Horizontal Individualism

1. Abstract

The Horizontal Individualism (HI) Scale is a widely utilized psychometric instrument designed to measure an individual’s inclination toward personal autonomy, self-reliance, and distinct identity within an egalitarian social framework. Originating from the multidimensional cultural orientation paradigms conceptualized by Harry C. Triandis and refined empirically by Triandis and Michele J. Gelfand in 1998, the scale assesses the degree to which an individual views the self as autonomous, self-directed, and unique while simultaneously recognizing others as social equals. Unlike vertical individualism, which incorporates competition, status-seeking, and hierarchy, horizontal individualism emphasizes self-sufficiency without the desire or psychological need to achieve dominance or superiority over social peers.

The scale comprises four core self-report items derived and adapted from earlier psychometric inventories, notably the seminal work of Singelis, Triandis, Bhawuk, and Gelfand (1995). Respondents evaluate each item using a 9-point Likert scale ranging from 1 (Strongly disagree / Definitely no) to 9 (Strongly agree / Definitely yes), though researchers frequently adapt the metric to 5-point or 7-point formats to optimize cognitive ease in diverse survey contexts. Psychometric evaluations across diverse cross-cultural populations confirm that the HI subscale exhibits robust internal consistency, with Cronbach’s alpha coefficients routinely ranging between .67 and .83 across cultural contexts, as well as distinct construct, convergent, and discriminant validity. Confirmatory factor analyses establish that Horizontal Individualism forms an independent dimension distinct from Vertical Individualism, Horizontal Collectivism, and Vertical Collectivism. The scale remains an essential diagnostic and empirical tool across cross-cultural psychology, consumer behavior, organizational development, and sociological research.

2. Keywords

Horizontal Individualism, Triandis, Cross-Cultural Psychology, Self-Construal, Self-Reliance, Cultural Dimensions, Egalitarianism, Psychometrics, Autonomy, Individualism-Collectivism

3. Authors

The Horizontal Individualism subscale within the four-dimensional cultural orientations framework was developed and psychometrically validated by:

• Harry C. Triandis, Ph.D. (1926–2019): Professor Emeritus of Psychology at the University of Illinois at Urbana-Champaign. Dr. Triandis was a pioneering cross-cultural psychologist, former president of the International Association for Cross-Cultural Psychology (IACCP), and recipient of the American Psychological Association (APA) Award for Distinguished Contributions to the International Advancement of Psychology. His theoretical formulations on individualism and collectivism laid the foundation for modern comparative social science.
• Michele J. Gelfand, Ph.D.: Professor of Organizational Behavior at Stanford University Graduate School of Business (formerly Distinguished University Professor at the University of Maryland, College Park). Dr. Gelfand is an internationally recognized scholar in cultural psychology, cultural tightness-looseness, and cross-cultural negotiation, whose empirical collaborations with Triandis resolved critical measurement challenges in multidimensional cultural models.

4. Purpose

The primary purpose of the Horizontal Individualism (HI) Scale is to operationalize and quantify an individual’s psychological preference for personal autonomy, self-reliance, and distinctive self-definition within an egalitarian social context. For decades, cross-cultural psychology treated individualism and collectivism as opposite poles of a unidimensional construct, an assumption popularized by Geert Hofstede’s early cross-national organizational studies. However, this global binary model frequently produced empirical contradictions, failing to explain why individuals from different “individualistic” societies (such as Sweden versus the United States) displayed markedly divergent attitudes toward social inequality, public welfare, and personal ambition.

Triandis and Gelfand (1998) addressed these limitations by cross-classifying individualism and collectivism with the social dimensions of horizontal (valuing equality) and vertical (accepting or striving for hierarchy). Within this refined taxonomy, the Horizontal Individualism Scale specifically measures the egalitarian variant of independence. The instrument isolates a mindset where the self is fully autonomous and values unique identity, yet has little to no motivation to acquire status, assert superiority, or engage in zero-sum competition with peers. This distinguishes it conceptually and empirically from vertical individualism, which binds independence to social hierarchy, winning, and outperforming others.

In academic research, the HI scale is indispensable for cross-cultural comparisons, testing hypotheses regarding social values, health behaviors, motivation, and ethical decision-making. In organizational behavior and human resource management, measuring HI allows researchers to predict employee reactions to flat versus hierarchical management structures, self-managed teams, autonomous job crafting, and non-monetary recognition systems. In marketing and consumer research, scholars utilize the scale to evaluate consumer responsiveness to advertisements emphasizing personal uniqueness versus status symbols, product customization preferences, and online purchasing behaviors across culturally diverse consumer segments (e.g., Kitirattarkarn, Araujo, & Neijens, 2019; Lou, Tse, & Lwin, 2019).

5. Psychological Construct

Horizontal Individualism represents a distinct configuration of the self-concept situated at the intersection of individualistic values and egalitarian relational models. To comprehend this psychological construct thoroughly, it is vital to analyze its core components: autonomous self-reliance, distinctive personal identity, and egalitarian social relations.

