Uncertainty aversion Automatic translate

People are more concerned about the uncertainty of the wait than the length of the wait.

Uncertainty aversion is a psychological tendency to perceive any situation with an unknown outcome as threatening and intolerable, with subjective discomfort often exceeding the discomfort of a known negative outcome. In other words, the expectation itself causes more suffering than the thing being expected.

What is uncertainty aversion?

In English-language scientific literature, this phenomenon is referred to as intolerance of uncertainty (IU). Michel Dugas, Francis Friston, and their colleagues from Laval University (Canada) first systematically described it in 1998 within the framework of a cognitive-behavioral model of generalized anxiety disorder (GAD). According to their definition, IU is "a negative dispositional characteristic arising from a set of catastrophic beliefs about uncertainty and its consequences."

This construct does not refer to a personality trait in the classical sense, but rather to a cognitive style of responding to a lack of information. A person with a high level of IU tends to perceive any situation with unfilled information "gaps" as potentially dangerous — even when there are no objective threats.

It’s important to distinguish between two concepts that are often confused. Uncertainty intolerance differs from uncertainty tolerance : the latter describes the ability to maintain functionality in the face of ambiguity, while the former describes a pathological reaction to the very absence of clarity, regardless of its content.

Historical context

From philosophy to psychology

Anxiety in the face of the unknown is one of the oldest themes in philosophical and religious thought. Augustine of Hippo, Blaise Pascal, and Søren Kierkegaard all noted the connection between the inability to predict the future and existential anxiety. However, scientific study of this phenomenon began much later, when psychologists acquired tools to measure anxiety.

In the 1950s, American psychologist Elliot Frankel-Brunswick introduced the concept of "ambiguity tolerance" in the context of research on authoritarian personalities. Later, in the 1970s and 1980s, interest in the topic intensified within cognitive psychology, as scientists began to study how incomplete information influences decision-making.

A turning point came in 1998: the research team of Dugas, Gagnon, Ladouceur, and Friston published a cognitive-behavioral model of GAD, which for the first time identified uncertainty aversion as a central pathogenetic mechanism rather than an accompanying symptom. This shifted the focus from the content of anxious thoughts to the reaction to informational uncertainty itself.

Concept development

Throughout the 2000s, the concept of IU expanded. In 2016, Norman Carlton proposed an even more succinct definition: "a basic fear of the unknown." In 2019, Ebert and Dugas updated the cognitive-behavioral model, shifting the focus from beliefs about anxiety to how a person interprets uncertainty itself — providing a more precise tool for clinical work.

The Neurobiology of Expectation

The brain in conditions of uncertainty

When a person faces uncertainty, several key brain structures are activated. The anterior cingulate cortex (ACC) and insular cortex are activated in anticipation of negative events with an unknown probability. Functional MRI studies have shown that activity in these areas correlates with subjective stress levels — not when the impact is inevitable, but precisely when its probability is at its most uncertain.

Interestingly, the amygdala — a structure traditionally associated with fear — reacts more strongly to a threat when its occurrence is unpredictable. This supports the hypothesis that the brain uses stress as a signal of environmental unpredictability, rather than actual danger.

Dopamine and reward anticipation

The dopamine system, traditionally associated with reward, also responds to uncertainty — and in a very distinctive way. Dopamine levels rise more during the anticipation period than when the reward itself is received. This explains why slot machines and lotteries are so addictive: irregular, unpredictable reinforcement creates a significantly stronger neurochemical response than a stable reward.

However, the same system operates differently under negative expectations. When a negative outcome is predicted and its probability remains unknown, dopamine neurons don’t gradually decrease their activity — they exhibit a sharp suppression, which is subjectively experienced as anxiety and motor retardation.

The anxious brain under uncertainty

A joint study by the HSE Institute of Cognitive Neuroscience, University College London, and the Max Planck Institute for Human Cognitive and Brain Research revealed fundamental differences between people with high and low levels of trait anxiety when solving probability problems. Highly anxious subjects showed higher activity in the medial prefrontal, orbitofrontal, and anterior cingulate cortex, while their task performance was lower.

This paradox — more neural activity with worse results — is explained by the fact that the anxious brain spends resources on sorting through unrealized scenarios rather than on processing actual incoming information.

Stress from uncertainty vs. stress from the inevitable

De Berker’s experiment

One of the most revealing experiments in this area was conducted by a UCL research team led by Archie de Berker, who published their results in the journal Nature Communications in 2016. The experiment involved 45 volunteers playing a computer game: turning over virtual stones, some of which contained snakes. Upon discovering a snake, the subject received a painful electric shock to the arm.

