More than 1 in 3 Americans believe that the Chinese government engineered the coronavirus as a weapon, and another third are convinced that the Centers for Disease Control and Prevention has exaggerated the threat of COVID-19 to undermine President Donald Trump.

The numbers, from a survey by the University of Pennsylvania’s Annenberg Public Policy Center, underscore a moment when a particular brand of conspiracy theory is emerging in the mainstream: A belief that the “official story” is in fact a Big Lie.

At its extremes, these theories include cannibals and satanic pedophiles, (courtesy of the so-called QAnon theory); lizard-people, disguised as corporate leaders and celebrities (rooted in alien abduction stories and science fiction); and, in this year of the plague, evil scientists and governments conspiring to use COVID-19 for their own dark purposes.

Estimates of how many Americans believe at least one discredited conspiracy theory hover around 50%. But psychologists do not have a good handle on the types of people who are prone to buy into Big Lie theories.

In the most comprehensive analysis yet of people who are prone to conspiracy beliefs, researchers sketched out personality profiles that appear to be distinct. One is the injustice collector, impulsive and overconfident, eager to expose naiveté in everyone but themselves. Another is a more solitary, anxious figure, moody and detached, perhaps including many who are older and living alone. The analysis also found, at the extremes, an element of real pathology — of a “personality disorder,” in the jargon of psychiatry.

“With all changes happening in politics, the polarization and lack of respect, conspiracy theories are playing a bigger role in people’s thinking and behavior possibly than ever,” said Shauna Bowes, a research psychologist at Emory University who led the team. “And there was no consensus on the psychological bases of conspiracy beliefs. In this work, we tried to address that.”

Conspiracy theories are as old as human society, of course, and in the days when communities were small and vulnerable, being on guard for hidden plots was likely a matter of personal survival, some scientists argue. In the modern era, scholars like Theodor Adorno and Richard Hofstadter have identified conspiracy beliefs and paranoia as central elements in political movements.

Psychologists have picked up the topic in earnest only in the past decade or so. People often adopt conspiracy beliefs as a balm for deep grievance. The theories afford some psychological ballast, a sense of control, an internal narrative to make sense of a world that seems senseless.

The belief that drug companies invent illnesses to sell their products, for instance, can provide a way of processing a grave and unexpected diagnosis. The advent of the pandemic, and its injection into partisan politics, lend an urgency to a deeper understanding of conspiracy theories, given that false beliefs — that the CDC is politically compromised — can lead millions to ignore public health advice.

“You really have a perfect storm, in that the theories are directed at those who have fears of getting sick and dying or infecting someone else,” said Gordon Pennycook, a behavioral scientist. “And those fears distract people from judging the accuracy of content they may read online.”

In the new study, titled “Looking Under the Tinfoil Hat” and posted online in the Journal of Personality, Bowes and Scott Lilienfeld led a team that measured which facets of personality were most strongly correlated to higher levels of susceptibility to conspiracy beliefs. The findings were at least as notable for the associations revealed as for those not found. For example, qualities like conscientiousness, modesty and altruism were very weakly related to susceptibility. Levels of anger or sincerity bore no apparent relation.

The personality features that were solidly linked to conspiracy beliefs included some usual suspects: entitlement, self-centered impulsivity, coldheartedness (the injustice collector), elevated levels of depressive moods and anxiousness (the moody figure, confined by age or circumstance). Another one emerged from the questionnaire that aimed to assess personality disorders — a pattern of thinking called “psychoticism.”

Psychoticism is a core feature of so-called schizo-typal personality disorder, characterized in part by “odd beliefs and “paranoid ideation.” It is a milder form of psychosis. It’s a pattern of magical thinking that goes well beyond garden variety superstition.

“As a rule, people don’t want to spread false content,” Pennycook said. “But at a time like this, when people are worried about the virus, headlines like ‘vitamin C Cures COVID’ or ‘It’s All a Hoax’ tend to travel widely. Eventually, these things reach the Crazy Uncle, who then shares it” with his like-minded network.

Conspiracy theories about government plots will probably never go out of style, and at some level they function as safeguards against real conspiracies. As for the bloodsucking, cartoon versions, those are likely to be keepers too, the research suggests. They have a core constituency, and in the digital era its members are going to quickly find one another.