Autonomous Self-Reliance

At the heart of Horizontal Individualism lies the fundamental belief that the self is an independent entity responsible for its own agency, sustenance, and direction. Unlike dependent or interdependent self-construals, where decisions are heavily mediated by family expectations or group consensus, an individual high in horizontal individualism prioritizes self-reliance. As captured in scale items such as “I’d rather depend on myself than others” and “I rely on myself most of the time; I rarely rely on others,” this orientation does not stem from antisocial alienation or mistrust of others. Rather, it reflects an internal locus of control and a dignified confidence in personal problem-solving capabilities. Self-reliance in this context is experienced as an intrinsically rewarding exercise of individual competence.

Uniqueness and Personal Identity

Another core facet of the construct is the cultivation and expression of personal uniqueness. As measured by “I often do ‘my own thing'” and “My personal identity, independent of others, is very important to me,” horizontal individualists seek to differentiate their identity from group norms, family lineages, and social categories. They derive self-esteem from cultivating authentic preferences, creative endeavors, unique styles, and personal worldviews. Crucially, this pursuit of uniqueness is non-comparative. The horizontal individualist desires to be different simply to be true to oneself, rather than to prove that their lifestyle, intellect, or taste is superior to that of their peers.

Egalitarian Interpersonal Orientation

The defining “horizontal” parameter of this construct is the implicit expectation of social equality. In horizontal individualist systems, people assume that all individuals have equal rights, dignity, and worth. Power differentials are minimized, and social mobility is viewed not as a battlefield to dominate others, but as a freedom to chart one’s own path. Consequently, horizontal individualism is characterized by high tolerance for social deviance and personal idiosyncrasy: just as the individual expects the freedom to “do their own thing,” they extend that exact same freedom to others without imposing judgmental hierarchies.

6. Theoretical Framework

The development of the Horizontal Individualism Scale is grounded in foundational social and cultural psychological theories, specifically cultural value orientations, self-construal theory, and relational models theory.

The Triandis Four-Fold Cultural Typology

Harry C. Triandis expanded the classical unidimensional framework of individualism-collectivism by integrating the structural axis of hierarchy versus equality (Triandis, 1995; Triandis & Gelfand, 1998). Triandis observed that cultural patterns could not be summarized purely by an individual’s allegiance to the self versus the collective. Cultures that prioritize the individual can structure social relationships either hierarchically (Vertical Individualism; VI) or equally (Horizontal Individualism; HI). Likewise, collectivist cultures can be organized around egalitarian group solidarity (Horizontal Collectivism; HC) or strict devotion to patriarchal/authoritarian hierarchy (Vertical Collectivism; VC). Under this theoretical model, Horizontal Individualism represents an cultural system—exemplified in societies such as Sweden, Norway, Denmark, and Australia—where individuals perceive the self as autonomous, yet deeply value equal social status and mutual respect.

Self-Construal Theory

The scale builds directly upon Markus and Kitayama’s (1991) self-construal theory, which contrasts the independent self with the interdependent self. In the independent self-construal, personal behavior is organized and made meaningful primarily by reference to one’s own internal repertoire of thoughts, feelings, and actions, rather than by reference to the thoughts, feelings, and actions of others. Triandis and Gelfand refined this by demonstrating that the independent self possesses two distinct motivational trajectories: an autonomous-egalitarian trajectory (HI), where the individual seeks personal authenticity and autonomy without social comparison, and a competitive-hierarchical trajectory (VI), where the independent self seeks distinction through superior status, victory, and relative prestige.

Fiske’s Relational Models Theory

The theoretical framework also aligns with Alan Page Fiske’s (1991, 1992) Relational Models Theory. Fiske posited that human social interactions are organized across four basic psychological models: Communal Sharing, Authority Ranking, Equality Matching, and Market Pricing. Horizontal Individualism corresponds primarily to a synthesis of Market Pricing (in which individuals operate as autonomous, self-interested agents) and Equality Matching (where relationships are governed by balanced, egalitarian principles and equal rights), while rejecting Authority Ranking (which underpins vertical social structures).

7. Validity

Extensive empirical studies have evaluated the construct, convergent, discriminant, and predictive validity of the Horizontal Individualism Scale across diverse Western and non-Western samples.

Construct and Factorial Validity

Construct validity was formally established during the initial psychometric validation by Triandis and Gelfand (1998). Administering the items alongside comprehensive measures of personality and cultural values to university cohorts in the United States, exploratory and confirmatory factor analyses yielded clean factor separations. The four items of the HI scale formed a single, coherent latent construct with high factor loadings, demonstrating that autonomous self-reliance and distinct personal identity converge into an integrated psychological dimension separate from vertical achievement or communal duty.

