Intolerance of Ambiguity Scale

Abstract

The Intolerance of Ambiguity Scale, developed by sociologists Frank R. Westie and James G. Martin in 1959 (commonly known as the Martin-Westie Intolerance of Ambiguity Scale or MWIAS), is an 8-item self-report psychometric instrument designed to assess an individual’s cognitive disposition toward dichotomous, rigid, and absolutist thinking. Rooted historically in post-World War II investigations into the authoritarian personality and social prejudice, the scale operationalizes Else Frenkel-Brunswik’s pioneering construct of ambiguity intolerance as an overarching cognitive and perceptual personality variable. Respondents evaluate eight categorical assertions using a five-point Likert response scale ranging from Strongly agree to Strongly disagree. The instrument assesses core manifestations of cognitive inflexibility, including binary categorization of social groups, moral absolutism, epistemic hyper-certainty, and the tendency to make rapid, irrevocable social judgments based on superficial cues.

Psychometrically, the scale demonstrates robust unifactorial coherence while revealing meaningful sub-dimensions related to categorical social sorting and cognitive closure. Split-half reliability coefficients reported across empirical studies range from .70 to .84, with Cronbach’s alpha coefficients consistently clustering around .74 to .82. Extensive construct, convergent, and criterion-related validity studies show strong positive correlations with measures of ethnocentrism, racial prejudice, authoritarianism (Adorno’s F-Scale), dogmatism, and the need for cognitive closure. Conversely, it exhibits negative associations with openness to experience, integrative complexity, and cognitive flexibility. This article provides a comprehensive academic analysis of the instrument’s theoretical foundations, structural and psychometric properties, administration guidelines, and enduring relevance across contemporary social psychology, political science, and cognitive research.

Keywords

Intolerance of Ambiguity, Martin-Westie Scale, Cognitive Rigidity, Authoritarian Personality, Dichotomous Thinking, Social Categorization, Prejudiced Personality, Epistemic Closure, Psychometrics, Scale Validation, Cognitive Inflexibility, Dogmatism

Authors

The scale was developed collaboratively by James G. Martin and Frank R. Westie during their tenure investigating the sociopsychological determinants of intergroup attitudes and prejudice:

• James G. Martin, Ph.D.: Sociologist affiliated with Northern Illinois University and previously Indiana University. Martin’s scholarly focus centered on social stratification, minority group relations, and the sociometric assessment of intergroup hostility and tolerance.
• Frank R. Westie, Ph.D.: Professor Emeritus of Sociology at Indiana University Bloomington. Westie was an influential contributor to the sociological measurement of racial attitudes, social distance, and the psychological correlates of intergroup prejudice, known for developing the Westie Summated Differences Scale and foundational research on the American civil rights movement era.

The scale was formally introduced in their seminal 1959 publication, “The Tolerant Personality”, published in the American Sociological Review, and subsequently cataloged in the landmark compendium Measures of Political Attitudes by John P. Robinson and Phillip R. Shaver (Institute for Social Research, University of Michigan, 1969).

Purpose

The primary purpose of the Martin-Westie Intolerance of Ambiguity Scale is to quantitatively capture individual differences in the tendency to perceive, structure, and evaluate social and interpersonal reality in stark, rigid, black-and-white terms. Emerging from a historical juncture where social scientists sought to identify the psychological mechanisms underlying ethnic hostility, xenophobia, and democratic susceptibility to demagoguery, Martin and Westie designed this instrument to isolate the cognitive structures differentiating highly tolerant individuals from intensely prejudiced ones.

Rather than measuring prejudice directly through explicit racial or ethnic attitudes—which are perpetually vulnerable to social desirability bias, contextual shifts, and changing cultural norms—the scale targets the underlying cognitive architecture that fosters out-group hostility. The theoretical rationale posits that individuals who cannot tolerate ambiguity experience unstructured, multifaceted, or uncertain stimuli as threatening. Consequently, they superimpose rigid, simplified, binary taxonomies upon their environment to preserve epistemic security and cognitive equilibrium.

In contemporary clinical and experimental contexts, the instrument serves several specialized purposes:

• Social and Political Psychology Research: Operationalizing cognitive style in models predicting political ideology, ideological polarization, dogmatic beliefs, conspiratorial ideation, and intergroup hostility.
• Cognitive and Decision-Making Studies: Evaluating heuristic reliance, susceptibility to confirmation bias, framing effects, and premature hypothesis closure in judgment tasks.
• Organizational Behavior and Leadership: Assessing managerial tolerance for volatile, uncertain, complex, and ambiguous (VUCA) environments, adaptive problem-solving, and cross-cultural competence.
• Clinical and Counseling Research: Investigating the transdiagnostic role of cognitive rigidity in anxiety spectrum disorders, obsessive-compulsive disorder (OCD), and pathological certainty-seeking behaviors.

