Lie scientists

Who lies the most

Meta-analysis summarizes 565 studies on the psychology of dishonesty

From cheating on tax returns to major corruption scandals - people keep lying to gain advantage. Experimental studies investigate which personal and environmental factors make people liars. Scientists from the Max Planck Institute for Human Development and the Technion - Israel Institute of Technology have carried out an extensive meta-analysis on lying, which summarizes the findings from 565 studies. The results show, among other things, that the tendency towards dishonesty depends on age and gender.

The basic conflict of any lie is the choice one has. Either you are honest and forego advantages or you lie in order to get more money, power or fame, for example. Why people lie depends on personal and environmental factors. In order to investigate this empirically, this basic conflict was simulated in simple experiments in many published studies. For example in the form of the coin tossing game. Test subjects toss a coin without anyone watching them. They pass the result on to the test supervisor, for example by computer. With heads you get money, with numbers you get nothing. If you carry out this experiment more often and with many test persons, the ratio of heads to tails should be fifty to fifty in total. However, almost all studies show that test subjects call heads more often than tails. That means: at least some test persons lie in order to “earn” more money.

Numerous studies with this or a similar basic structure have been carried out by scientists in the last ten years in order to investigate the various factors that lead to dishonesty. Do nuns lie more often than prison inmates? Are you more likely to lie online or on the phone? Are you more likely to lie when you expect more money? For the meta-analysis, the scientists from the Max Planck Institute for Human Development and the Technion - Israel Institute of Technology took into account the data from 565 studies with a total of 44,050 test subjects. “Although there are numerous studies that investigate who is lying, when and why, the results are inconclusive, and in some cases even contradictory. With the help of the large amount of data from all studies, we can now make clearer statements about some factors, ”says Philipp Gerlach, Associate Scientist at the Max Planck Institute for Human Development and first author of the study.

In total, 42 percent of all men and 38 percent of all women lied in the experiments examined. The study was thus able to confirm the assumption that men lie more frequently than women - even if the difference is only small. In addition, younger people lied more often than older people. The probability that someone will lie decreased by 0.28 percentage points every year. While it is around 47 percent for a 20-year-old, it is only 36 percent for a 60-year-old. The study was unable to confirm other factors that have been discussed again and again. For example, the scientists find no indication that business students lie particularly often.

Published and as yet unpublished studies from psychology and economics were used for the meta-analysis. These studies examined the extent of dishonesty using a few, but very different, experimental set-ups. In some, dishonesty referred to a chance outcome, such as the coin tossing game. In other studies, dishonesty related to the level of one's skill, such as whether a math puzzle was solved correctly. The researchers were able to show that such structural differences in the experimental setup influence the behavior of the test subjects and thus lead to different results on the extent of dishonesty. "If you want to know to what extent people are inclined to behave dishonestly, you have to take into account the experimental situations and temptations people are confronted with," says Ralph Hertwig, director of the "Adaptive Rationality" research area at the Max Planck Institute This suggests that dishonesty is not just a characteristic of a person, but rather interacts systematically with the conditions of the environment.