The key manipulation was the level of uncertainty: throughout the game, the probability of a snake being caught under a rock constantly changed. Subjective stress and physiological indicators — galvanic skin response, pupil dilation — correlated not with the intensity of the blows themselves, but with the level of uncertainty about whether a blow would follow.

Situations with a 50% chance of being hit were significantly more stressful than situations with a 100% chance or no chance at all. According to de Berker, "It turned out that not knowing you’ll get hit was significantly worse than knowing for sure you will or won’t get hit." Moreover, those participants whose stress levels more accurately reflected actual uncertainty were better at guessing whether there was a snake under a rock — stress apparently served as an adaptive risk-detection cue.

Temporal and probabilistic uncertainty

Research distinguishes between two types of uncertainty that trigger anticipatory anxiety. Occurrence uncertainty is not knowing whether an event will occur at all. Temporal uncertainty is not knowing exactly when it will occur.

Experiments measuring the startle response have shown that temporal uncertainty — not knowing "when" — potentiates the physiological anxiety response more strongly than probabilistic uncertainty. In other words, a person who knows an unpleasant event will occur, but not how long, experiences prolonged, persistent nervous system arousal — chronic background stress.

This result is consistent with a common anecdotal observation: many people describe the waiting period as more distressing than the actual moment of receiving bad news or a painful procedure.

Duration of waiting versus uncertainty of waiting

This is where the phenomenon highlighted in the title of this article emerges: the subjective burden of waiting is determined not so much by its duration as by the degree of uncertainty. Someone waiting three days for medical test results without any information about the timeframe experiences greater anxiety than someone who is told, "The answer will arrive in exactly one week."

Psychologically, this is explained through the concept of predictability. Certainty — even negative certainty — provides the brain with structure: it can build expectations, plan a response in advance, and "let go" before an event occurs. Uncertainty, on the other hand, keeps the threat monitoring system in constant alert mode, preventing the ability to formulate a clear response or relax.

Cognitive mechanisms

Dugas’s uncertainty intolerance model

Dugas’s (1998) model identified four interrelated components that underlie anxiety disorders: intolerance of uncertainty, positive beliefs about worry, a negative problem-solving orientation, and cognitive avoidance. The first component, the perception of uncertainty as intolerable, occupies a central place.

The mechanism works as follows. When a person with a high IU level encounters signs of uncertainty — incomplete information, unclear deadlines, vague commitments — the belief "if I don’t know what will happen, something bad will probably happen" is activated. This belief triggers worry, which the person perceives as beneficial ("I worry — it means I’m preparing"). However, worry doesn’t reduce uncertainty; on the contrary, it generates new "what if…" questions, increasing the number of unknowns.

Attention bias and the insidiousness of expectation

Under conditions of uncertainty, attention shifts to potential threats rather than neutral or positive cues. Studies using fMRI have shown that approximately 75% of participants overestimated the frequency of negative outcomes after receiving uncertain cues — a so-called covariance bias. In other words, the brain systematically "completes" a pessimistic picture when faced with uncertainty.

Furthermore, research by Gunter and McLaughlin found that waiting in uncertainty slows the subjective perception of time. One minute of waiting without information is perceived as longer than the same minute with a clear time cue. This effect increases the subjective severity of the situation, regardless of its objective duration.

Catastrophizing and tunnel vision

People with high intolerance of uncertainty experience a characteristic cognitive dysfunction under the influence of anticipatory anxiety: they fail to see analogies between the current situation and past experiences. Their accumulated experience is perceived as insufficient, as the current situation is "special" and "unfamiliar." In practice, this leads to a failure to retrieve successful coping strategies from memory and a feeling of helplessness.

This process is self-sustaining: the stronger the anxiety, the narrower the cognitive focus, the fewer resources left for searching for analogies and planning, the stronger the anxiety.

Neurobiological foundations

Behavioral inhibition system

In their neurobiological models of anxiety, Geoffrey Gray and Neil MacNaughton identified the behavioral inhibition system (BIS) as the structure responsible for responding to uncertainty. The BIS is activated precisely when environmental cues are contradictory or incomplete, not when the threat is obvious. The system’s purpose is to suspend behavior, heighten attention, and increase readiness to respond. When functioning properly, it provides a useful pause before action; when overactivated, it is a source of chronic anxiety.

A high IU correlates with chronically elevated tone of this particular system. People with a heightened intolerance of uncertainty seem to be in BIS mode constantly, regardless of the actual threat.

