People who believe in conspiracy theories tend to be overconfident in their own abilities, and they dramatically overestimate how many others share their views. That is the conclusion of eight studies by psychologists who propose that overconfidence, rather than a craving to feel special, helps keep fringe beliefs alive.
The paper, “Overconfidently Conspiratorial: Conspiracy Believers are Dispositionally Overconfident and Massively Overestimate How Much Others Agree With Them”, is by Gordon Pennycook of Cornell University and the University of Regina, Jabin Binnendyk of Cornell University, and David G. Rand of the Massachusetts Institute of Technology. It was published online in Personality and Social Psychology Bulletin on May 24, 2025.
Measuring overconfidence without the usual trap
Across the eight studies, 4,181 US adults recruited online rated a range of conspiracy claims and took cognitive tests, then estimated how well they had done.
A common problem with measuring overconfidence is that people who are bad at a task look overconfident simply because they did badly. To get around this, the team used a perception test in which a fuzzy image flashes briefly on screen and participants guess what it showed. The task is so hard that everyone is essentially guessing, so believing you did well says more about your disposition than your skill.
Conspiracy believers consistently overestimated their performance on numeracy and perception tests, even after accounting for how well they actually did. The link held when the researchers controlled for analytic thinking, the need for uniqueness and narcissism, and it was strongest for the most fringe conspiracies.
The gap was large in practical terms. In the first four studies, people below the median on overconfidence rated between 19 and 39 percent of the conspiracies as true. Those above the median rated between 28 and 66 percent as true.
A false sense of consensus
The later studies asked participants whether claims were true and then how many other people agreed with them. The results were stark. Conspiratorial claims were believed by a majority of participants only 12 percent of the time, but believers thought they were in the majority 93 percent of the time, an overestimate of more than four times.
In the final study of 927 people, the authors added a stress test. Democrats were asked how many Republicans agreed with them about conspiracies, and vice versa. Even then, believers overestimated agreement, which the authors read as evidence that conspiracists are genuinely unaware that their beliefs are on the fringe.
Overconfidence, but not analytic thinking, narcissism or need for uniqueness, predicted this false consensus.
What the authors caution
The researchers list several limits. Most of the work was correlational. All participants were Americans recruited from online survey panels, and the most deeply distrustful people may avoid taking part in university studies at all. They also note that estimating overall performance may differ from how confident people feel about each individual belief.
The authors contrast two accounts. One holds that people believe conspiracies because they want to stand out. Their data point instead to a quieter mechanism: believers may never seriously consider that they could be wrong, and assume most people see the world as they do.
Study Details:
- Title: Overconfidently Conspiratorial: Conspiracy Believers are Dispositionally Overconfident and Massively Overestimate How Much Others Agree With Them
- Authors: Gordon Pennycook, Jabin Binnendyk, David G. Rand
- Journal: Personality and Social Psychology Bulletin, Vol. 52, No. 8, pp. 2509-2528
- Publication Date: May 24, 2025
- DOI: 10.1177/01461672251338358