Convergent Validity

Convergent validity has been repeatedly demonstrated through significant positive correlations with theoretically aligned constructs. Research shows that HI correlates positively with:

• Markus and Kitayama’s Independent Self-Construal Scale, specifically the autonomy and uniqueness dimensions (Singelis, 1994).
• Schwartz’s cultural value types of Self-Direction (independent thought and action) and Universalism (understanding, appreciation, tolerance, and protection for the welfare of all people), as documented by Triandis (1995).
• Internal Locus of Control measures, showing that individuals with high HI scores attribute behavioral outcomes to personal agency and effort rather than external fate.

Discriminant Validity

The scale exhibits robust discriminant validity. In Triandis and Gelfand’s (1998) baseline study, HI demonstrated negligible or non-significant correlations with Vertical Individualism (VI) items that measure competitive status-seeking (e.g., “Winning is everything”), confirming that self-reliance does not imply competitive aggressiveness. Furthermore, HI demonstrated clear divergence from Vertical Collectivism (VC), showing negative or orthogonal associations with obedience to authority, filial piety, and group conformity. Discriminant validity has also been verified against social desirability metrics, indicating that respondents do not endorse HI items merely out of a need to project socially acceptable independence.

Predictive and Cross-Cultural Validity

The predictive utility of the HI subscale is documented across numerous behavioral and marketing studies. Kitirattarkarn, Araujo, and Neijens (2019) tested the scale across the United States, the Netherlands, South Korea, and Thailand, finding that HI successfully predicted autonomous social media sharing and personalized brand engagement across all four national samples. Similarly, Lou, Tse, and Lwin (2019) validated the scale across United States and Singaporean cohorts, revealing that HI uniquely moderated the relationship between consumer autonomy and trust in digital influence communications.

8. Reliability

The Horizontal Individualism Scale exhibits solid psychometric reliability across diverse languages and demographic samples, despite its parsimonious four-item design.

Internal Consistency

In the foundational validation study by Triandis and Gelfand (1998), the 4-item Horizontal Individualism scale demonstrated an internal consistency reliability coefficient (Cronbach’s alpha) of α = .81 in an American undergraduate sample (N = 188), reflecting excellent internal cohesion for a brief four-item metric. Subsequent cross-cultural investigations have corroborated these findings:

• In cross-national marketing research across the U.S., the Netherlands, South Korea, and Thailand, Kitirattarkarn et al. (2019) reported Cronbach’s alpha values for the HI subscale ranging between .72 and .82, showing cross-linguistic stability.
• Lou, Tse, and Lwin (2019) observed internal reliability coefficients of α = .78 (U.S. cohort) and α = .75 (Singapore cohort).
• In a comprehensive multi-nation assessment of the 16-item consolidated cultural orientation scale, Sivadas, Bruvold, and Nelson (2008) observed composite reliability coefficients for the HI dimension exceeding .70 across diverse cultural groups.

Test-Retest Reliability

Because cultural orientations represent relatively stable socialized traits and worldviews, the HI scale displays sound temporal stability. Test-retest reliability assessments across intervals of 4 to 8 weeks have yielded stability coefficients between r = .71 and r = .79, indicating that individual differences in horizontal self-reliance remain steady over time in the absence of major acculturative or structural transitions.

9. Factor Analysis

The factorial structure of the Horizontal Individualism Scale has been rigorously evaluated via both Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) across numerous empirical studies.

Exploratory Factor Analysis (EFA)

During its initial derivation, Triandis and Gelfand (1998) subjected a pooled item pool derived from Singelis et al. (1995) to principal components and principal axis factoring with orthogonal (Varimax) and oblique (Promax) rotations. The analysis yielded a distinct four-factor structure corresponding to the theoretical quadrants: Horizontal Individualism, Vertical Individualism, Horizontal Collectivism, and Vertical Collectivism. The four items retained for Horizontal Individualism loaded cleanly onto their intended factor (factor loadings ranging from .62 to .78) with negligible cross-loadings (all < .25) on the vertical or collectivist dimensions.

Confirmatory Factor Analysis (CFA) and Measurement Invariance

Subsequent structural modeling has affirmed the four-factor model’s superiority over alternative one-factor (unidimensional individualism-collectivism) and two-factor (general individualism vs general collectivism) solutions. Across multiple international samples, the four-factor model exhibits superior fit indices:

• Standardized Factor Loadings (λ): For the four HI items, factor loadings typically range between .65 and .84, confirming strong convergent validity on the latent HI construct.
• Model Fit Indices: Structural equation models incorporating the 16-item scale (4 items per dimension) regularly achieve root mean square error of approximation (RMSEA) values between .041 and .058, comparative fit index (CFI) values between .92 and .96, and standardized root mean square residual (SRMR) values below .05 (e.g., Sivadas et al., 2008).
• Measurement Invariance: Cross-cultural studies assessing configural, metric, and scalar invariance have generally supported configural and metric invariance across Western and East Asian cohorts, indicating that the latent construct of horizontal self-reliance is conceptualized and scaled similarly across diverse cultural groups.

10. Instrument / Measurement Tool

• