Attitudes Towards Intellectual Disability Scale (EADI)

Abstract

The Attitudes Towards Intellectual Disability Scale (known by its Spanish acronym EADI, Escala de Actitudes hacia la Discapacidad Intelectual) is a specialized psychometric questionnaire designed to assess workplace attitudes toward persons with intellectual disability. Developed by Alicia Boluarte Carbajal, Martin Salazar-Conde, Arantxa N. Sánchez Boluarte, Danilo Sánchez Coronel, and Brian Norman Peña-Calero (2023), the instrument fills an essential measurement gap in organizational psychology, vocational rehabilitation, and labor diversity evaluation. The scale comprises 10 items organized across two distinct, correlated latent dimensions: Perception (evaluating cognitive judgments regarding competence, equity, organizational contribution, and learning potential) and Social Distance (capturing affective discomfort, interpersonal avoidance, and reluctance to share cooperative occupational roles). Items are scored on a standardized 5-point Likert scale ranging from 1 (Totalmente en desacuerdo / Strongly Disagree) to 5 (Totalmente de acuerdo / Strongly Agree). Psychometric evaluation across occupational laborer cohorts confirmed strong structural validity using both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), demonstrating excellent model fit (χ² = 84.45, df = 34, CFI = 0.99, TLI = 0.99, RMSEA = 0.08 [90% CI: 0.06–0.10], SRMR = 0.04) and explaining 70% of the total variance. The subscales exhibit high internal consistency, with McDonald’s omega (ω) reaching 0.93 for Perception (α = 0.86) and 0.92 for Social Distance (α = 0.83). The EADI represents a rigorous, evidence-based instrument for human resource auditing, occupational intervention research, and the empirical modeling of workplace inclusion.

Keywords

Attitudes Towards Intellectual Disability, EADI, Perception, Social Distance, Workplace Inclusion, Organizational Psychometrics, Labor Equality, Neurodiversity in the Workplace, Factor Analysis, Scale Validation

Authors

The Attitudes Towards Intellectual Disability Scale (EADI) was developed and validated by a multidisciplinary team of psychometricians, health researchers, and behavioral scientists:

• Alicia Boluarte Carbajal — Universidad César Vallejo, Lima, Peru. Correspondence: [email protected].
• Martin Salazar-Conde — Universidad César Vallejo, Lima, Peru.
• Arantxa N. Sánchez Boluarte — Department of Global Health, University of Washington, Seattle, Washington, United States.
• Danilo Sánchez Coronel — Universidad César Vallejo, Lima, Peru.
• Brian Norman Peña-Calero — Advances in Psychological Measurement Study Group, Lima, Peru.

Purpose

The primary purpose of the Attitudes Towards Intellectual Disability Scale (EADI) is to provide an empirically sound, psychometrically robust, and brief measurement instrument tailored specifically to organizational, corporate, and vocational settings. Global legal mandates—such as the United Nations Convention on the Rights of Persons with Disabilities (CRPD) and national labor quota regulations—have increasingly opened doors for neurodivergent individuals and persons with intellectual disabilities to enter the competitive workforce. However, legislative compliance does not automatically translate into psychological inclusion, social integration, or interpersonal acceptance.

Historically, measures of attitudes toward disability have focused on generalized community samples, educational integration (e.g., mainstream schooling), or broad physical impairments, leaving the specific dynamics of workplace collaboration largely unexamined. In vocational contexts, coworkers and supervisors frequently hold implicit and explicit biases regarding productivity, cognitive capability, safety, reliability, and supervisory burden. These biased mental schemas generate subtle or overt interpersonal friction, including social exclusion, task marginalization, paternalism, and wage disparities.

The EADI directly addresses this operational void by systematically capturing two core operational domains:

• Cognitive Beliefs Regarding Labor Competence and Rights (Perception): Assessing whether employees believe that individuals with intellectual disabilities can achieve adequate productivity with proper training, whether they contribute positively to organizational climate, and whether they deserve equitable remuneration and institutional opportunities.
• Behavioral and Affective Reluctance to Interact (Social Distance): Measuring avoidance tendencies, reluctance to share team projects, resistance to assigning core responsibilities, and emotional discomfort working under or alongside an individual with an intellectual disability.

