Interaction Anxiousness Scale

1. Abstract

The Interaction Anxiousness Scale (IAS) is a widely utilized, 15-item self-report psychometric instrument developed by Mark R. Leary in 1983 to assess the affective, subjective dimension of social anxiety that emerges specifically within contingent interpersonal interactions. Unlike omnibus measures that blend subjective anxiety with behavioral avoidance, overt social skills deficits, or public performance anxiety, the IAS was intentionally engineered to isolate the pure subjective feeling of tension, apprehension, and nervousness experienced in interpersonal exchanges. The instrument addresses social situations where an individual’s behavioral output is contingent upon the communicative responses of others—such as casual get-togethers, encounters with authority figures, parties, dates, and telephonic interactions.

Respondents rate each of the 15 items on a 5-point Likert-type response scale ranging from 1 (Not at all characteristic of me) to 5 (Extremely characteristic of me). Five items are keyed in the reverse direction to counteract response bias and acquiescence. The IAS yields a continuous, unidimensional total score ranging from 15 to 75, with higher scores reflecting elevated levels of dispositional interaction anxiety. Extensive empirical evaluations across clinical, college, and community samples have affirmed the scale’s robust psychometric foundation, demonstrating high internal consistency (Cronbach’s alpha values regularly exceeding .87 to .91), impressive temporal stability (test-retest correlations ranging from .79 to .82 across intervals up to eight weeks), and a stable, replicable unifactorial structure confirmed through both exploratory and confirmatory factor analyses. The instrument exhibits strong convergent validity with constructs such as social phobia, fear of negative evaluation, and communication apprehension, while maintaining distinct discriminant validity against somatic complaints, depression, and general neurotic distress.

2. Keywords

Interaction Anxiousness Scale, social anxiety, Mark R. Leary, social interaction, psychometrics, self-presentation theory, shyness, test reliability, construct validity, social phobia

3. Authors

The Interaction Anxiousness Scale was conceptualized, constructed, and psychometrically validated by Mark R. Leary, Ph.D., an eminent social and personality psychologist. Dr. Leary completed his foundational psychometric work on the instrument while affiliated with the Department of Psychology at Denison University and the University of Texas at Austin, subsequently expanding and refining the validation literature at Wake Forest University and Duke University, where he served as Garonzik Family Professor Emeritus of Psychology and Neuroscience.

Subsequent psychometric investigations, criterion validations, and cross-cultural extensions were conducted in collaboration with Robin M. Kowalski, Ph.D., Professor of Psychology at Clemson University. Researchers seeking operational guidance or permissions can consult Dr. Leary’s academic repositories or contact Duke University’s Department of Psychology and Neuroscience.

4. Purpose

The primary clinical and empirical purpose of the Interaction Anxiousness Scale (IAS) is to provide a pure, unconfounded assessment of the subjective affective experience of social anxiousness during contingent interpersonal interactions. During the 1970s and early 1980s, assessment instruments in social psychology and clinical psychiatry—such as the Social Avoidance and Distress (SAD) Scale and the Fear of Negative Evaluation (FNE) Scale—frequently merged subjective anxiety, cognitive evaluation, and overt behavioral avoidance into combined summary scores. Leary recognized that measuring behavioral avoidance as a proxy for subjective emotional anxiety introduced severe construct contamination: individuals might avoid social settings due to low sociability, introversion, depressive anhedonia, or practical constraints, rather than autonomic arousal or experienced social fear. Conversely, socially anxious individuals often force themselves into required interpersonal settings despite enduring severe inner affective torment.

To rectify this operational confounding, the IAS was intentionally designed to fulfill three foundational objectives:

• Isolating Affective Anxiousness: The scale measures subjective nervousness, apprehension, and tension without conflating these states with overt motor actions, behavioral inhibition, or physiological symptomatology.
• Targeting Contingent Social Interactions: The IAS distinguishes between public performance anxiety (e.g., public speaking, musical performance, stage acting) and contingent interpersonal interactions (e.g., informal conversations, initiating telephone calls, speaking to authority figures, meeting unfamiliar peers). In contingent interactions, behavioral responses cannot be pre-scripted, significantly increasing vulnerability to self-presentational failure.
• Facilitating Dual Research and Clinical Diagnoses: In laboratory experiments, the scale serves as a sensitive moderator variable in social-evaluative contexts, whereas in clinical psychology and psychiatry, it aids in diagnosing Social Anxiety Disorder (SAD), evaluating cognitive-behavioral therapy (CBT) outcomes, and tailoring social skills interventions.

