Oxytocin Boosts Dishonesty

The so-called “love hormone” can make people more dishonest when it serves the interests of their group. 

By Ed Yong | March 31, 2014

OxytocinWIKIPEDIA, MINDZIPERThe hormone oxytocin is usually associated with positive traits like trust, cooperation, and empathy, but scientists have now found that it can make people more dishonest when their lies serve the interests of their group.

“This is the best evidence yet that oxytocin is not the ‘moral molecule,’” said Carsten de Dreu from the University of Amsterdam, who co-led the study, which was published today (March 31) in PNAS. “It doesn’t make people more moral or immoral. It shifts people’s focus from themselves to their group or tribe.”

These findings are “consistent with more and more research showing that the effects of oxytocin aren’t straightforward,” said Carolyn DeClerck from the University of Antwerp, who was not involved in the study. “They can be social or antisocial, depending on the situation and on individual differences.”

Decades of animal studies have shown that oxytocin is involved in social behavior, cementing the bond with monogamous voles and between ewes and lambs. Early human experiments linked the hormone to human behaviors like trust and emotional sensitivity, earning it nicknames such as “love hormone” or “cuddle chemical.”

But recent studies have shown that oxytocin has a dark side. Depending on the context, it can hinder trust, reduce cooperation, or trigger negative feelings like envy and schadenfreude. In 2011, de Dreu found that the hormone could make people biased toward others from their own ethnic or cultural group. 

His latest study, conducted by Shaul Shalvi from Ben-Gurion University of the Negev in Israel, adds to this subtler portrait of the hormone’s role. The duo ran a double-blind study in which 60 volunteers played a simple game, after inhaling either oxytocin or a placebo.

Working in teams of three, the recruits were asked to predict the toss of a virtual €1 coin and, once they saw the outcome, to say whether they had guessed correctly. A correct answer could gain them money, lose them money, or do nothing, and any winnings or losses would be divided evenly between the three anonymous teammates.

Shalvi and de Dreu found that when the volunteers stood to gain money, they cheated. On average, those who sniffed the placebo said that they had guessed correctly 67 percent of the time—more than expected by chance. Those who sniffed oxytocin were even more dishonest; they reported correct guesses 80 percent of the time, and were quicker to lie.

The duo found different results when they repeated their experiments, this time telling volunteers that their decisions would affect their own earnings, but not those of their teammates. This time, oxytocin had no effect on their lying.

These results showed that oxytocin could boost dishonest behavior, but only when it served the group and not the individual. “It can actually make people more immoral in the group situation because they’re deceiving, and stealing money from, the experimenter,” said de Dreu.

Even then, he and Shalvi found that the hormone’s effects varied depending on the situation. It had no apparent influence on the volunteers’ behavior when nothing was at stake, or when they stood to lose money. In the latter case, the oxytocin-sniffers under-reported their correct guesses just as often as did the volunteers that inhaled the placebo. De Dreu suggested that humans show such a strong aversion to loss that oxytocin has very little bearing on behavior in this context.

These results fit with the idea that oxytocin is a general social chemical that can wield opposing influences on human behavior in different contexts. “Some people may say that it’s still the ‘love hormone,’ because they love their in-group, but these people are in a very minimalistic setting and they don’t know the others in their group,” said de Dreu. “Oxytocin is causing a more general shift from self-interest to group-interest. It’s simplistic and wrong to call oxytocin a ‘moral’ molecule.”

S. Shalvi and C.K.W. de Dreu, “Oxytocin promotes group-serving dishonesty,” PNAS, 10.1073/pnas.1400724111, 2014.

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Avatar of: Roy Niles

Roy Niles

Posts: 115

April 1, 2014

Oxytocin doesn't "cause" anything in the sense that in and of itself it has a causative purpose.  It serves the purposes of other causative agents that are capable of deciding to make use of its signaling poperties.  It's a chemical that the brain has been functionally instructed to respond to pleasurably.  So obviously it can be used by a manipulator to serve, depending on the point of view, either moral or immoral purposes.

Avatar of: W. Boernke

W. Boernke

Posts: 18

April 3, 2014

The notion that humans are moral because morality is the result of natural selection acting on genes (e.g., the gene for oxytocin) is the naturalistic fallacy (defining good as some natural property).

If you can show that oxytocin promotes behaviors such as: trust, empathy, and cooperation, you still can ask the question: are trust, empathy, and cooperation good things or bad things?

Avatar of: Hugh-F-61


Posts: 75

April 9, 2014

Oxytocin is produced in response to in-group activities and promotes solidarity and participation. The first to be discovered was reproductive- cooperation with / care for mate and offspring. This just enlarges it to include extended family, but with the same evolutionary advantage, increased security to collect food and to reproduce. The activities of the tribe (or mob) could include massacre of an adjacent tribe to take their territory, and may involve risk and self-sacrifice. Oxytocin presumably acts to bias the "conscious" decision making circuits towards joint action and less selfishness. It presumably helps to explain heroic self sacrifice and suicide bombing, as much as it encourages food sharing in times of famine.

Avatar of: PRice


Posts: 9

February 20, 2015

This study findings that “the hormone oxytocin promotes group-serving dishonesty” cannot apply generally because its subjects were ALL men.

The study should have been informed by other studies’ findings that: “..oxytocin modulates brain activity differently in male and female subjects.”

The researchers should also have been better informed about brain areas and differing reciprocal behaviors. How can the study support a finding that: “.. dishonesty to be plastic and rooted in evolved neurobiological circuitries..” when this study performed NO measurements of “neurobiological circuitries?”

Which makes me ask – What was the agenda in play here? Did the female Princeton peer reviewer really believe that this study advanced science?


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