This new research is consistent with the concept that bonding behaviors strengthen human pair bonds.
New research links levels of the “cuddle hormone” with falling, and staying, in love.
There’s nothing like the bliss of a new romance. And yet, many experiencing such rapture find it disrupted by a nagging question: How do we know our love will last? Newly published research suggests a possible answer: Get your oxytocin levels checked. A team of researchers led by Inna Schneiderman of the Gonda Brain Sciences Center of Israel’s Bar-Ilan University have just published a study examining the role oxytocin, commonly called the “cuddle hormone,” plays in the early stages of romantic relationships. While differentiating cause and effect is tricky, the researchers find a strong link between lasting relationships and high levels of the hormone.
Oxytocin, as they note in the journal Psychoneuroendocrinology, promotes trust, bonding and attachment — between adults, and between parents and their offspring. (Less appealingly, it can also promote ethnocentrism.) Schneiderman’s study featured 163 people in their early to mid-20s, 120 of whom had recently initiated a love affair. (On average, their relationship had begun 2.5 months prior to testing.) All had their blood tested for oxytocin levels.
“New lovers had substantially higher plasma levels of oxytocin, as compared to non-attached singles,” the researchers report. “These findings are consistent with those reported for other mammals, particularly monogamous rodent species in which oxytocin has shown to play a critical role in the formation of pair bonds.”
Since they didn’t measure oxytocin levels before the relationships began, Schneiderman and her colleagues can’t say for certain whether they increased during the romantic bonding process, or whether “individuals with high levels of oxytocin are more likely to fall in love.”
Six months later, the researchers located 54 of the 60 couples and retested the 36 who were still together. Their oxytocin levels were still at the same high level, which either explains or reflects the fact they were still happily bonded.
Perhaps the most striking finding: “Couples who stayed together showed higher oxytocin levels at the initial period of romantic attachment” than those who broke up. “These findings suggest that oxytocin in the first months of romantic love may serve as an index of relationship duration,” the researchers write.
This brings to mind the intriguing possibility of oxytocin-enhanced relationship repair — couples counseling augmented by hormone injections. In previous studies, raising people’s oxytocin level (via nasal spray) “was found to increase bonding-related behavior, including … trust and empathy,” the researchers note.
That said, the study raises a chicken-and-egg question, since it isn’t clear whether high oxytocin levels lead to more closeness or whether romantic behavior increases oxytocin levels.
During their initial testing, the lovers were interviewed about their relationship and observed while talking together. The researchers found a correlation between oxytocin levels and their level of “interactive reciprocity” — which is to say, their responsiveness to one another and tendency to engage in affectionate touching.
“Oxytocin is known to function as a bio-behavioral feedback loop,” the researchers note, adding that “research in mammals showed that more touch and contact increased oxytocin receptor density.” This suggests loving couples may get into a positive routine in which “higher levels of reciprocity and touch” allow them to maintain elevated oxytocin levels, sustaining their feeling of emotional connection.
So couples may not need artificial administrations of the cuddle hormone; they may just need to cuddle.
Oxytocin during the initial stages of romantic attachment: Relations to couples’ interactive reciprocity
- Inna Schneidermana, Orna Zagoory-Sharona, James F. Leckmanb, Ruth Feldmana, b,
- a Department of Psychology and the Gonda Brain Sciences Center, Bar-Ilan University, Ramat-Gan, Israel
- b Child Study Center, Yale University, New Haven, CT, USA
- Received 3 October 2011. Revised 29 December 2011. Accepted 29 December 2011. Available online 25 January 2012.
Romantic relationships can have a profound effect on adults’ health and well-being whereas the inability to maintain intimate bonds has been associated with physical and emotional distress. Studies in monogamous mammalian species underscore the central role of oxytocin (OT) in pair-bonding and human imaging studies implicate OT-rich brain areas in early romantic love. To assess the role of OT in romantic attachment, we examined plasma OT in 163 young adults: 120 new lovers (60 couples) three months after the initiation of their romantic relationship and 43 non-attached singles. Twenty-five of the 36 couples who stayed together were seen again six months later. Couples were observed in dyadic interactions and were each interviewed regarding relationship-related thoughts and behaviors. OT was significantly higher in new lovers compared to singles, F(1, 152) = 109.33, p < .001, which may suggest increased activity of the oxytocinergic system during the early stages of romantic attachment. These high levels of OT among new lovers did not decrease six months later and showed high individual stability. OT correlated with the couples’ interactive reciprocity, including social focus, positive affect, affectionate touch, and synchronized dyadic states, and with anxieties and worries regarding the partner and the relationship, findings which parallel those described for parent–infant bonding. OT levels at the first assessment differentiated couples who stayed together six months later from those who separated during this period. Regression analysis showed that OT predicted interactive reciprocity independent of sex, relationship duration, and the partner's OT. Findings suggest that OT may play an important role at the first stages of romantic attachment and lend support to evolutionary models suggesting that parental and romantic attachment share underlying bio-behavioral mechanisms.