It was also notable that the oxytocin spray had no effect on the distance that single men chose to keep between themselves and the attractive woman. This shows that oxytocin clearly has a measurable effect on men in relationships. It suggests that the hormone promotes fidelity in humans. This is in keeping with previous research that was conducted using animals in a lab, which suggested the hormone played a role in pair-bonding.
In humans, oxytocin has been found to promote the bond between parents and children, increase levels of trust, and even to help reduce conflict between couples. Another study, earlier in the year, found that couples with high levels of oxytocin in the early stages of their relationship were more likely to stay together six months later than couples with lower levels of the hormone.
However, this is the first study to suggest that oxytocin could contribute to the maintenance of a relationship. The study involved 57 heterosexual men, around half of whom were in relationships. After receiving either a dose of oxytocin or taking a placebo, the participants were introduced to a female experimenter who described as “attractive”.
They were then asked to state the ideal distance that the woman should stand away from them highlighting when standing too close felt uncomfortable.