5. Psychological Construct

The psychological construct captured by the IAS is social interaction anxiousness—defined as a stable disposition or tendency to experience subjective anxiety, apprehension, and distress in social situations where an individual must interact with others. The scale operationalizes this construct across multiple interpersonal contexts while maintaining a single, unified affective core:

Contingent dyadic and group interactions

The core dimension of the construct relates to unstructured, dynamic interpersonal communication. Unlike audience-based situations, dyadic and small-group conversations demand continuous social monitoring, turn-taking, mentalizing, and real-time behavioral adjustments. Items such as Item 1 (“I often feel nervous even in casual get-togethers“) and Item 5 (“Parties often make me feel anxious and uncomfortable“) capture the emotional friction elicited when individuals must navigate spontaneous, informal social environments.

Interactions Across Hierarchical and Evaluative Gradients

Social anxiety escalates sharply when power asymmetries or critical evaluations are salient. Individuals with elevated interaction anxiousness perceive encounters with high-status individuals as high-risk interactions where negative evaluation carries material or reputational consequences. This facet is operationalized by Item 4 (“I get nervous when I must talk to a teacher or a boss“) and Item 14 (“I get nervous when I speak to someone in a position of authority“).

Initiating Encounters and Novel Social Networks

The anxiety associated with social novelty—meeting unfamiliar individuals or breaching psychological boundaries—is an essential facet of interaction anxiousness. Approaching strangers exposes individuals to acute uncertainty regarding acceptance versus social ostracism. Items measuring this facet include Item 2 (“I usually feel comfortable when I’m in a group of people I don’t know“) and Item 13 (“I often feel nervous when calling someone I don’t know very well on the telephone“).

Affiliative and Romantic Dyadic Encounters

Interactions that involve romantic interest, sexual attraction, or opposite-sex peer evaluation present potent self-presentational demands. In these exchanges, individuals place high value on projecting desirable physical, intellectual, or interpersonal attributes. The IAS assesses this vulnerability through Item 3 (“I am usually at ease when speaking to a member of the other sex“) and Item 12 (“I often feel nervous when talking to an attractive member of the opposite sex“).

6. Theoretical Framework

The Interaction Anxiousness Scale is rooted in Self-Presentation Theory (also known as Impression Management Theory), developed comprehensively by Mark R. Leary and Barry R. Schlenker. According to self-presentation theory, social anxiety is not an irrational or arbitrary emotional eruption, but rather an adaptive warning signal triggered under specific cognitive and motivational conditions.

Specifically, Leary and Kowalski (1990) formalized the self-presentational model of social anxiety around a fundamental propositional formula:

Social anxiety arises when an individual is motivated to make a particular impression on real or imagined audiences, but doubts their ability to successfully convey that desired impression.

The theoretical framework involves two core interacting components:

1. Impression Motivation: The degree to which an individual desires to control how they are perceived by others. When relational outcomes (e.g., social inclusion, romantic bonding, occupational promotion, status preservation) depend directly on audience appraisal, impression motivation is high.
2. Impression Efficacy: The subjective probability or confidence an individual holds that they can successfully project the desired identity and secure favorable evaluation. If an individual doubts their conversational competence, physical appeal, social status, or emotional composure, impression efficacy falls.

When high impression motivation is paired with low impression efficacy, subjective social anxiousness inevitably manifests. In contingent social interactions, maintaining high impression efficacy is difficult because conversations are inherently unpredictable; one cannot anticipate all questions, interruptions, subtle nonverbal cues, or conversational silences. Consequently, individuals with high dispositional interaction anxiousness experience persistent, anticipatory distress regarding the prospect of social blunders, awkward pauses, or negative interpersonal appraisal.

7. Validity

The psychometric validity of the Interaction Anxiousness Scale has been confirmed across dozens of empirical investigations involving college student cohorts, general community samples, and clinical populations diagnosed with anxiety disorders.