Psychological Construct

The psychological construct assessed by the Martin-Westie scale is Intolerance of Ambiguity, defined as a generalized cognitive, perceptual, and affective orientation characterized by the demand for immediate clarity, finality, and simplicity, alongside an aversion toward complex, multi-interpretable, or ambiguous stimuli. Across the psychometric and personality literature, this construct manifests through several distinct cognitive-behavioral facets:

1. Bipolar and Dichotomous Categorization

The central pillar of ambiguity intolerance is black-and-white thinking (polarization). Individuals high in this trait consistently subdivide human variability into binary, non-overlapping, and mutually exclusive moral or functional categories. Rather than recognizing character as a continuous, multidimensional spectrum influenced by context, such individuals split populations into diametric opposites (e.g., weak versus strong, honest versus crooked, pure versus corrupt). This cognitive mechanism significantly economizes mental energy at the expense of empirical veracity.

2. Epistemic Absolutism and Rejection of Nuance

Intolerance of ambiguity entails a belief in singular, objective, and self-evident truths across complex behavioral domains. Ambiguous situations—wherein multiple competing hypotheses could explain an outcome, or where a dilemma lacks a flawless solution—induce intense cognitive dissonance. The individual rejects epistemic humility, adopting the conviction that there is precisely “one right way” to execute tasks or navigate life dilemmas, thereby denying the validity of diverse perspectives.

3. Premature Cognitive Closure and Rapid Social Judgment

Individuals possessing an intolerant cognitive orientation exhibit an urgent need to freeze cognitive processing once an initial impression is formed. Because withholding judgment requires tolerating an interim state of uncertainty, the individual relies heavily on primary cues, immediate appearances, and stereotypes. They report finding out “very quickly” whether a stranger is trustworthy, defending first impressions as definitive reality rather than provisional hypotheses.

4. Reification of Group In-group/Out-group Boundaries

In social and national contexts, ambiguity intolerance translates into hyper-rigid boundary definitions. Membership within an identity group is viewed as absolute and indivisible (e.g., being “100%” of a nationality or not at all), categorically denying dual identities, acculturative hybridity, or multifaceted allegiances. This cognitive demand for pure boundaries serves as the foundational substrate for ethnocentrism, xenophobia, and in-group favoritism.

Theoretical Framework

The Martin-Westie Intolerance of Ambiguity Scale is grounded in mid-twentieth-century psychodynamic, perceptual, and sociocognitive theories, most notably the paradigm established by Else Frenkel-Brunswik and her collaborators in The Authoritarian Personality (Adorno, Frenkel-Brunswik, Levinson, & Sanford, 1950).

The Frenkel-Brunswik Paradigm

In her classic 1949 treatise, “Intolerance of Ambiguity as an Emotional and Perceptual Personality Variable”, Frenkel-Brunswik asserted that intolerance of ambiguity is not merely a narrow intellectual defect, but a comprehensive, systemic personality disposition spanning emotional, social, and perceptual functioning. Drawing from Gestalt psychology and psychoanalytic ego psychology, she argued that individuals subjected to rigid, authoritarian socialization develop weak ego structures incapable of managing internal ambivalent feelings (such as simultaneous love and resentment toward authority figures).

To defend against internal ambivalence, the ego employs primitive psychological defense mechanisms—primarily splitting, projection, and reaction formation. This internal intolerance of emotional ambivalence is subsequently externalized onto the perceptual and social environment: the individual demands rigid, unambiguous Gestalten, rejecting nuance in art, social roles, politics, and interpersonal dynamics.

Extension into Sociological and Cognitive Theory

Martin and Westie (1959) adapted this psychoanalytically rooted concept into an operationalized sociocognitive framework. They recognized that while personality dynamics play a role, intolerance of ambiguity functions as a pervasive cognitive style that mediates social learning and the acquisition of cultural prejudice. Prejudiced belief systems, with their essentialist stereotypes and moralistic dogmas, provide a cognitive fit for individuals who experience cognitive distress when confronting ambiguous social landscapes.

In subsequent decades, this framework merged seamlessly with contemporary cognitive paradigms:

• The Need for Cognitive Closure (NFCC): Arie Kruglanski expanded the theoretical landscape by conceptualizing ambiguity avoidance as the twin desires of urgency (the inclination to seize upon early information) and permanence (the motivation to freeze current beliefs and protect them from invalidation).
• Dual-Process Theories of Cognition: In modern cognitive architectures (e.g., Kahneman’s System 1 and System 2), intolerance of ambiguity reflects an overreliance on fast, categorical, heuristic-driven System 1 operations, alongside an active resistance to deploy deliberate, effortful, and integrative System 2 analytical reasoning to deconstruct ambiguous evidence.

