“I want you all to know that we are fighting the fake news. It’s fake, phoney, fake. A few days ago, I called the fake news the enemy of the people. And they are. They are the enemy of the people …”

Donald Trump’s assault on “terrible, dishonest” journalists (“the lowest form of life”) has become one of the hallmarks of his fledgling administration. But as many have noted, this posturing echoes developments closer to home. It was Michael Gove, of course, who claimed during the Brexit campaign that “people in this country have had enough of experts”.

Scott Pruitt, the new chief of the US Environmental Protection Agency, certainly seems comfortable dismissing scientific consensus: “I believe that measuring, with precision, human activity on the climate is something very challenging to do, and there’s tremendous disagreement about the degree of impact. So, no, I would not agree that it’s a primary contributor to the global warming that we see.”

From a certain perspective, this is knockabout political theatre. And a little scepticism is prudent, for sure. Blithely accepting whatever we’re told is clearly unwise. Information can be unreliable; cover-ups do occur. But if we dismiss everything we hear in the media, if we assume that scientists and scholars are untrustworthy, we leave ourselves vulnerable to manipulation, misinformation, and rumour. This makes us wonder: are we entering a golden age of the conspiracy theory?

Not that this type of cognitive error is new, of course. The idea that individuals or groups have conspired to commit some crime and then cover it up reaches back centuries — witness, for example, the belief that Jews were poisoning wells and killing Christians or that Roman Catholics were secretly plotting to undermine the Protestant English state. However, if we’re now living in a “post-truth” society, with traditionally trusted sources of information routinely undermined and informal communication possible like never before via the Internet, one of the dubious fruits of this febrile climate may be a growth in the power and reach of conspiracy theories.



What makes such ideas so credible for some people? Why, in the face of all available evidence and despite apparent public consensus to the contrary, would a person believe that the moon landings were faked, that the Aids virus was created by the US government, or that the British security services murdered Princess Diana to prevent a marriage to the Muslim Dodi Al-Fayed? Are some groups more likely to endorse conspiracy theories than others? And, if so, what do we know about the characteristics of these people?



As we discovered when we went looking for answers to these questions, specific scientific studies of conspiracy beliefs are few and far between. And so we began by seeing what we could discover from general epidemiological surveys, mining their findings in search of associations between particular social and psychological factors and a belief in conspiracy theories. With Richard Bentall of the University of Liverpool we turned to the rich dataset of one of the largest surveys of psychological health ever carried out: the US National Comorbidity Survey-Replication. The NCS-R is a few years old now: it was carried out in 2001-03, predating the current skeptical turn. But it was large, nationally representative, and scientifically robust. The results of our research are published today.



The NCS-R covers a lot of ground, but one of the statements participants were asked to consider was this: “I’m convinced there’s a conspiracy behind many things in the world.” More than a quarter of those who responded to the item felt that it was true – a statistic that provides food for thought in itself. And that was fifteen years ago.



These people had several things in common. They were, for example, more likely to be male and unmarried. But what really struck us were the above-average levels of social disadvantage. Here was a group with lower levels of education and income. They were more likely to be from an ethnic minority. They were more likely to carry a weapon. Religious attendance may help mitigate some of the effects of disadvantage; this group was far less likely to go to services regularly.



It wasn’t just demographic characteristics that the conspiracy theorists shared. They tended to report lower levels of physical and psychological wellbeing; and to see themselves as socially inferior, both in comparison to their local community and to the nation as a whole. They were more likely to have seriously considered suicide. Their social networks were weaker (they often felt, for example, that they couldn’t rely on friends and family in times of trouble) and they found it harder to maintain secure relationships.



Childhood relationships with parents had frequently been challenging. Often these individuals hadn’t lived with both biological parents; they’d spent extended periods away from home; or had experienced violence at the hands of their parents.



Finally, the conspiracy theorists were more likely to meet the criteria for all types of psychological disorder, including anxiety, depression, ADHD, and alcohol and drug problems.



What we see then is a clear association between a belief in conspiracy theories and a wide range of negative life circumstances and personal distress. So far an association is all it is. Do these types of problems make the people affected especially susceptible to conspiracy theories or is it the other way around? That research hasn’t been done. But our view is that the low self-esteem, smaller social networks, and marginalisation we see in so many of the US sample may play a key role at an early age, providing fertile ground for a distrust of authority: feeling that society has rejected them, they learn to reject the beliefs that society endorses.



Experiences like this in childhood may have a lasting effect on the way we make sense of the world. When an event occurs that doesn’t fit our expectations or that seems threatening, we feel anxious and disturbed. We want certainty and reassurance. Rather than thinking it through, we’re liable to jump to conclusions, to look for the answers that conform to our preconceptions rather than calmly weighing up the evidence.



The upshot of that process may be a conspiracy theory. In the short term, it’s a belief that brings benefits — in place of anxiety and uncertainty, we are soothed by what feels like knowledge. Our bruised self-esteem is boosted by the sense that we are one of the small minority who really know what’s going on. And thanks to the Internet we’re able to connect with these like-minded souls: suddenly we can feel part of a community.



Psychological models of conspiracy theories need testing, for sure. Indeed, we don’t know enough about conspiracy theories full stop. But given the current socio-political climate has this kind of research ever been more necessary?



Daniel and Jason can be found on Twitter as @ProfDFreeman and @JasonFreeman100.