Construct and Convergent Validity

The IAS demonstrates robust convergent validity with theoretical constructs belonging to the broader nomological network of social distress. Leary (1983) and Leary and Kowalski (1993) reported significant, positive correlations between the IAS and established measures of social evaluative fear, including:

• Brief Fear of Negative Evaluation (BFNE) Scale: Pearson correlations ranging between r = .55 and .68, demonstrating shared variance with the cognitive fear of negative judgment.
• Social Avoidance and Distress (SAD) Scale: Significant correlations between r = .67 and .73 with the distress subscale of the SAD.
• Social Interaction Anxiety Scale (SIAS): Cross-validation studies indicate high convergence (r = .70 to .82) with Mattick and Clarke’s SIAS.
• Shyness Measures: Correlations exceeding r = .70 with the Cheek and Buss Shyness Scale, affirming that dispositional shyness and interaction anxiousness share an overlapping affective core.

Discriminant and Divergent Validity

To establish that the IAS does not merely measure non-specific negative affectivity, general psychological maladjustment, or broad neuroticism, discriminant validity was evaluated:

• Public Performance Anxiety: Correlations between the IAS and performance-oriented measures (such as the Personal Report of Communication Apprehension or public speaking fear inventories) are moderate (typically r = .35 to .45), confirming that social interaction anxiety is psychometrically distinct from the fear of formal public speaking.
• Depression and General Neuroticism: While modestly related to the Beck Depression Inventory (BDI; r = .25 to .35) and the Eysenck Neuroticism scale (r = .38 to .46), the magnitude of these associations demonstrates that interaction anxiousness cannot be reduced to general neurotic dysphoria.
• Somatic Symptom Measures: Unlike scales that record tachycardia, diaphoresis, or tremor, the IAS correlates only moderately with pure somatic symptom inventories (r < .30), confirming its focus on subjective cognitive-affective distress.

Criterion-Related and Behavioral Validity

Laboratory experiments have shown that the IAS predicts behavioral and physiological responses in actual social interactions. In experimental paradigms involving unstructured dyadic interactions with strangers, high-IAS scorers exhibited significantly more self-reported subjective tension, initiated fewer conversational turns, displayed shorter durations of eye contact, and demonstrated higher behavioral hesitations compared to low-IAS scorers (Leary, 1983; Leary & Kowalski, 1993).

8. Reliability

The Interaction Anxiousness Scale exhibits strong internal consistency and temporal stability across diverse populations and cultural adaptations.

Internal Consistency

In the original scale development study, Leary (1983) administered the IAS to multiple independent samples of undergraduate participants, yielding Cronbach’s alpha coefficients of .88, .89, and .89. Subsequent validation research by Leary and Kowalski (1993) reported internal consistency estimates ranging between α = .87 and α = .91 in college and community cohorts. Corrected item-total correlations across the 15 items consistently range between .45 and .73, with no individual item deletion yielding an increase in the composite coefficient alpha, confirming that every item contributes meaningfully to the common construct.

Test-Retest Stability

The temporal stability of the IAS supports its conceptualization as a dispositional, trait-like construct:

• Four-Week Interval: Leary (1983) reported an eight-week test-retest correlation coefficient of r = .82 (p < .001).
• Six-Week Interval: Studies evaluating untreated control groups in clinical intervention studies found stability coefficients of r = .80.
• Eight-Week Interval: Leary and Kowalski (1993) demonstrated stability coefficients ranging from r = .79 to .83, indicating that individual differences in interaction anxiousness remain stable over time in the absence of targeted cognitive-behavioral interventions.

9. Factor Analysis

The structural dimensionality of the Interaction Anxiousness Scale has been examined using both Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA).

Exploratory Factor Analysis (EFA)

In Leary’s (1983) foundational principal components and common factor analyses, the unrotated factor matrix revealed a dominant first factor accounting for approximately 38% to 44% of the total variance, with an eigenvalue exceeding 5.7. A scree plot inspection clearly indicated an “elbow” after the first primary eigenvalue, with the secondary eigenvalue falling precipitously below 1.3. While some early exploratory analyses noted slight clustering of the five reverse-scored items—a well-documented artifact of item directionality—all 15 items demonstrated primary factor loadings on the general interaction anxiousness factor exceeding .40, with the vast majority loading between .52 and .78.

