To psychologists interested in the science of lying, Trump’s increasing mendacity presents an interesting question.
Between when President Donald Trump assumed office in January 2017 and the end of April, the average number of public false or misleading statements he has made per day has been increasing. According to the Washington Post’s fact checkers on May 1, “for the president’s first 100 days, he averaged 4.9 claims a day… since we last updated this tally two months ago, the president has averaged about 9 claims a day.”
This is a significant rise. Our calculations suggest that if the current escalation rate remains steady, by the end of his term the president could be making as many as 19 public false statements a day, on average.
To psychologists interested in the science of lying, Trump’s increasing mendacity presents an interesting question: What might be causing this growth?
We first considered whether the increase could be explained by reporting bias. In other words, perhaps more falsehoods have been reported over time, rather than actually presented by the president. We found this explanation to be unlikely, as the Washington Post fact checkers stated they have scrutinized every single tweet, speech, statement and interview by the president since last January. (Importantly, this analysis is confined to public statements and it is difficult to know whether there has been a change in Trump’s total falsehoods.)
So if not reporting bias, what can explain the temporal increase of these falsehoods? Perhaps past lies needed to be covered up by more lies, or repeated falsehoods were eventually perceived as true making subsequent repetition likely. Or maybe falsehoods led to positive consequences, reinforcing such behavior further. These are all plausible explanations. But our research points to yet another intriguing explanation — a biological process called emotional adaptation.
Emotion plays an important role in constraining dishonesty. If we feel bad when we lie, we are less likely to do so. But if this uncomfortable feeling were to magically disappear, research suggests we would in turn lie more. In one study, students who were given a pill called a beta-blocker, which reduces emotional arousal, were more likely to cheat on an exam than students who were given a placebo. In other words, without that uncomfortable physiological feeling that accompanies dishonest behavior, people were more likely to cheat.