Nearly everyone would like to believe the news that proves them right and ignore the reports that prove them wrong. Recent research suggests that this confirmation bias prevents people from being skeptical and makes them potentially more likely to spread lies on social media.

However, in a paper in the American Economic Review, authors Marta Serra-Garcia and Uri Gneezy take a step back and show that individuals are overconfident in their ability to detect lies even without the motivation to believe them.

In an experiment, the authors first incentivized a group of participants (“senders”) to record short videos to convince others that they were seeing and describing a true news event. In one case, the senders were looking at a real headline and picture from The New York Times. But in another case, they were viewing a blank screen. The researchers then asked a different group of participants (“receivers”) to guess whether the sender was describing a real news story or was lying. 

The receivers were hardly better than a coin flip at detecting lies, but believed they were right about two-thirds of the time.

These receivers were then either incentivized to share true videos or to share videos that they thought would be believed by a second group of receivers, regardless of whether the video was true or not.

Figure 4 from the authors’ paper shows how often the first group of receivers shared lies under the two scenarios.

Figure 4 from Serra-Garcia and Gneezy (2021)