Confirmatory Factor Analysis (CFA)

Subsequent psychometric investigations utilizing CFA have assessed whether the unidimensional model provides adequate empirical fit. Structural equation modeling has tested both a single-factor model and a two-factor model distinguishing between direct-worded items and reverse-worded items. The single-factor model incorporating a method effect (correlated error terms among reverse-scored items) consistently achieves strong goodness-of-fit indices across published studies:

These findings substantiate that the Interaction Anxiousness Scale functions as an essentially unidimensional scale suitable for generating a single total score reflecting trait interaction anxiousness.

10. Instrument / Measurement Tool

The Interaction Anxiousness Scale is a self-administered psychometric questionnaire. Below are its primary administration, scoring, and structural parameters:

• Instrument Type: Self-report psychological questionnaire.
• Primary Target Construct: Subjective affective anxiousness in contingent social interactions.
• Item Count: 15 items.
• Administration Time: Approximately 3 to 5 minutes.
• Response Scale: 5-point Likert-type scale:
  • 1 = Not at all characteristic of me
  • 2 = Slightly characteristic of me
  • 3 = Moderately characteristic of me
  • 4 = Very characteristic of me
  • 5 = Extremely characteristic of me
• Reverse-Scored Items: Items 2, 3, 6, 10, and 15 are phrased positively (reflecting social comfort or low shyness) and must be reverse-scored prior to calculating the total score (i.e., 1 becomes 5, 2 becomes 4, 3 remains 3, 4 becomes 2, and 5 becomes 1).
• Scoring Procedure:
  1. Invert the numerical values of the five reverse-scored items: (6 – Original Score) for Items 2, 3, 6, 10, and 15.
  2. Sum the values across all 15 items.
  3. Theoretical total score ranges from 15 (minimal interaction anxiousness) to 75 (maximum interaction anxiousness).
• Normative Reference Values: In general college populations, mean total scores hover around 38.0 to 41.0 (SD ≈ 9.0 to 10.5). Scores above 48 to 50 generally correspond to one standard deviation above the collegiate mean, frequently indicating clinically meaningful levels of social distress that warrant further screening for Social Anxiety Disorder.

11. Permissions & Fee and Test Year

The Interaction Anxiousness Scale was formally published in 1983 by Dr. Mark R. Leary in the Journal of Personality Assessment. In keeping with standard academic dissemination practices, the scale was placed into the public domain for non-commercial educational, scientific, and empirical research purposes.

Researchers, educators, and clinicians are permitted to administer, reproduce, and utilize the IAS without paying royalty or licensing fees, provided that appropriate academic attribution is accorded to Mark R. Leary. The instrument and its administrative scoring guidelines are documented in Dr. Leary’s academic repository hosted via Duke University. Commercial vendors, software publishers, or organizational entities intending to incorporate the scale into fee-generating products should request written permission from the original copyright holder or the publisher (Taylor & Francis / Routledge).

12. References

• Leary, M. R. (1983). Social anxiousness: The construct and its measurement. Journal of Personality Assessment, 47(1), 66–75. https://doi.org/10.1207/s15327752jpa4701_8
• Leary, M. R., & Kowalski, R. M. (1990). Impression management: A literature review and two-component model. Psychological Bulletin, 107(1), 34–47. https://doi.org/10.1037/0033-2909.107.1.34
• Leary, M. R., & Kowalski, R. M. (1993). The Interaction Anxiousness Scale: Construct and criterion-related validity. Journal of Personality Assessment, 61(1), 136–146. https://doi.org/10.1207/s15327752jpa6101_10
• Leary, M. R., & Kowalski, R. M. (1995). Social anxiety. Guilford Press. https://www.guilford.com/books/Social-Anxiety/Leary-Kowalski/9781572302327
• Mattick, R. P., & Clarke, J. C. (1998). Development and validation of measures of social phobia scrutiny fear and social interaction anxiety. Behaviour Research and Therapy, 36(4), 455–470. https://doi.org/10.1016/S0005-7967(97)10031-6
• Schlenker, B. R., & Leary, M. R. (1982). Social anxiety and self-presentation: A conceptualization and model. Psychological Bulletin, 92(3), 641–669. https://doi.org/10.1037/0033-2909.92.3.641
• Watson, D., & Friend, R. (1969). Measurement of social-evaluative anxiety. Journal of Consulting and Clinical Psychology, 33(4), 448–457. https://doi.org/10.1037/h0027806

13. Items of the Scale