The role of the insula and ACC

The insular cortex registers discrepancies between expectations and reality and signals a "possible threat." The anterior cingulate cortex is involved in conflict monitoring — it is activated when multiple competing scenarios are unavailable and a choice cannot be made. In the presence of uncertainty, both structures receive excess input and are unable to exit monitoring mode.

That’s why research shows that uncertainty activates the same neural circuits as physical pain. This isn’t a metaphor — we’re talking about objectively measurable overlaps in brain network activation, documented by neuroimaging methods.

Individual differences

Who is most vulnerable?

The level of intolerance of uncertainty varies among individuals and can be measured. The most widely used scale is the Intolerance of Uncertainty Scale (IUS), developed by Friston and colleagues in 1994 and revised in 2007–2010. The scale distinguishes two components of IU: prospective (anxious anticipation of the future) and inhibitory (paralysis in the face of the need to act in the face of uncertainty).

High IU levels are consistently associated with anxiety disorders, primarily GAD, as well as obsessive-compulsive disorder (OCD), social anxiety, depression, and panic disorder. Research shows that IU is a transdiagnostic risk factor: it is not specific to one disorder but increases vulnerability to a wide range of emotional disturbances.

Gender and age aspects

Meta-analytic data indicate modest gender differences in IU: women, on average, exhibit higher scores, although the effect is small and varies significantly across samples. Age-related dynamics are less well studied, but some longitudinal data suggest that young adults (teenagers and 20-somethings) exhibit a more acute reaction to uncertainty during periods of social instability — for example, during the COVID-19 pandemic — than adults.

The pandemic as a natural experiment

The COVID-19 pandemic has provided an unprecedented opportunity to observe mass encounters with prolonged, multi-layered uncertainty. Longitudinal studies have documented that in people with high IU, symptoms of anxiety and depression increased more rapidly and remained elevated even months after restrictions were eased. The networks of depression and anxiety symptoms in these individuals became denser — that is, the symptoms increasingly reinforced each other, forming a self-perpetuating system.

In people with low IU, levels of anxiety and depression remained stable throughout the observation period — even during the height of the pandemic.

Economic and behavioral aspects

Temporal ambivalence in decision making

Economists and behavioral scientists have long studied "uncertainty aversion" in the context of decision making. The classic concept of "risk aversion," introduced by John von Neumann and Oskar Morgenstern within the framework of expected utility theory, describes a preference for a smaller, but certain, outcome over a larger, but probabilistic one. However, research inspired by Daniel Ellsberg (1961) has shown that people don’t simply avoid risk — they especially avoid situations in which probabilities are completely uncertain. This phenomenon has become known as ambiguity aversion, or the Ellsberg paradox.

More recent studies clarify this picture. A study by Guo et al. (2025) found a statistically significant correlation between temporal ambiguity aversion and probabilistic ambiguity aversion (r = 0.28). People who react sensitively to time uncertainty are more likely to react sensitively to probability uncertainty — and vice versa.

Temporal ambivalence and delays of reward

A separate line of research examines behavior when choosing between immediate and delayed rewards under conditions where the timing of the latter is uncertain. A study by Ickink and colleagues (2024) showed that the impact of temporal uncertainty depends on the length of the delay and the magnitude of the reward. With short delays, timing uncertainty changes choice only slightly; with long ones, it significantly reduces the attractiveness of the delayed option. Simply put, the longer the delay and the less clear the exact timing, the more the future reward devalues in a person’s eyes.

Willingness to wait in uncertainty

A study by Tanovic and colleagues (2018) found that willingness to wait under uncertainty is associated with several individual variables. High impulsivity and poor emotion regulation skills reduce it, while higher uncertainty tolerance, conversely, increases it. Notably, overall anxiety levels were not an independent predictor of this behavior — what matters is how a person views uncertainty itself, not how anxious they are "in general."

Clinical manifestations

Intolerance of uncertainty in GAD

In generalized anxiety disorder, intolerance of uncertainty manifests itself in chronic worry about everything that has not yet been determined: health, work, relationships, finances. It’s not so much anxiety about a specific danger as a reaction to any "open question" in a person’s life. Worry is subjectively experienced as beneficial ("I think ahead, so I’ll be prepared"), although objectively it doesn’t reduce uncertainty or improve outcomes.

OCD and uncertainty reduction rituals

In obsessive-compulsive disorder, intolerance of uncertainty is often expressed through a compulsive need to check. A person realizes they’ve checked a door or a light switch, but doesn’t feel confident that everything is actually OK — that is, they suffer not from an objective threat, but from the inability to achieve subjective certainty. Compulsive rituals provide temporary relief but maintain a high IU, depriving the person of the opportunity to learn to tolerate uncertainty without immediately eliminating it.

Depression and being frozen in the unknown

The relationship between IU and depression has historically been less studied than its relationship with anxiety, but longitudinal data convincingly support it. People with high IU not only experience uncertainty more acutely but also have difficulty exiting anxious-depressive states: their symptom networks are more densely connected, meaning one symptom more easily triggers another. Fear as a symptom showed the strongest association with IU of all the components of anxious-depressive symptoms studied.

Stress, bodily reactions and physiology

Cortisol and sympathetic activation

Waiting in uncertainty triggers a physiological stress response, measurable both in laboratory settings and in field studies. Cortisol levels rise significantly more for threats with an unknown probability than for threats with a known probability, regardless of the objective severity of the threat. This suggests that the physiological stress system is tuned to respond to informational incompleteness, not just to actual danger.

Galvanic skin response (sweating palms), pupil dilation, and increased heart rate — all of these indicators in de Berker’s experiment correlated with the level of uncertainty, not the number of shocks received. The body reacts more strongly to "I don’t know" than to "I know it’s going to be bad."

Chronic anticipatory stress

When living in a state of uncertainty for a long time — which is typical, for example, for people with serious illnesses, whose loved ones are in critical condition, or for people experiencing long-term social instability — chronically elevated cortisol negatively impacts the immune system, cardiovascular system, and cognitive functions. Thus, uncertainty aversion is not only a psychological but also a physical problem.

Emotional consequences

Negative emotions in a situation of uncertainty

Research by Morris and colleagues has shown that uncertainty increases the intensity of fear, anxiety, sadness, and irritation. Moreover, people with high IU experience a wider range of emotions: uncertainty triggers not only anxiety but also anger and sadness — reactions that would seem less expected in a situation of simple ignorance.

This effect is explained by the Uncertainty Distress Model: uncertainty not only intensifies a specific emotion, but creates a broad affective “background” against which any emotional stimuli are perceived more acutely.

Suppression of positive emotions

The reverse effect is no less important: uncertainty reduces the intensity of positive emotions. Joy, excitement, and anticipation are all weaker in people in uncertain situations. The mechanism here is likely linked to competing cognitive resources: anxious threat monitoring "draws" attention away from positive stimuli.

In people with high intolerance of uncertainty, this effect is more pronounced: they not only experience less joy in situations of uncertainty, but they are practically incapable of fully experiencing positive emotions while some important question remains open.

Cultural and social dimensions

Hofstede’s Uncertainty Avoidance Index

At the cultural level, the phenomenon is described using the concept of Geert Hofstede, who in the 1970s and 1980s introduced the uncertainty avoidance index (UAI) as one of five basic dimensions of national cultures. Cultures with a high UAI — in particular, several Mediterranean countries, Japan, and Latin America — tend to create detailed rules and procedures that reduce uncertainty, while cultures with a low UAI — the Scandinavian countries, Singapore, and Jamaica — are more relaxed in open-ended situations.

It’s important to emphasize that cultural UAI is a statistical characteristic describing group-level trends, not a property of individual people. Within any culture, the distribution of individual UAI levels is broad.

Social structures as a response to uncertainty

Several researchers in political and social psychology have suggested that rigid social hierarchies, authoritarian regimes, and fundamentalist religious movements derive some of their support from a widespread aversion to uncertainty. Clear hierarchies, simple explanations, and clear rules reduce informational uncertainty — and are therefore psychologically attractive to people with high IU. This mechanism is described by Ari Kruglanski in his need for cognitive closure (NFCC) theory, which is conceptually similar to IU but describes a broader cognitive need for complete knowledge.

Therapeutic approaches

Cognitive behavioral therapy

IU-focused cognitive behavioral therapy (CBT), developed by Dugas and Robichaud, aims to directly address beliefs about uncertainty. Its key components are systematic exposure to situations of uncertainty (behavioral experiments) and reframing beliefs about uncertainty as dangerous and intolerable.

A fundamental difference from standard CBT is the focus not on the content of anxious thoughts, but on the attitude toward the unknown itself. The client learns not to "resolve" uncertainty (which is often impossible), but to maintain functioning in its presence. The effectiveness of this approach has been confirmed by a number of randomized controlled trials.