In applied settings, organizational psychologists and human resource professionals utilize the EADI to conduct baseline diversity audits, evaluate the efficacy of inclusive leadership and disability awareness workshops, assess workplace climate prior to supported employment placements, and monitor longitudinal interventions aimed at reducing stigma in blue-collar and corporate settings.

Psychological Construct

The construct measured by the EADI is multidimensional, conceptualizing attitudes toward intellectual disability through a tri-component framework comprising cognitive appraisals, affective responses, and behavioral intentions within work environments. Rather than viewing attitude as a single monolithic spectrum of “favorable versus unfavorable,” the instrument distinguishes between ideological/evaluative judgments and proximal interpersonal dynamics.

1. Perception (Percepción)

The Perception dimension measures explicit cognitive beliefs concerning the occupational capabilities, adaptive potential, organizational benefits, and fundamental employment rights of individuals with intellectual disabilities. It encompasses several theoretical sub-facets:

• Task Efficacy and Trainability: The belief that given systematic task instruction, vocational coaching, and reasonable workplace accommodations, individuals with intellectual disability can execute job duties productively and reliably (e.g., Item 1, Item 4).
• Organizational and Socio-Emotional Value: Recognition of the positive impact neurodiverse employees introduce into company culture, social cohesion, and institutional citizenship (e.g., Item 2, Item 3).
• Distributive Justice and Equity: Endorsement of wage parity, fair economic compensation, and equitable performance expectations, resisting the systemic practice of labor exploitation or underpaid sheltering (e.g., Item 5).

Higher scores on the Perception dimension reflect an affirming, rights-based, and capability-focused cognitive orientation that aligns with modern social models of disability.

2. Social Distance (Distancia Social)

The Social Distance dimension captures the affective and behavioral-intentional willingness of workers to engage in close, collaborative, and subordinate relationships with persons having intellectual disabilities. Rooted in classical social psychological frameworks, social distance manifests not merely as hostility, but as subtle avoidance, desire for organizational segregation, and task withholding:

• Cooperative Discomfort: Anticipated emotional unease, awkwardness, or anxiety when assigned to the same operational team (e.g., Item 6).
• Responsibility Sharing: Reluctance to depend on or share mutual accountability for task outcomes with an intellectually disabled colleague (e.g., Item 7, Item 8).
• Hierarchical Inversion and Supervision Resistance: Distinct discomfort with non-traditional authority hierarchies, specifically having a supervisor or direct leader with an intellectual or developmental condition (e.g., Item 9).
• Interpersonal Segregation: Preference for strictly bureaucratic, aloof, or emotionally distant interactions, blocking the formation of collegial solidarity and informal workplace social networks (e.g., Item 10).

When scored in the direction of the raw items, elevated scores on this factor indicate heightened interpersonal prejudice, relational reservation, and segregationist inclinations.

Theoretical Framework

The architectural foundation of the EADI integrates three foundational psychological paradigms: the ABC Model of Attitudes, Bogardus’s Social Distance Theory, and the Social Model of Disability.

The Tripartite (ABC) Model of Attitudes

Formulated by early social psychologists such as Rosenberg and Hovland, and subsequently expanded in social cognitive literature (e.g., Eagly & Chaiken), the ABC model posits that an attitude consists of three interacting components: Affect (feelings and physiological arousal), Behavior (action tendencies and observable conduct), and Cognition (beliefs, values, and perceptual frameworks). The EADI captures these interconnected systems by contrasting broad cognitive values (Perception) with direct affective-behavioral predispositions (Social Distance). Research repeatedly demonstrates that individuals may express favorable cognitive sentiments (e.g., “Everyone deserves equal rights”) while simultaneously exhibiting high behavioral avoidance or discomfort when personal proximity and mutual task interdependence are introduced.

Bogardus’s Social Distance Paradigm

Emory S. Bogardus (1925) introduced social distance to quantify the degree of closeness, acceptance, or intimacy a person is willing to grant members of outgroups. In the context of occupational stigma, social distance reflects the psychological boundaries workers maintain to preserve personal comfort, group status, or task certainty. The EADI operationalizes social distance through specific vocational scenarios: sharing a work station, participating in a shared project team, delegating core operational responsibilities, and accepting organizational hierarchy. The presence of social distance in employment settings functions as an invisible barrier, often driving neurodivergent employees into isolated roles, lower-skilled repetitive tasks, and social marginalization.

