Science Proves People Lies for Selfish Reasons

If the lie's outcome was delayed or unclear, people lied less often.


Almost everybody, at some instant, has lied. Some lie for many reasons that can affect another person. And few lie almost all the time. Scientists from the University of Zurich tried an experiment to see how honest people would be. They want to know if they could affect behavior with transcranial direct current stimulation (tDCS). The tDCS is a noninvasive electrical pulse that apparently makes brain cells more active.

Scientists noted, “Although this prevented us from identifying individual acts of cheating with certainty, we can determine the degree of cheating with each tDCS intervention by comparing the mean percentage of reported successful die rolls against the 50% benchmark implied by fully honest reporting.”

They experimented, i.e., the Sham experiment, where they targeted the right dorsolateral prefrontal cortex that involves risk and moral decision-making along with the tDCS. Scientists just wanted to see how people react while reporting to dice rolls.

There were ten rolls used in an experiment. But before reporting to roll, scientists used a computer to tell the participants which types of rolls would get them the most money.

READ: Lying Changes Your Brain, So Dishonesty Makes You Feel Less Guilty

The participants reported successful die rolls 68% of the time, whereas the honest people reported 50% of the time. It suggests that many participants lied to someone but not on all possible occasions. But when scientists increased the neural excitability with tDCS, they found that the cheating rate was substantial in a control condition and decreased dramatically.

During the non-sham experiment, scientists reduced the electrical stimulation with tDCS. This time, participants only reported successful die rolls 58 percent of the time.

Scientists noted, “This result corresponds to an implied cheating rate of 15 percent. This is a figure that is nearly 60 percent lower than that observed in the sham condition.”

Scientists also measured selfish behavior using a dictator game and an investment experiment to look at someone’s affinity for risky and unclear results. They even tracked how impulsive someone might be.

Scientists found that “unless the lying specifically benefitted themselves, the participants were less likely to do it.”

Scientists noted that “the stimulation mainly reduced cheating in participants who actually experienced a moral conflict. But it did not influence the decision-making process” in people who were trying to make as much money as possible.”

Journal Reference

  1. Michel André Maréchal, Alain Cohn, Giuseppe Ugazio, and Christian C. Ruff; Increasing honesty in humans with noninvasive brain stimulation. Proceedings of the National Academy of Sciences Vol. 114 | No. 17 DOI: 10.1073/pnas.1614912114


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