JAMES TILLEY MATTHEWS feared the Air Loom Gang. In 1797, he claimed that this mysterious group of villains could and manipulate “the magnetic fluid” to force him to smile. The gang was a figment of his imagination, but Matthews’s insistence that he was being persecuted saw him admitted to a psychiatric hospital in London. Today, many researchers . In the 200 years since, the broad assumption has been that paranoia of the kind Matthews experienced is a symptom of a severe mental health condition. But attitudes are now changing.
Research over the past 20 years has revealed that paranoia isn’t restricted to a subset of the people who have been diagnosed with schizophrenia or similar conditions. Some researchers argue there is, in fact, a paranoia spectrum, and perhaps 1 in 6 of us may fall somewhere along it. Even more remarkably, the number of people prone to paranoid thoughts rose as covid-19 spread across the world.
Such discoveries have prompted psychologists to take a fresh look at paranoia, including its overlap with conspiracy theories such as QAnon. The research has led to the intriguing idea that mild paranoia, far from being undesirable, may be an evolved condition that worked to the advantage of our hominin ancestors – and still benefits us today. The work has also brought us closer to working out why we might end up on the paranoia spectrum and, if we do, identified some simple changes we could make to our lives to protect ourselves from going too far.
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What is paranoia?
Paranoia, simply defined, is the unfounded belief that others are trying to hurt you. Such unjustified thoughts may include fear of a physical threat or merely the idea that other people are laughing at you behind your back. In some ways, this makes paranoia similar to belief in conspiracy theories (see “The overlap between paranoia and conspiracy theories”). For instance, a believer in such ideas usually suspects that actors are engaged in harmful plots, although for conspiracy theories the target is society at large rather than the individual.
Historically, paranoia has often been talked about as a symptom associated with certain severe psychiatric conditions, says , founder and director of the Center for Green Psychiatry in Texas. But this is no longer the case. “Almost anyone can end up having these kinds of irrational thoughts, even if they haven’t been diagnosed with a mental health condition,” says Brown.
In a 2011 study of some 7200 people, for example, at the University of Oxford and his colleagues discovered that that there were times over the preceding year when they felt people were against them. The study didn’t establish whether the respondents really were being persecuted or experiencing paranoia, but from Freeman’s broader research he has been able to establish figures on the prevalence of the condition.
“About 1 per cent of the population have experiences of clinical delusions [that involve paranoia] and are likely to be seen in psychiatric settings, but that is very much the tip of the iceberg,” says Freeman. “Somewhere between 1 and 3 per cent of people experience a similar level of severe paranoia although they have never received a diagnosis. And then a further 10 to 15 per cent of people experience milder paranoid thoughts.”
Over the past decade, Freeman has begun studying what he calls the paranoia spectrum, defined by the frequency and severity of paranoid thoughts. He says that many of us have the potential to develop paranoia depending on what is going on in our lives.
Why are people so susceptible to paranoia? at University College London has a surprising answer. She suspects that an innate tendency for mild paranoia might have been beneficial for survival throughout human evolutionary history – and continues to be so even today.
Raihani points out that humans are extraordinarily cooperative. Under the right circumstances, we can benefit from collaborating with people who don’t belong to our families or social groups. But cooperating with strangers carries the risk of exploitation, so it pays to be on guard in case collaborators from outside your social group – or what Raihani calls your “coalition” – plan to harm you. “I think of paranoia as being integral to our understanding of what it means to be a social species,” she says.
Raihani says existing evidence supports her hypothesis. For instance, one 2016 study examined the link between in a group of volunteers living in London. The researchers found that the more a volunteer felt discriminated against, as assessed by a questionnaire, the more likely they were to assume that avatars they encountered in a virtual reality simulation intended to upset or distress them. But Raihani and her colleagues have taken the idea further: in a 2018 study, they managed to manipulate volunteers’ social expectations in a way that .
In their lab-based study, Raihani’s team asked US-based volunteers to participate in an online game. In each round of the game, the volunteer watched as a second player – labelled the “dictator” – was presented with $0.50 and given a choice: split the money 50:50 with the volunteer or keep all the money for themselves. After each round, the volunteer was asked to evaluate the dictator’s decision. Had they acted in self-interest, just trying to make more money? Or was the dictator motivated by a desire to harm the volunteer’s ability to earn?
In reality, there was no way for the volunteer to understand the dictator’s motives. However, if Raihani’s team revealed that the volunteer and dictator belonged to the same social class or shared the same political beliefs, the volunteer was more likely to assume that the dictator was motivated merely by self-interest. In contrast, if the researchers revealed that the dictator belonged to a higher social class than the volunteer or held different political beliefs, the volunteer was much more likely to believe that the dictator’s decision was based on a desire to actively harm them. In other words, the volunteer began to experience paranoia.
Raihani wasn’t surprised by this result. “You can think of the general tendency to experience paranoid thoughts as a bit like a volume dial on the radio,” she says. “If humans have this ability for a reason, it would need to go up and down based on what you are experiencing. Exposing people to a mild social threat is the kind of thing that turns the dial up for most people.”
Not everyone sees paranoia as a trait we have evolved for its adaptive benefits in social settings. isn’t even convinced paranoia is triggered exclusively by social interactions. He says paranoia is better defined as mistrust of the world in general. It is because social connections are such an important and conspicuous part of our lives, says Corlett, that paranoia is typically associated only with a sense of mistrust and suspicion of other people.
One of our brain’s most important jobs is to use cues from the environment to predict what will happen next, to help us better navigate an uncertain world, says Corlett. He believes that paranoid thoughts occur when the brain comes up short in its predictive capabilities. This idea implies that paranoia may become more prevalent if life becomes more volatile and unpredictable – which is exactly what Corlett discovered is happening. “When the world changes, as it did with the covid-19 pandemic over the past few years, we see that people became more paranoid,” he says.
Corlett could examine this trend because he was involved in researching the causes and prevalence of paranoia before covid-19 began spreading across the world. In work carried out before the pandemic but published in 2020, Corlett and his colleagues asked volunteers in the US to participate in online games, including some that involved no social interaction. In one game, for example, the volunteers were presented with three virtual decks of face-down playing cards. To obtain a high score, they had to use trial and error to work out which deck tended to yield cards with the greatest value. As an added challenge, the volunteers were told that the deck offering the best chance of scoring highly would change at random points during the game.
Corlett and his colleagues also asked each volunteer to complete a standard psychological questionnaire to assess whether or not they were prone to paranoid thoughts. They found that volunteers assessed as being vulnerable to paranoia switched between decks so often that they performed poorly on the game. The researchers think that these volunteers mistrusted the cards, viewing them as far more unpredictable than they really were. This means they that would have helped them identify – and stick with – the high-scoring deck at that time.
Then came the pandemic. Across the world, governments introduced unprecedented policies, particularly lockdowns and face mask mandates. The familiar world became unpredictable. Corlett and his team recruited new volunteers and continued their experiments. They found that the proportion of volunteers assessed via questionnaire as prone to paranoia was than before. They also continued to see a correlation between paranoia and poor performance on the card game. This means it is possible that some volunteers began to have paranoid thoughts after the lockdown began, and simultaneously lost some of their ability to respond appropriately to environmental cues.
Although Raihani and Corlett have developed distinct explanations for paranoia, they both identify common ground between their hypotheses – particularly the idea that paranoia is at least partly about making predictions from social cues.
Even so, neither hypothesis can yet explain exactly how mild paranoid thoughts relate to the sort of persecutory delusions associated with severe psychiatric conditions. Raihani suggests it may come down to gradually losing sensitivity to social feedback. Corlett says people with more extreme forms of paranoia may experience fundamental issues with the learning mechanisms responsible for updating their beliefs about an ever-changing world.
Nor is it yet completely clear from either hypothesis how to help people struggling with paranoid thoughts. But other research does offer some clues.
Several studies have now demonstrated that excessive worry, sleep disturbances, trauma or low self-esteem all contribute to paranoia. at Vanderbilt University, Tennessee, says when you can help people manage these issues, you can reduce paranoia – even in people with severe psychiatric conditions. “It’s a very simple strategy,” she says. “But when you can reduce those worrisome thoughts in people, taking that time to build meaningful activities into their lives instead, they don’t need the paranoia.”
Freeman’s research supports this point. His team has found it is possible to reduce paranoia in people with persecutory delusions by asking them to schedule “” during which they are permitted to worry. Outside of those periods, if they felt prone to intrusive thoughts, they were asked to instead engage in healthy activities, like going for a walk or spending time with loved ones.
It is even possible to use online tools to help some – although not all – people with these intrusive thoughts. In a 2017 study, Freeman and his colleagues found that online cognitive behavioural therapy that improves sleep can also help reduce feelings of paranoia.
“When people are struggling with paranoia, they are spending too much time going over the suspicious and paranoid thoughts – and they get reinforced. That’s what pushes us along the spectrum,” says Freeman. This is why techniques to limit those thoughts are helpful.
“If you are feeling more depressed, you are having problems sleeping or your self-esteem is going down, that is going to increase your vulnerability to paranoia,” says Freeman. “The route to treating the paranoia is helping people manage these other mechanisms – that is what is going to help the most.”
A place for pronoia?
If our internal cognitive systems can be hijacked to make us think everyone is out to get us, perhaps they could be pushed in the opposite direction. Forty years ago, Fred Goldner at Queens College, City University of New York, suggested that . He termed this pronoia, or the persistent, inaccurate belief that everyone is secretly conspiring to help you. While, theoretically, it is possible that such a condition could exist – and certainly the odd – there isn’t much research to support the idea.
The evolutionary model of paranoia developed by Nichola Raihani at University College London and her colleagues (see main story) may not be compatible with pronoia. “You can think about this in terms of error management theory,” says Raihani. Mistrusting someone by mistake – paranoia – may carry a small cost. But the cost of trusting someone by mistake – pronoia – may be far higher. “Evolution favours mechanisms that err on the side of caution,” she says.
The overlap between paranoia and conspiracy theories
QAnon supporters believe a group of Satanic, cannibalistic paedophiles plotted against Donald Trump during his time as US president. Why do some people find such conspiracy theories so alluring? The study of paranoia may provide some clues.
In a recent study, Philip Corlett and Praveen Suthaharan at Yale University found a between people who have paranoid thoughts and those who believe at least one conspiracy theory. The pair then investigated the individuals’ social networks to better understand how conspiracy theories might proliferate in people with mild or more severe levels of paranoia.
“We expected that more paranoid people who believed these theories would be lonelier and more isolated,” he says. “The result we got was the opposite: they believe other people share their beliefs.” Supporting a conspiracy theory was a positive thing for them, he says.
So, given this benefit, is it possible to steer a friend or loved one away from an easily debunked theory? It’s not easy, says Corlett. He advises against directly challenging the individual, but instead suggests asking them to come up with potential alternative explanations for their theory. “Forcing your explanation on them is likely to backfire on you,” he says. “So meet people on their level, without ridiculing them, and try to find some common ground. That’s always a good place to start.”
Kayt Sukel is a science journalist based in Texas
