Oxytocin Made You Do It? Lying Is Hormonal, Scientists Say

Subjects were as honest as one might expect regarding their own good when dosed with 'bonding hormone’ but they’d be more likely to fib for you, Ben-Gurion University team finds.

Ruth Schuster
Ruth Schuster
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The bond between a mother and her child can also be put down to hormones, say the researchers.Credit: AP
Ruth Schuster
Ruth Schuster

What makes people lie? Everyone does it, with all due respect to George Washington and his cherry tree. They will lie for themselves and they will also lie on behalf of a group they hold dear without batting an eyelash. Now it turns out that it isn’t just a question of morality or upbringing: The tendency to lie for the group is regulated by hormones, Israeli scientists say.

Specifically, lying for the group involves the hormone oxytocin, claim psychologists Dr. Shaul Shalvi of Ben-Gurion University of the Negev and Carsten K. W. De Dreu of the University of Amsterdam, in a study published Monday in Proceedings of the National Academy of Sciences.

Their test was carried out as stringently as a pharma company testing a new drug. Test subjects given oxytocin in spray form up their noses tended to lie to benefit their groups more than did their peers receiving a placebo.

Note that the oxytocin-dosed test subjects had no increased tendency to lie for their own benefit. Their findings support a “functional” approach to morality, say the scientists.

What does oxytocin do? Briefly, gives you a rush of bonhomie. Biologically, it wears two hats, though in both it has regulatory functions. It is a hormone – a regulatory molecule that causes bodily reactions. And it is also a neurotransmitter, meaning it facilitates communication between nerve cells.

Oxytocin has been associated with bonding, such as in maternal behavior. During labor, the mother’s blood stream becomes flooded with the stuff – it also induces labor and lactation. Tests have indicated that in its absence, monkey mothers don’t bond with their babies. It improves social interaction and is famously released during orgasm, when bonding and bonhomie are a good thing.

Oxytocin has also been correlated with trust and empathy, reduced social anxiety and relatively pro-social choices in anonymous games. At the other end of the rainbow, however, oxytocin also stimulates defense-related aggression. But the group-serving dishonesty would fall into the category of a bonding agent.

This miracle molecule is a short protein chain produced in the hypothalamus with just nine amino acids. For comparison, human hemoglobin has 474 amino acid molecules in four chains.

I lie because I live

To test oxytocin’s effect on lies that serve one’s own group, Shalvi and De Dreu created three teams of 30 men each. Each was dosed with oxytocin or placebo, in a spray up the nose. It can’t be delivered in oral form because it gets digested. And previous studies have shown that oxytocin administered nasally reaches the brain.

The dosed participants had to predict the outcomes of 10 coin tosses – and keep their guesses to themselves. The process was predict, shut up, toss the coin, see the outcome – head or tails, and report whether their prediction was correct.

But only the participants knew whether they’d guessed right, and they had the option of lying about it to earn more money. How? Get it right, and you get 30 eurocents to be split between themselves and their two group members who were engaging in the same task.

The ultimate individual outcome was the team’s outcome divided by three. The results were gauged by statistics.

Clearly, there was some fibbing gone on. “The statistical probability of someone correctly guessing the results of 9 or 10 coin tosses is about 1%. Yet, 53% of those who were given oxytocin claimed to have predicted that many coin tosses,” Shalvi says. “That such a pattern occurred by chance is extremely unlikely.” That is true.

Among the participants who got placebo, 23% reported correctly predicting 9 or 10 times, also reflecting a high likelihood they were telling tall tales. But the ones who got oxycontin lied more.

Being helpful gives you a rush

Another test was performed to make sure the oxycontin boosted lying for the group, but not oneself: The individual outcome was based solely on the individual and not on the team’s result divided by three. The two scientists found no statistically significant difference between subjects dosed with hormone and those who got placebo.

In other words, it seems the social-empathy hormone leads to lying for the group, but not for oneself. Does this touch on morality?  

“Our results suggest people are willing to bend ethical rules to help the people close to us, like our team or family,” says Shalvi, “This raises an interesting, although perhaps more philosophical question: Are all lies immoral?”

The answer to that one isn’t likely to lie in biochemical studies done on hormones. But do note that last year, scientists reported that oxytocin, truly a remarkable biochemical, apparently improved functioning in schizophrenics – because it helped them notice when other people were lying to them, claimed a team led by Joshua D. Woolley of the University of California.

The research received funding from the People Program (Marie Curie Actions) of the European Union’s Seventh Framework Program and by the Netherlands Science Foundation.

Psychologist Dr. Shaul Shalvi of Ben-Gurion University of the Negev, who together with Carsten K. W. De Dreu of the University of Amsterdam, researched the effects of the hormone oxytocin.Credit: Ben-Gurion University of the Negev