Monday, November 26, 2012

Oxytocin nudges men to monogamy?

Scheele et al. show that oxytocin nasal spray causes married, but not single, men to keep a greater distance from attractive woman during a first encounter. They totally should do this experiment with gay married males!
In humans, interpersonal romantic attraction and the subsequent development of monogamous pair-bonds is substantially predicted by influential impressions formed during first encounters. The prosocial neuropeptide oxytocin (OXT) has been identified as a key facilitator of both interpersonal attraction and the formation of parental attachment. However, whether OXT contributes to the maintenance of monogamous bonds after they have been formed is unclear. In this randomized placebo-controlled trial, we provide the first behavioral evidence that the intranasal administration of OXT stimulates men in a monogamous relationship, but not single ones, to keep a much greater distance (∼10–15 cm) between themselves and an attractive woman during a first encounter. This avoidance of close personal proximity occurred in the physical presence of female but not male experimenters and was independent of gaze direction and whether the female experimenter or the subject was moving. We further confirmed this unexpected finding using a photograph-based approach/avoidance task that showed again that OXT only stimulated men in a monogamous relationship to approach pictures of attractive women more slowly. Importantly, these changes cannot be attributed to OXT altering the attitude of monogamous men toward attractive women or their judgments of and arousal by pictures of them. Together, our results suggest that where OXT release is stimulated during a monogamous relationship, it may additionally promote its maintenance by making men avoid signaling romantic interest to other women through close-approach behavior during social encounters. In this way, OXT may help to promote fidelity within monogamous human relationships.


  1. "They totally should do this experiment with gay married males!" - What do you think such an experiment would find, relative to this one? Personally, I suspect that gender preference does not correlate with monogamy / polygamy preference - so with gay married males, you'd see this same (or similar) proximity avoidance effect inverted by gender.

    Actually, my gut prediction is that the effect would be smaller, though still present, but I'd have to spend some time thinking about it to justify this prediction. Something about social expectations regarding same-gender groups as opposed to mixed-gender groups... Hmm.

    I also wonder if this could become a "treatment" for habitual cheaters - an anti-cheating nose spray! I think there might be ethical issues there but I'm not sure exactly how to articulate them. =P

    Oxytocin is shaping up to be a *very* interesting chemical. Thanks for posting this! =)

  2. I'm a gay married male, of 23 years, which is why I made the comment. I have seen data that suggest gay men in relationships are much less likely to be monogamous than straight men and lesbians (I can't put my hand on it right now). My suspicion is that oxytocin might have less effect in gay relationships.

  3. It was noted a few times that this was related to "first encounters" with attractive females. As I understand it, most cheating does not occur on a first encounter, but is more common to occur with people who have sort of connection beyond just raw sexual attraction (think secretaries, neighbors, even meeting online vs the hot girl at the bar). Does that make sense? I guess I am wondering if this is more of an effect on compulsive/judgement vs strengthening bonds. (as the single male is not considering "is this wrong").

  4. Why doesn't oxytocin keep monogamous women distanced unfamiliar men?
    Whatever happened to men spreading their seed? Based on Bateman's principle, it should be women that are wired for monogamy and men that are wired to seek women other than their partners. For more info, see