July 20, 1969: Buzz Aldrin walks on the surface of the moon.  Neil  Armstrong, taking the photo,  is reflected in his visor
Some people believe the moon landings were faked. Nasa

In the internet age has been a boon for the spread of conspiracy theories – such as the idea that the moon landings were faked, or that the US government planned 9/11.

For non-believers, it is tempting to write off people who engage with these ideas as being less intelligent. However, new research which examined why some people are inclined to believe in seemingly irrational beliefs, suggests the reality is not so simple.

"We show that reasonable scepticism about various conspiracy theories and paranormal phenomena does not only require a relatively high cognitive ability, but also strong motivation to be rational," said Tomas Ståhl, lead author of the study from the University of Illinois at Chicago.

"When the motivation to form your beliefs based on logic and evidence is not there, people with high cognitive ability are just as likely to believe in conspiracies and paranormal phenomena as people with lower cognitive ability."

Previous research has suggested that people with higher cognitive ability – in other words, a more analytical thinking style – are less likely to believe in conspiracies and the paranormal.

For the study, published in the journal Personality and Individual Differences, Ståhl and his co-author Jan-Willem van Prooijen from Vrije Universiteit Amsterdam conducted surveys involving more than 300 people to assess their analytic thinking capabilities, as well as factors that might promote scepticism toward unfounded beliefs.

The results showed, as you may expect, that an analytic cognitive style was associated with weaker belief in the paranormal and conspiracies. But crucially this was only the case among participants who placed a high value on forming their beliefs based on logic and evidence.

For those who did not value this, having a more analytical thinking style was not associated with weaker beliefs in conspiracies and the paranormal.

The researchers note that despite increased educational opportunities and intelligence scores in the US population, unfounded beliefs remain commonplace.

"Our findings suggest that part of the reason may be that many people do not view it as sufficiently important to form their beliefs on rational grounds," Ståhl said. "Many of these beliefs can, unfortunately, have detrimental consequences for individuals' health choices, as well as for society as a whole."