Medical versus Social and Rights-Based Models of Disability

Historically, the medical model pathologized intellectual disability as an intrinsic biological deficit requiring paternalistic care, confinement, or sheltered employment. In contrast, the social model developed by Oliver (1990) and reinforced by the United Nations Convention on the Rights of Persons with Disabilities asserts that disability results from the systemic interaction between individual impairments and environmental, attitudinal, and institutional barriers. The EADI was explicitly constructed under this modern socio-ecological paradigm, framing workplace competence not as an unalterable deficit, but as a dynamic interaction that flourishes when appropriate institutional accommodation, training, and equitable organizational culture are provided.

Validity

The psychometric validation of the EADI followed rigorous international test development standards established by the American Psychological Association (APA), the American Educational Research Association (AERA), and the National Council on Measurement in Education (NCME).

Content Validity

Initial item generation derived from a systematic review of the vocational rehabilitation and occupational stigma literature, combined with focus groups and cognitive pre-testing interviews with active laborers. The preliminary item pool underwent rigorous expert panel evaluation involving 15 independent judges with expertise in psychometrics, organizational psychology, and disability studies. Judges assessed each item for clarity, representativeness, relevance, and theoretical alignment using Aiken’s V coefficient. Items exhibiting Aiken’s V values below 0.80 were eliminated or revised, yielding an optimized 10-item instrument with exceptional content validity.

Construct and Structural Validity

Structural validity was assessed through sequential exploratory and confirmatory factor analytic designs administered to occupational workers (mean age = 39.17 years). Initial analyses demonstrated that two candidate items (originally numbered items 2 and 6 in preliminary piloting) exhibited inadequate factorial behavior, low communalities, and ambiguous factor saturations; their removal substantially clarified the latent structure. The resulting 10-item, two-factor model demonstrated exceptional goodness-of-fit indices:

• Chi-Square / Degrees of Freedom Ratio: χ² = 84.45, df = 34 (χ²/df = 2.48, well within the recommended threshold of ≤ 3.0).
• Comparative Fit Index (CFI): 0.99 (exceeding the ≥ 0.95 benchmark for excellent fit).
• Tucker-Lewis Index (TLI): 0.99 (exceeding the ≥ 0.95 benchmark).
• Root Mean Square Error of Approximation (RMSEA): 0.08 with a 90% confidence interval of [0.06, 0.10].
• Standardized Root Mean Square Residual (SRMR): 0.04 (well below the conservative 0.05 cutoff).

The two latent factors exhibited a moderate, meaningful inter-factor correlation (r = .63), confirming that while Perception and Social Distance represent interrelated dimensions of an overarching attitudinal construct, they capture distinct psychological variance and should not be collapsed into an undifferentiated unidimensional composite.

Reliability

The internal consistency of the EADI was rigorously evaluated using both classic parametric estimates (Cronbach’s alpha) and modern structural equation-based coefficients (McDonald’s omega). Because Cronbach’s alpha relies on the assumption of tau-equivalence (equal factor loadings across all items), which is rarely met in psychological scales, McDonald’s ω provides an accurate, congeneric index of measurement precision.

• Dimension 1: Perception (Items 1–5)
  • Cronbach’s Alpha (α): 0.86
  • McDonald’s Omega (ω): 0.93
• Dimension 2: Social Distance (Items 6–10)
  • Cronbach’s Alpha (α): 0.83
  • McDonald’s Omega (ω): 0.92

Both dimensions comfortably exceed conventional thresholds for academic research (≥ 0.70) and clinical/organizational decision-making (≥ 0.80–0.90). The total scale explained approximately 70% of the common variance, confirming that random measurement error is minimal and that individual differences in observed scores reflect true differences in latent attitude dimensions.

