Israeli and Dutch researchers have found that oxytocin, a brain hormone and neurotransmitter that boosts intimacy, promotes dishonesty and lying to benefit a group.
Psychologists Dr. Shaul Shalvi of Ben-Gurion University of the Negev in Beersheba and Dr. Carsten K. W. De Dreu of the University of Amsterdam published their findings Monday night in the Proceedings of the National Academy of Sciences.
They said their findings “reveal the underlying biological circuitries involved in group-serving dishonesty” and morality.
Oxytocin, known as the “bonding hormone” or “love hormone,” strengthens intimacy between lovers and between a mother and her baby during childbirth. It stimulates one’s social connection with a group, resulting in more empathy, less social anxiety, more pro-social choice in anonymous games and less of a fear response. Thus it also promotes defense-related aggression in a cohesive group, Shalvi and De Dreu wrote.
In a placebo-controlled, double- blind experiment on 60 healthy males, they divided participants into teams of three and gave them intranasal doses of oxytocin or placebos. They asked each man to privately predict the results of 10 coin-tosses, then toss a coin and report whether he was correct. Each correct prediction earned participants €0.30, split between the guesser and the two other members of his group. Since only participants knew if they predicted correctly, they could lie to earn money.
Shalvi said that the statistical probability of correctly guessing the results of nine or 10 coin tosses is around 1 percent. Of those who were given oxytocin, 53% claimed to have predicted that many coin tosses, compared to less than 25% of those who were given placebos.
The researchers then ran the experiment again with one change: The guesser kept the full €0.30 for a correct prediction, rather than sharing it. Here the researchers found no statistically significant difference between those who had been given oxytocin and those who had not. Thus, it seems oxytocin promotes lying for the benefit of one’s group, rather than for oneself.
“Our results suggest people are willing to bend ethical rules to help the people close to us, like our team or family,” concluded Shalvi, who heads BGU’s Center for Decision- Making and Economic Psychology. “This raises an interesting, although perhaps more philosophical, question: Are all lies immoral?”