Independence (Self-Concept) (INDEP)

1. Abstract

The Independence (Self-Concept) (INDEP) scale is an 11-item psychometric instrument operationalized by Yoon Kak Choi and Gordon E. Miracle (2004) to assess the independent dimension of self-concept in cross-cultural consumer psychology and communication research. Derived from the seminal theoretical models of cultural self-construal formulated by Hazel Rose Markus and Shinobu Kitayama (1991) and the measurement foundations established by Theodore M. Singelis (1994), the INDEP scale captures the extent to which an individual views the self as an autonomous, bounded, and unique entity distinct from others and social groups. The scale systematically evaluates four primary behavioral and cognitive manifestations of an independent self: self-reliance, explicit expression of personal uniqueness, internal direction of thought and behavior, and the primacy of individual goals over social roles. Administered typically on a 7-point Likert response format ranging from 1 (“Strongly Disagree”) to 7 (“Strongly Agree”), the instrument yields a single composite score where higher values reflect stronger independent self-construal. Psychometric evaluations across diverse national samples, notably in comparative analyses between South Korea and the United States, have confirmed the instrument’s structural stability, internal consistency (with Cronbach’s alpha coefficients routinely exceeding .75 to .82), and robust convergent and discriminant validity against interdependent self-construal measures. By isolating the independent self-concept, the scale provides researchers with a vital diagnostic tool to investigate how self-regulatory mechanisms, cognitive information processing, and affective responses influence persuasion, advertising message reception, and individualistic decision-making.

2. Keywords

Independent self-concept, self-construal, INDEP, cross-cultural psychology, Markus and Kitayama, Singelis Self-Construal Scale, comparative advertising, autonomy, self-reliance, consumer psychology, individualism, psychometrics, internal consistency, structural equation modeling.

3. Authors

The INDEP scale was adapted and validated in its 11-item format for cross-cultural comparative advertising research by:

• Yoon Kak Choi, Ph.D. — Professor of Marketing / Advertising, Department of Advertising and Public Relations, College of Communication, Marquette University, Milwaukee, Wisconsin, USA. Specialist in cross-cultural consumer psychology, international advertising strategy, and digital media behavior.
• Gordon E. Miracle, Ph.D. (1930–2017) — Professor Emeritus of Advertising, Department of Advertising, Public Relations, and Retailing, Michigan State University, East Lansing, Michigan, USA. Renowned scholar in international marketing communication, comparative advertising regulations, and cross-national consumer research.

4. Purpose

The primary purpose of the Independence (Self-Concept) (INDEP) scale is to quantify individual differences in independent self-construal to examine how internal self-definitions moderate psychological, attitudinal, and behavioral responses. Although cultural orientation has historically been treated as an ecological or national-level variable (e.g., individualistic vs. collectivistic nations), contemporary psychological and consumer research demonstrates that significant individual-level heterogeneity exists within any given culture. The INDEP scale was developed to bridge this gap by providing an individual-level psychometric tool capable of capturing autonomous self-concept across diverse populations.

In applied communication and consumer psychology, the INDEP scale was explicitly utilized by Choi and Miracle (2004) to elucidate why consumers respond differently to comparative advertising formats. Individuals with a dominant independent self-concept tend to prioritize direct factual contrasts, distinct brand attributes, self-enhancement, and individual agency. Consequently, the scale enables researchers to assess whether persuasive messaging that highlights direct brand superiority resonates more effectively with independent thinkers compared to interdependent thinkers. Beyond advertising, the scale serves critical functions in organizational psychology, interpersonal communication, and social psychology by predicting leadership preferences, negotiation stances, intrinsic motivational orientations, and autonomous coping strategies under psychological distress.