Acceptance and Commitment Therapy

Acceptance and Commitment Therapy (ACT) approaches uncertainty aversion from a different perspective. Rather than changing beliefs about uncertainty, ACT develops psychological flexibility — the ability to act in accordance with one’s values, even when thoughts and feelings associated with uncertainty are present and unpleasant.

Longitudinal studies during the pandemic have confirmed that psychological flexibility is one of the key buffers between high IU levels and symptoms of anxiety and depression.

Pharmacological correction

There are no direct pharmacological agents targeting IU specifically. However, medications that reduce general anxiety (SSRIs, anxiolytics) indirectly reduce the severity of the reaction to uncertainty. This further indicates that the neurobiological mechanisms of IU overlap with those of anxiety disorders, although they are not identical.

Applied contexts

Medicine and diagnostics

The medical context is one of the most illustrative examples of how uncertainty aversion works in everyday life. Waiting for biopsy results, genetic tests, and cancer screenings generates acute anxiety, often comparable in intensity to the reaction to the bad news itself — and sometimes even greater.

This has direct practical implications. Telling the patient a precise timeframe for receiving results — even if it’s a long one — significantly reduces anxiety during the waiting period compared to not knowing how long to wait. Knowing the time horizon provides the brain with structure and reduces the burden on the threat monitoring system.

Labor relations and organizational environment

In the corporate context, periods of organizational change — mergers, restructurings, layoffs — are classic generators of mass uncertainty. Research in organizational psychology shows that the period of uncertainty surrounding layoffs causes greater psychological harm to employees than the news of layoffs themselves. The announcement that "nothing will change" and the announcement that "you’ll be fired in a month" both reduce anxiety more than the expectation of "maybe you’ll be fired, maybe not."

Justice and imprisonment

A study of the psychological effects of indeterminate sentences — sentences without a fixed release date, or indefinite pretrial detention — has documented consistent differences in anxiety and depression compared to prisoners with a known release date. Uncertainty of release correlates with more severe mental health consequences than a long but known sentence.

Economic decisions under risk

In behavioral economics, ambiguity aversion influences financial decisions: investment behavior, insurance, and the choice of retirement plans. People with high ambiguity aversion systematically overpay for certainty — they choose a lower but certain income, even when the expected value of the uncertain option is higher. This isn’t irrationality in the conventional sense, but a reflection of the real psychological cost of uncertainty for a given person.

The adaptive side of uncertainty aversion

Stress as a risk signal

De Berker’s experiment revealed an unexpected adaptive aspect: participants whose physiological stress more accurately tracked the level of uncertainty demonstrated higher threat prediction accuracy. That is, the stress response to uncertainty functioned as an adaptive risk sensor, not just a source of distress.

This is consistent with the evolutionary view: under real threat, heightened vigilance during uncertainty provided a survival advantage. The problem arises when this same system is activated in situations that pose no objective threat — when awaiting a letter, the outcome of a job interview, or a response to a message.

Moderate uncertainty and motivation

Moderate uncertainty of a positive outcome has a strong motivational potential. This is why games, creative challenges, and scientific research are so captivating: the probability of success is neither zero nor one. Complete predictability of the outcome reduces motivation — the brain is disinterested in doing something it already "knows" the outcome.

This same mechanism explains why some people deliberately choose risky activities or professions with high uncertainty — and derive pleasure from them. The individual threshold at which uncertainty becomes a stressor rather than a motivator varies considerably.

Measurement and diagnostics

Scales and instruments

A number of psychometric instruments have been developed to measure intolerance of uncertainty. The most widely used are:

• The Intolerance of Uncertainty Scale (IUS-27 and its shortened version IUS-12) assesses two factors: prospective concern and inhibitory response to uncertainty.
• The Norton Ambiguity Tolerance Scale (AT-20) measures positive willingness to work under ambiguity.
• Kruglanski’s Need for Cognitive Closure Scale (NFCS) is broader in scope, but overlaps with IU in terms of its desire for certainty.

These scales are not interchangeable: they measure overlapping but distinct constructs. The IUS focuses specifically on discomfort with uncertainty, while the NFCS focuses on the need for complete knowledge per se.

Transdiagnostic status

The transdiagnostic nature of IU deserves special attention. Unlike specific symptoms — obsessions in OCD or social anxiety in social phobia — intolerance of uncertainty is found in virtually all anxiety and affective disorders. This makes it a promising target for therapeutic interventions: reducing IU potentially improves symptoms across multiple diagnostic axes.