The Monogamy Drug

Looking for a warm and cuddly holiday season? Try a little oxytocin spritz along with the turkey.

Oxytocin is a hormone produced by the pituitary gland that activates certain reward receptors in the brain. It makes people compassionate. It makes women love their babies. It’s released during orgasm and causes couples to feel close to one another, thus its nickname, “the cuddle drug.” It’s also involved in addictive behavior, along with dopamine, another “feel-good” neurotransmitter.

A couple of recent experiments by Dr. Rene Hurlemann at the Bonn University Medical Center, however, suggest that oxytocin is a hormone that keeps men monogamous. Contrary to all kinds of evolutionary thinking, which would suggest that men would be driven to spread their seed in all directions, oxytocin appears to increase a man’s attachment to his sexual partner.

Monogamy is rare in the mammalian world. Only 3 to 5 percent of warm-blooded creatures pair up for life.

In his first experiment, Dr. Hurlemann spritzed a few men with oxytocin and then introduced them to an attractive woman. The men in monogamous relationships stayed 6.5 inches farther away, on average, from the woman than single men did. When the same partnered men weren’t spritzed, the extra distance disappeared.

Dr. Hurlemann decided to investigate further.

In his second experiment, the male subjects, who were all in permanent relationships, were hooked up to a brain scan. First, they were spritzed with oxytocin, and then they were shown photos of their partner, of other attractive women, and of female acquaintances.

Sure enough. The parts of the brain associated with reward (the nucleus accumbens) and motivation (ventral tegmental area) lit up at photos of the partner, but not at the strangers or at female acquaintances. Under the amorous effect of oxytocin, these guys also felt that their partners were more attractive than photos of the other women.

The researchers hypothesize that this hormone that is released during close physical contact and that tickles our pleasure center reinforces monogamy this way: A man may limit the spread of his genes by sticking with one partner, evolutionarily speaking. But by sticking around to create a stable environment and helping to rear his offspring, he increases the likelihood that they will survive to reproduce. So, rather than feckless promiscuity, evolution takes a different tack and oxytocin is the carrot.

And while that’s a cold, scientific view of the situation, lots of touching, cuddling, massaging, and good old sex will keep your man’s pleasure centers (as well as your own) well-lubed and attached to the source of the goodies! In Dr. Hurlemann’s research, even the close presence of the partner was enough to release oxytocin, giving new meaning to the saying, “stand by your man.”

While you’re basting that turkey, keep in mind that our traditional holiday fowl is also high in dopamine, which might be well-poised to edge out Valentine’s Day (even in spite of the afternoon football) as the season of love.