Oxytocin may strengthen monogamy in men
Oxytocin, known as the "love hormone" for its role in social bonding, activates the reward center in a man's brain, and that, say scientists, may actually promote male monogamy.
Though humans practice monogamy frequently, most mammals do not, so scientists from Germany and China decided to look for a biological explanation behind fidelity in loving human relationships.
For the study, the researchers showed 40 heterosexual men in permanent relationships pictures of their female partner. They also showed them pictures of other women. During this time, a dose of oxytocin was given to the participants via a nasal spray, and later a placebo was provided. The scientists also looked at the participants’ brain activity with functional magnetic resonance tomography.
They found that when the men received oxytocin instead of placebo, the reward center in their brains became very active when viewing their partners, and they saw them as more attractive than other women.
The researchers say that the oxytocin strengthens the partner bond, which in turn increases the stability of the people providing nutrition. And that aids in the survival of children. This provides a biological incentive for both men and women to stay together because the genes of both live on in their children.
In another test, the researchers wanted to see if oxytocin would have the same effect when men viewed women they knew, but who were not their partners. But the oxytocin did not have the same effect.
Researchers also found that when people break up, they fall into depression because they are being deprived of oxytocin. But they do not think that a treatment with oxytocin would be helpful, because it would only increase longing for the partner.