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No, the "love hormone" oxytocin won't stop your spouse from cheating

Oxytocin at work.
Oxytocin at work.
(Gemma Bou)

There are few chemicals in your body that get more attention these days than oxytocin.

Nicknamed the "love hormone," it's been credited with keeping married men from cheating and hailed as a potential cure for autism. Many of these purported benefits turn out to be total myths — but that hasn't stopped people from buying the chemical (which is widely available as a nasal spray) and trying to improve their love lives.

So what's the truth about oxytocin? It does affect our brains and behavior in complex ways, and scientists are still figuring out if there are any useful clinical uses. But many of the claims being made about it are overblown. Here's a rundown of what we know so far.

What is oxytocin?


The oxytocin molecule. (MindZiper/Wikimedia commons)

Oxytocin is a hormone that's naturally produced inside your brain and is released in response to physical contact and sex, among other activities. It seems to be particularly important in the formation of romantic relationships and social connections, making us feel closer to others.

"It affects your emotions more than your thoughts — not your conscious thinking, but how you feel," says C. Sue Carter, the biologist who initially linked the hormone with social behavior.

Although we've known about oxytocin for a while, research into how exactly it affects our emotions has exploded in the last decade. But some of this research — often in the early stages — has given rise to wild claims and myths.


(Ed Yourdon)

Myth #1: Oxytocin stops men from cheating on their wives

In early research, scientists found that prairie voles — a species celebrated for its monogamy — get a surge of oxytocin in their brains when they have sex for the first time. That chemical is necessary for the voles to forge their lifelong bond.

This discovery prompted research in humans, who also receive a rush of oxytocin after sex or physical contact. Some research found that the brains of monogamous men are more sensitive to oxytocin than the brains of perpetually single men. Another much-discussed study even found that when oxytocin was given to men in a committed relationship, they kept a slightly greater distance away from a female deemed to be attractive.

This discovery led the media to hail oxytocin as the "love hormone," responsible for keeping men faithful. Dr. Phil, for one, advised women to raise their partners' oxytocin levels by touching and hugging them more, in order to "lower the risk" of cheating. Eric Keroack, a supporter of abstinence-only sex education, controversially argued that premarital sex damaged the human brain's ability to produce oxytocin, thereby ruining someone's chance of a healthy monogamous relationship.

Truth: Oxytocin is no guarantee of faithfulness

Even in prairie voles, it turns out, oxytocin doesn't actually prevent cheating. More recent research has revealed that while the rodents do form lifelong pair bonds, these relationships don't actually preclude occasional sex with other voles.

In humans, too, the full picture is more complicated. Oxytocin is deeply involved in sexual interactions and bonds between people, but there isn't strong evidence tying it to monogamy.

Sure, touching one's partner causes a spike in oxytocin, but so does getting a massage from a stranger. Compared to habitually single men, monogamous men do have brains that are more sensitive to oxytocin, but the difference is negligible. "The media like to describe this as a way of predicting who's going to cheat," says Idan Shalev, a biologist who has researched oxytocin. "But the correlation is really, really limited."

Moreover, the effect of oxytocin appears to be dependent on another hormone that's widely overlooked: vasopressin. In prairie voles, both hormones need to be present for a long-term bond between mates to form, and early research suggests it's critical in regulating human social interactions as well.



Myth #2: Oxytocin makes you more social

Scientists have also made a number of findings about the ability to oxytocin to help connect people in general. But these, too, tend to get misinterpreted.

Give someone a dose of oxytocin, and they'll maintain more eye contact with others, be able to more accurately interpret others' emotions, and become more trusting. "In general, when we've given oxytocin to subjects, we've seen that they're more attuned to other people and social stimuli," says Shalev.

But people have run wild with these findings. There are reports of parties where strangers take oxytocin together as an icebreaker. Some people reportedly take oxytocin before dates to increase their chances of feeling a connection. Nasal oxytocin spray has been marketed as Liquid Trusta product you can spray in a room to "create a trustworthy vibe."

Truth: Oxytocin can help and hurt social interactions

For starters, just spraying oxytocin into a room won't have any effect at all. "This is completely bullshit," Shalev says. "You can't just spray it — you need to directly inhale it to get it into the brain."

But more importantly, oxytocin doesn't always promote positive feelings and connections with others. As with sex, it's involved in social interactions, but in a more complex way.

"It seems to makes you more attuned to emotions in general — not only positive emotions, but also negative ones," Shalev adds. "If you experience trauma and are given oxytocin, for instance, that can actually worsen your situation."

In experiments, oxytocin has been shown to increase the level of trust people put in strangers, but if those strangers betray them, the subjects actually become less trusting than if they'd never been given the hormone. In certain situations, it's also been found to make people more envious and distrustful of people who have different ethnic backgrounds than themselves.


(Andrew Magill)

Myth #3: Oxytocin is an autism cure

The defining aspect of autism is a difficulty connecting with others, so a hormone that might help someone make those connections is an intriguing potential cure.

Several studies are underway on this question, and one of first to be published found that giving a single dose of oxytocin to children with autism stimulated areas in their brains that are known to be involved in responding to social cues.

Due to the buzz surrounding oxytocin, there are now reports of doctors prescribing it to children with autism — even though it hasn't been approved for this use.

Truth: We still don't know how oxytocin affects autism

Many parents of children with autism are understandably excited about the potential of oxytocin — but that doesn't mean they should be administering it on their own. "The results are promising, but they're very preliminary," Shalev says.

There are several obstacles currently standing in the way of oxytocin being a cure. The dose commonly used in experiments only lasts about two hours, and scientists still haven't verified the safety of larger, longer-lasting doses. Scientists also haven't evaluated the potential dangers of using it long-term: it's possible, Shalev says, that routine use could lead to the brain becoming tolerant to oxytocin over time, or reducing its own production of it.

But most importantly, the studies conducted so far haven't actually found that oxytocin reduces any behavioral symptoms of autism — just that it can increase activity in certain parts of the brain. "Many parents are justifiably desperate for something," C. Sue Carter says, "but we're still in the very early stages of understanding how this works, and there's a desperate need for real science, not parents sorting it out for themselves."

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