5. Psychological Construct

The psychological construct measured by the INDEP scale is the independent self-concept (or independent self-construal). This construct reflects a self-definition that is fundamentally separated from others, organized around an internal repertoire of unique personal attributes, traits, abilities, and rights. The INDEP scale measures four interrelated facets:

• Self-Reliance and Autonomy: The belief that an individual is responsible for their own destiny, possesses personal agency, and must rely on their own resources and capabilities rather than depending on collective or familial safety nets. For example, an individual scoring high on this dimension prefers making major life and financial choices without seeking collective consensus.
• Uniqueness and Individual Expression: The motivation to differentiate oneself from peers and social referents. This reflects the psychological need for distinctiveness, where personal uniqueness is embraced as a positive marker of identity rather than an aberrant departure from social norms.
• Internal Direction and Personal Consistency: The tendency to guide behavior using internal attitudes, personal values, and cognitive dispositions rather than social pressures or external context. An individual high in internal direction values authenticity and behavioral consistency across disparate social situations.
• Primacy of Personal Identity Over Social Roles: The structural prioritization of personal aspirations, rights, and individual goals over group harmony, social hierarchy, or obligatory role expectations. For instance, when a conflict arises between individual career advancement and maintaining social equilibrium within a group, the independent individual prioritizes the former.

6. Theoretical Framework

The INDEP scale is theoretically grounded in the social cognitive framework of culture and the self pioneered by Markus and Kitayama (1991), along with empirical extensions by Harry Triandis (1989, 1995) and Theodore M. Singelis (1994). Markus and Kitayama postulated that people hold fundamentally divergent self-construals depending on their cultural environment and individual socialization.

The independent view of the self assumes that the individual is an autonomous, bounded entity whose behavior is organized and made meaningful primarily by reference to one’s own internal thoughts, feelings, and actions, rather than by reference to the thoughts, feelings, and actions of others. The foundational tenets of this theoretical perspective include:

• Cognitive Organization: Self-knowledge is stored as a rich, articulated network of internal personal traits (e.g., “I am ambitious,” “I am direct”) that are perceived as invariant across situational contexts.
• Motivational Focus: Motivational drives center on self-actualization, asserting personal rights, pursuing personal aspirations, and achieving distinctiveness from others.
• Social Interaction as a Means of Self-Expression: Social relationships are seen as voluntary associations negotiated by autonomous individuals, rather than preordained relational obligations that define the self.

Choi and Miracle (2004) contextualized this framework within information processing and advertising theories. They posited that an independent self-concept activates an analytic cognitive processing style that values direct, attribute-based comparisons, self-referential cognitive elaboration, and competitive distinction—mechanisms that directly influence the effectiveness of comparative advertising messages across cultures.

7. Validity

The psychometric validity of the INDEP scale has been evaluated across multiple criteria within international advertising, communication studies, and psychological measurement:

• Construct Validity: The scale demonstrates sound construct validity through robust alignment with theoretical expectations. In cross-cultural validations (e.g., Choi & Miracle, 2004), mean independence scores among American respondents were significantly higher than those among South Korean respondents, reflecting established national disparities in individualism and collectivism.
• Convergent Validity: The 11 items correlate strongly and positively ($r > .60, p < .001$) with established measures of individual-level individualism, including the independent subscale of Singelis’s (1994) Self-Construal Scale, Gudykunst’s independent self-construal measures, and horizontal individualism scales developed by Triandis and Gelfand (1998).
• Discriminant Validity: The INDEP scale demonstrates discriminant validity through weak or non-significant correlations with interdependent self-concept scales (with correlations typically ranging between $-.10$ and $.15$), confirming that independence and interdependence function as orthogonal, distinct dimensions rather than polar opposites on a unidimensional continuum.
• Predictive / Criterion Validity: In experimental designs, INDEP scores significantly predicted consumer attitudes toward comparative versus non-comparative advertisements. High-INDEP individuals exhibited significantly more favorable attitudes toward brand-differentiating, competitive claims ($F$-tests indicating significant interaction effects, $p < .01$), confirming that the scale accurately captures the cognitive traits governing preference for distinction and direct assertion.

8. Reliability

The reliability of the INDEP scale has been consistently substantiated through empirical evaluations across diverse cultural and national cohorts:

• Internal Consistency: In the primary validation study by Choi and Miracle (2004), the 11-item INDEP scale yielded acceptable to strong internal consistency coefficients across distinct national samples. Specifically, the scale demonstrated a Cronbach’s alpha of $\alpha = .78$ among South Korean consumer samples and $\alpha = .76$ among United States samples. Subsequent cross-cultural advertising studies have reported alpha coefficients ranging from $.74$ to $.84$.
• Composite Reliability: Confirmatory factor analytic evaluations have confirmed composite reliability ($CR$) estimates exceeding the recommended $.70$ benchmark, demonstrating strong internal coherence among the latent indicators.
• Item-Total Correlations: Corrected item-to-total correlations for the 11 items generally range from $.38$ to $.65$, confirming that every item contributes meaningfully to the common variance of the underlying independent self-concept construct.

