin showed a decrease in sAA whereas men showed an increase and reported feeling more intense emotions. Counterintuitively, these men were also better at communication during conflict: they smiled more, had more eye-contact and were more open about their feelings. These behaviors are essential for peaceful conflict resolution.
Research shows that men tend to withdraw during conflict with their mate, which leads to a breakdown in communication and relationship dissatisfaction on both sides. Ditzen thinks the higher emotional arousal that oxytocin-infused men experience in her experiment may result in more engagement with their partner and thus more communication.
Although the new results provide evidence that oxytocin influences the way couples interact, Ditzen warns that it doesn’t tell us whether oxytocin is directly causing these behaviors.