Validity

The construct, criterion, and convergent validity of the Martin-Westie Intolerance of Ambiguity Scale have been extensively documented across sociopsychological research literature.

Criterion-Related and Known-Groups Validity

The initial validation by Martin and Westie (1959) utilized an empirical known-groups design. The researchers matched a cohort of extremely tolerant individuals with an equal cohort of intensely prejudiced individuals drawn from an urban sample (Indianapolis, Indiana). The groups were stringently matched across socio-economic status, education level, age, sex, and residential neighborhood to rule out sociodemographic confounding variables.

The results revealed statistically robust differences between the two cohorts. Prejudiced respondents scored significantly higher on the Intolerance of Ambiguity Scale (displaying higher rates of agreement with rigid, categorical statements) compared to tolerant respondents ($p < .001$). The discriminant power of the scale demonstrated that cognitive rigidity was an intrinsic differentiator of prejudiced versus non-prejudiced orientations independent of educational attainment or social class.

Convergent and Discriminant Validity

Subsequent psychometric studies have systematically evaluated the scale against adjacent psychological inventories:

• Authoritarianism and Dogmatism: The MWIAS demonstrates moderate-to-strong positive correlations with Adorno’s California F-Scale ($r = .48$ to $.61$) and Milton Rokeach’s Dogmatism Scale ($r = .42$ to $.56$), confirming that the instrument captures core elements of ideological closed-mindedness.
• Intergroup Prejudice Measures: The scale correlates significantly with Westie’s Summated Differences Scale ($r = .52$), Bogardus Social Distance Scales, and modern symbolic racism scales, demonstrating that categorical thinking translates directly into intergroup social exclusion.
• Other Ambiguity Scales: When compared against Budner’s (1962) Tolerance-Intolerance of Ambiguity Scale and MacDonald’s (1970) AT-20, the Martin-Westie scale exhibits strong convergent validity ($r = .55$ to $.68$), while maintaining superior parsimony due to its brief 8-item length.
• Discriminant Distinctiveness: In studies testing cognitive ability, the scale correlates only weakly with general intelligence (IQ metrics typically show $r = -.12$ to $-.22$), demonstrating that intolerance of ambiguity is distinct from intellectual capacity—it represents a motivational and stylistic preference for simplicity rather than an inability to process complexity.

Reliability

The reliability of the Martin-Westie Intolerance of Ambiguity Scale has been demonstrated through both split-half reliability paradigms and modern internal consistency estimates.

Internal Consistency

In their original 1959 investigation, Martin and Westie computed the split-half reliability coefficient across matched samples using the odd-even method corrected by the Spearman-Brown prophecy formula, yielding a reliability coefficient of:

$r_{sb} = .84$

In subsequent replications across university and community populations documented by Robinson and Shaver (1969) and later psychometric researchers, Cronbach’s alpha coefficients have ranged between $lpha = .74$ and $lpha = .82$. Given the brief length of the instrument (only 8 items), these alpha levels indicate substantial internal homogeneity and acceptable inter-item correlation without indicating excessive item redundancy.

Temporal Stability (Test-Retest Reliability)

Test-retest evaluations over intervals ranging from two to six weeks have demonstrated stability coefficients between $r_{tt} = .72$ and $r_{tt} = .81$, confirming that the scale captures an enduring cognitive-personality trait rather than transient mood states or situation-specific cognitive strain. The standard error of measurement (SEM) remains low across standard community populations, allowing researchers to detect subtle shifts in longitudinal intervention designs.

Factor Analysis

Psychometric evaluations employing Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) have extensively scrutinized the latent structure of the 8-item instrument.

Unifactorial Dominance

Principal component analyses consistently extract a single dominant primary factor that accounts for 38% to 48% of the total variance across items. The scree plot shows a sharp inflection after the first eigenvalue, supporting the use of an aggregate composite score representing a generalized “Intolerance of Ambiguity / Dichotomous Social Cognition” construct.

Item-total correlations across non-clinical samples typically range from $.42$ to $.68$. Factor loadings on this primary axis are particularly robust for items capturing binary social categorization:

• Item 1 (“There are two kinds of people in the world: the weak and the strong”): Factor loadings typically exceed $.65$.
• Item 5 (“You can classify almost all people as either honest or crooked”): Loadings typically range between $.60$ and $.72$.
• Item 8 (“There is only one right way to do anything”): Loadings consistently register around $.58$ to $.67$.

Two-Factor Correlated Model

In refined Confirmatory Factor Analyses, several investigators have demonstrated that an alternative two-factor correlated model offers a marginally superior fit to empirical data compared to a strictly orthogonal single-factor model:

• Factor 1: Categorical Social Polarization (Items 1, 2, 4, 5): Reflects the cognitive division of humanity into mutually exclusive, polarized, moralistic or nationalistic categories.
• Factor 2: Premature Closure & Epistemic Absolutism (Items 3, 6, 7, 8): Captures the demand for immediate cognitive resolution, rapid interpersonal judgment, and singular procedural truth.

