“Someone must have slandered Josef K., for one morning, without having done anything wrong, he was arrested.” So begins Franz Kafka’s The Trial, a novel Kafka worked on between 1914 and 1915 but never finished. It was saved from oblivion by his friend Max Brod. Disobeying Kafka’s orders to burn his manuscripts after his death in 1924, Brod edited the text of The Trial and published it in 1925.

What is the charge against Josef K.? We don’t know. Kafka’s diary declares him “guilty” but does not explain the crime. Nor does the novel provide any enlightenment. Indeed, when Josef K., a chief clerk at a bank, finally gets around to questions, they have nothing to do with the accusation itself. “The main question is: Who’s accusing me? What authorities are in charge of the proceedings?” he asks an inspector. He gets no answers.

From the outset, Josef K. is plunged into the throes of uncertainty and suspicion, which will continue to dog him as he—left at liberty as he awaits trial—attempts to arrange for a defense and find his way to hearings that have no specific time or room location. As we follow K.’s misadventures, we have the disquieting feeling that this menacing world may be nothing more than the external projection of his internal paranoia: the baseless conviction that others deliberately wish us ill will. That, at any rate, is one possible reading (among countless others) of this curious novel. Beyond the psychological interpretation are the existential (K.is simply guilty of existing); the theological (it is the original sin that is on trial) and the political (Kafka is presaging the arbitrariness of totalitarian regimes). The narrative—simultaneously ambiguous, vague, abstract and bizarre—admits any number of approaches.

Psychologists like me naturally incline to the psychological point of view, however, and see K. as a compelling example of what it is like to suffer from paranoia. We have learned a great deal about how common the problem is and know something about how it arises, but we hope that further study will bring more clarity as well as better therapies.

A Mental Kafkesque World

The Trial, like Kafka’s other works, suggests that the paradoxes and bottlenecks characteristic of the faceless bureaucratic systems that make people’s lives impossible are not always inherent in the systems themselves. Rather in Kafka’s books, these “Kafkaesque” attributes exist in the minds of his protagonists. It is the human brain that makes a situation seem Kafkaesque.

For instance, in the absence of clear information or guidance, K. himself is the one who initiates many of the steps he takes in The Trial. In fact, he is the source of everything that is happening, although he seems unaware of it. Notably, when he tries to find the right interrogation room, he reasons: “The court was attracted by guilt, from which it actually followed that the room for the inquiry would have to be located off whatever stairway K. chanced to choose.” And, naturally, there it is.

The world of The Trial—with its endless corridors, vertiginous stairs, illogical twists, stifling rooms—caneasily be seen as a reflection of the mental world of a paranoid person. And K.’s behavior is typical of paranoia: he is extremely sensitive to glances, laughter, whispering and gossip. He suspects people of making fun of him and of talking about him using “secret signals.” He constantly feels vaguely threatened. Soon his whole life and the entire world are involved in the trial, to his great despair.

Pages from the original manuscript of Franz Kafka’s ‘The Trial’ are on display at the exhibition ‘Franz Kafka—The entire Trial’ at Berlin’s Martin Gropius Bau museum on June 28, 2017. Credit: John MacDougal Getty Images

The Paranoia Continuum

The Trial is surprisingly captivating. Like K., readers want to understand what is happening, what he is accused of, who his mysterious persecutors are and, of course, how it will all end. Why is it so easy to get caught up in the logic of this character? If we find ourselves asking the same questions as he does, it is because his brain is not so different from ours: we understand intuitively how paranoia works.

Paranoia was long considered exclusively a marker of severe psychotic states. But today it is seen as a continuum. For example, some people are mildly suspicious that others disapprove of them. Others feel they are being secretly observed. Still others perceive imminent threats from malevolent individuals. Finally, people at the end of the spectrum are convinced that powerful and evil forces are aligned against them (referred to as persecutory delusions, a term popularized by French psychiatrist Henri Legrand du Saulle in 1871). Sometimes these individuals suffer from hallucinations.

Paranoid thinking is estimated to occur regularly in 10 to 15 percent of the general population, and up to 3 percent have paranoid delusions that are comparable in severity to the delusions suffered by patients with schizophrenia. Interestingly, studies based on surveys suggest that people who feel paranoid in one situation often feel that way in other situations as well: if you think that aliens are about to kidnap you, you also tend to think that your co-workers are looking at you a little strangely and that the laughter you hear coming from the cafeteria is about you. It is as though the paranoid ideas join to create a world completely and utterly centered on you—in other words, Josef K.’s world.

But how do you get to that point? It is only natural to care about what others are saying about you and expect from you. It is better to know if someone you encounter is a friend or an enemy; when in doubt, assuming a person is an enemy protects you from betrayal. The problem is that this vigilance, which is fundamental to human cognition, easily becomes deranged if it is constantly engaged. In paranoid people, it results in disordered social interactions. Because we cannot read the thoughts of others, we make guesses by interpreting their words and behavior; people who are paranoid consistently tinge this gathering of clues with mistrust.

The Brain’s Hyperactive Threat Detector

Studies of twins show that paranoia is explained roughly equally by genetic characteristics and by such childhood traumas as abuse or any form of exclusion and mistreatment. Other studies have shown abnormal activation in the brain circuits involved in reading social signals, particularly the amygdala. This part of the brain, which detects potential threats and the strength of various stimuli, is hyperactive in people with paranoia. Another common feature, which Josef K. displays, is difficulty escaping persecutory delusions. This difficulty suggests that paranoid individuals have undergone mental changes that cause them to jump to conclusions too quickly and to then struggle to let go of their convictions. They are said to suffer from cognitive rigidity: all of their reasoning abilities are invested in the effort to cling to their beliefs. When asked, two thirds of people with paranoia are unable to provide any objective reason for why others might be persecuting them, other than pure malice.

University of Oxford psychiatrist Daniel Freeman has done much to clarify the interactions among the various factors that contribute to paranoia. Together with computer scientists, he has created virtual-reality environments that offer the advantage of full control over experimental parameters. In one experiment, for example, the VR environment consisted of an underground train ride where computer characters (avatars) whispered, laughed and reacted to the study participants’ gaze. The researchers configured these avatars to behave in neutral ways so that participant concerns about being spied on or made fun of by definition constituted paranoid thinking.

Are We All Paranoid?

The researchers found that more than 40 percent of participants had at least one such thought—further confirmation that many people are inclined to paranoid thinking, even if not on a regular basis. Thanks to a battery of measures relating to the psychology and experiences of the participants, the investigators also showed that the frequency of these thoughts is higher in anxious individuals who are also very sensitive to the opinions of others, exhibit cognitive rigidity or have endured a number of distressing experiences (such as abuse).

Researchers still want to know more about the genetic, neurobiological, cognitive, social and psychological factors that combine to cause paranoia. In the meantime, Freeman and his colleagues are testing virtual reality for therapy. Through VR immersion, the researchers teach patients to reinterpret their paranoid thoughts and to feel less threatened. The mechanism allows gradual exposure to troubling stimuli: ever more people in the subways, ever louder conversations. It is even possible to distort reality to re-create what patients believe they perceive—for example, whispering and laughter. A century ago Kafka replicated the paranoid experience through the lens of literature. Today researchers are doing it with technology.