Factor Analysis

The latent dimensionality of the EADI was tested using a dual exploratory-to-confirmatory factor analytic strategy:

Exploratory Factor Analysis (EFA)

Prior to factor extraction, sampling adequacy and inter-item correlation matrices were evaluated. The Kaiser-Meyer-Olkin (KMO) index exceeded 0.85, and Bartlett’s Test of Sphericity reached high statistical significance (p < .001), rejecting the null hypothesis that the correlation matrix was an identity matrix. Unweighted Least Squares (ULS) or Robust Maximum Likelihood estimation with Promax/Oblomax oblique rotations was employed due to the hypothesized theoretical association between cognitive perception and social distance. Parallel analysis supported a two-factor solution, accounting for 70% of the total cumulative variance.

Confirmatory Factor Analysis (CFA)

The structural framework derived from EFA was evaluated via Confirmatory Factor Analysis using structural equation modeling (SEM). The two-factor oblique model exhibited robust factor loadings across all ten indicators. Standardized factor loadings (λ) for indicators on their respective latent constructs were uniformly high and statistically significant (all λ ≥ 0.65, p < .001), indicating strong construct saturation. Model modification indices confirmed the absence of significant cross-loadings or unmodeled residual covariances. The latent inter-factor correlation was estimated at .63, confirming significant shared variance while maintaining statistical divergence sufficient to justify multidimensional scoring.

Instrument / Measurement Tool

• Official Title: Attitudes Towards Intellectual Disability Scale / Escala de Actitudes hacia la Discapacidad Intelectual (EADI)
• Test Type: Self-report psychometric inventory / Organizational assessment tool
• Format: Paper-and-pencil or computerized/electronic administration via web survey platforms
• Item Count: 10 items
• Dimensions / Subscales:
  • Perception (Percepción): 5 items (Items 1, 2, 3, 4, 5)
  • Social Distance (Distancia Social): 5 items (Items 6, 7, 8, 9, 10)
• Response Scale: 5-point Likert scale (1 = Totalmente en desacuerdo / Strongly Disagree, 2 = En desacuerdo / Disagree, 3 = Indiferente / Neutral, 4 = De acuerdo / Agree, 5 = Totalmente de acuerdo / Strongly Agree)
• Administration Time: Approximately 3 to 5 minutes
• Target Population: Human working populations (laborers, blue-collar workers, white-collar employees, supervisors, and administrative personnel); tested on adults (sample average age: 39.17 years)
• Scoring Instructions:
  • Subscale 1 (Perception): Sum or average scores for Items 1 through 5. Higher scores indicate stronger positive perceptions regarding the workplace competence, equal rights, and organizational contributions of workers with intellectual disabilities.
  • Subscale 2 (Social Distance): Sum or average scores for Items 6 through 10. Higher raw scores indicate greater interpersonal avoidance, discomfort, and reluctance to cooperate. If computing an overall “Positive Attitude” composite score, reverse-score Items 6 through 10 (where 1 becomes 5, 2 becomes 4, 3 remains 3, 4 becomes 2, and 5 becomes 1) prior to calculating the global sum.

Permissions & Fee and Test Year

Publication Year: 2023

Permissions and Licensing: The Attitudes Towards Intellectual Disability Scale (EADI) is published as an open-access scientific instrument distributed under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0). Under this license, researchers, practitioners, educators, and organizations are permitted to freely copy, reproduce, distribute, translate, and adapt the measure for academic research, organizational auditing, and training interventions, provided appropriate credit is given to the original authors and the source publication.

Fee: There is no fee or royalty required for using, administering, or adapting the scale for research, educational, or professional assessment purposes.

References

• Bogardus, E. S. (1925). Measuring social distance. Journal of Applied Sociology, 9, 299–308.
• Carbajal, A. B., Salazar-Conde, M., Sánchez Boluarte, A. N., Coronel, D. S., & Peña-Calero, B. N. (2023). Development and psychometric properties of the Attitudes Towards Intellectual Disability Scale in the workplace. Interacciones, 9, Article e366. https://doi.org/10.24016/2023.v9.366
• Eagly, A. H., & Chaiken, S. (1993). The psychology of attitudes. Harcourt Brace Jovanovich College Publishers.
• Oliver, M. (1990). The politics of disablement: A sociological approach. St. Martin’s Press.
• United Nations. (2006). Convention on the Rights of Persons with Disabilities. United Nations Treaty Series, 2515, 3.

Items of the Scale