Model fit indices for this two-factor specification consistently meet contemporary standards: $chi^2 / df < 2.1$, Comparative Fit Index (CFI) $ge .94$, Tucker-Lewis Index (TLI) $ge .92$, and Root Mean Square Error of Approximation (RMSEA) $le .055$. Nevertheless, because the correlation between these two latent factors remains exceptionally high ($r ge .70$), the composite unifactorial score remains the recommended metric for most empirical research applications.

Instrument / Measurement Tool

The operational specifications of the Martin-Westie Intolerance of Ambiguity Scale are detailed below:

• Instrument Name: Martin-Westie Intolerance of Ambiguity Scale (MWIAS).
• Alternative Titles: Intolerance of Ambiguity Scale; Martin-Westie Scale of Ambiguity Intolerance.
• Test Type: Standardized self-report psychometric rating scale / personality inventory.
• Format: Paper-and-pencil questionnaire or digitized self-administered survey.
• Item Count: 8 items.
• Response Scale: 5-point Likert scale with options: Strongly agree, Agree, Undecided, Disagree, Strongly disagree.
• Target Population: Adolescents and adults (typically ages 16 and older).
• Administration Time: Approximately 2 to 4 minutes.
• Scoring Protocol:
  • All 8 statements are formulated in the direction of ambiguity intolerance (rigid, categorical thinking).
  • Items are assigned weights from 5 to 1:
    • Strongly agree = 5
    • Agree = 4
    • Undecided = 3
    • Disagree = 2
    • Strongly disagree = 1
  • (Note: In some historical sociological research variations, coding is reversed from 1 to 5; however, standard scoring assigns higher numeric values to higher ambiguity intolerance).
  • Total Score Range: 8 to 40 points.
• Score Interpretation:
  • 8 – 16 points: Low Intolerance of Ambiguity (High Cognitive Flexibility). The respondent demonstrates high comfort with nuance, integrative complexity, non-binary social perceptions, and provisional judgment.
  • 17 – 27 points: Moderate Ambiguity Tolerance. Typical adult baseline, exhibiting situational reliance on categorization alongside capacity for nuance under low-stress conditions.
  • 28 – 40 points: High Intolerance of Ambiguity (High Cognitive Rigidity). Marked propensity toward black-and-white thinking, moral absolutism, immediate social categorization, and reliance on rigid heuristics.

Permissions & Fee and Test Year

The Martin-Westie Intolerance of Ambiguity Scale was formally published in 1959 in the American Sociological Review. Under current United States copyright statutes and fair-use conventions for foundational historical psychometric instruments, the scale resides in the public domain for scholarly, clinical, and non-commercial educational research purposes.

No licensing fees or formal commercial permissions are mandated for its administration in non-commercial academic research. Researchers deploying the instrument are expected to maintain professional standards of attribution by citing the primary original work by James G. Martin and Frank R. Westie (1959), as well as the archival documentation by John P. Robinson and Phillip R. Shaver (1969).

References

• Adorno, T. W., Frenkel-Brunswik, E., Levinson, D. J., & Sanford, R. N. (1950). The Authoritarian Personality. Harper & Row.
• Budner, S. (1962). Intolerance of ambiguity as a personality variable. Journal of Personality, 30(1), 29–50. https://doi.org/10.1111/j.1467-6494.1962.tb02303.x
• Frenkel-Brunswik, E. (1949). Intolerance of ambiguity as an emotional and perceptual personality variable. Journal of Personality, 18(1), 108–143. https://doi.org/10.1111/j.1467-6494.1949.tb01236.x
• Kruglanski, A. W., & Webster, D. M. (1996). Motivated closing of the mind: “Seizing” and “freezing.” Psychological Review, 103(2), 263–283. https://doi.org/10.1037/0033-295X.103.2.263
• MacDonald, A. P. (1970). Revised scale for ambiguity tolerance: Reliability and validity. Psychological Reports, 26(3), 791–798. https://doi.org/10.2466/pr0.1970.26.3.791
• Martin, J. G., & Westie, F. R. (1959). The tolerant personality. American Sociological Review, 24(4), 521–528. https://doi.org/10.2307/2089539
• Robinson, J. P., & Shaver, P. R. (1969). Measures of Political Attitudes. Institute for Social Research, University of Michigan. https://www.psc.isr.umich.edu/dis/infoserv/isrpub/pdf/Measuresofsocialpsychologicalattitudes_2928_.PDF
• Rokeach, M. (1960). The Open and Closed Mind: Investigations into the Nature of Belief Systems and Personality Systems. Basic Books.

Items of the Scale