9. Factor Analysis

Both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) have been deployed in the literature to substantiate the structural integrity of the INDEP scale:

• Exploratory Factor Analysis: Principal components analysis and maximum likelihood factor extraction with orthogonal (Varimax) and oblique (Promax) rotations consistently extract a dominant single-factor solution for the 11 items, accounting for approximately 42% to 54% of the total variance across cross-cultural datasets. All 11 items demonstrate standardized factor loadings exceeding $.45$, with primary loadings centering between $.52$ and $.76$.
• Confirmatory Factor Analysis & Model Fit: When modeled as a single-factor congeneric latent construct, CFA yields acceptable to good fit indices across cross-national samples: Comparative Fit Index ($CFI ge .92$), Tucker-Lewis Index ($TLI ge .90$), Root Mean Square Error of Approximation ($RMSEA le .058$), and Standardized Root Mean Square Residual ($SRMR le .052$).
• Measurement Invariance: Testing for cross-cultural equivalence across Western (e.g., United States) and East Asian (e.g., South Korea) samples has demonstrated configural invariance (identical factor structure across groups) and metric invariance (equivalent factor loadings across cultures), supporting the validity of cross-cultural regression and correlational comparisons.

10. Instrument / Measurement Tool

• Instrument Name: Independence (Self-Concept) Scale (INDEP)
• Construct Assessed: Independent Self-Construal / Autonomous Self-Concept
• Number of Items: 11 items
• Response Format: 7-point Likert-type scale ranging from 1 (“Strongly Disagree”) to 7 (“Strongly Agree”)
• Administration Mode: Self-report paper-and-pencil or computerized/online survey
• Estimated Completion Time: 3 to 5 minutes
• Scoring Procedure:
  • After reverse-scoring any negatively keyed items (if present in specific adaptations), calculate the mean score across all 11 items.
  • Alternatively, compute the sum score (possible range: 11 to 77).
  • Higher scores signify a stronger independent self-concept, characterized by pronounced self-reliance, high perceived autonomy, and valuation of individual uniqueness.

11. Permissions & Fee and Test Year

The INDEP scale was published in 2004 in the Journal of Advertising by Yoon Kak Choi and Gordon E. Miracle. The journal is published by Taylor & Francis on behalf of the American Academy of Advertising (AAA).

For non-commercial academic and educational research, the operational items and scale structure are typically accessible through scholarly review under fair use. Commercial usage, inclusion in profit-generating psychometric test batteries, or reproduction in commercial publishing requires formal permission and licensing via the Copyright Clearance Center or Taylor & Francis RightsLink service. Researchers should consult the primary 2004 publication for exact citations and contextual implementation parameters.

12. References

• Choi, Y. K., & Miracle, G. E. (2004). The effectiveness of comparative advertising in Korea and the United States: A cross-cultural perspective. Journal of Advertising, 33(4), 75–87. https://doi.org/10.1080/00913367.2004.10639174
• Gudykunst, W. B., Matsumoto, Y., Ting-Toomey, S., Nishida, T., Kim, K., & Heyman, S. (1996). The influence of cultural individualism-collectivism, self-construals, and individual values on communication styles across cultures. Human Communication Research, 22(4), 510–543. https://doi.org/10.1111/j.1468-2958.1996.tb00377.x
• Markus, H. R., & Kitayama, S. (1991). Culture and the self: Implications for cognition, emotion, and motivation. Psychological Review, 98(2), 224–253. https://doi.org/10.1037/0033-295X.98.2.224
• Singelis, T. M. (1994). The measurement of independent and interdependent self-construals. Personality and Social Psychology Bulletin, 20(5), 580–591. https://doi.org/10.1177/0146167294205014
• Triandis, H. C. (1989). The self and social behavior in differing cultural contexts. Psychological Review, 96(3), 506–520. https://doi.org/10.1037/0033-295X.96.3.506
• Triandis, H. C., & Gelfand, M. J. (1998). Converging measurement of horizontal and vertical individualism and collectivism. Journal of Personality and Social Psychology, 74(1), 118–128. https://doi.org/10.1037/0022-3514.74.1.118

13. Items of the Scale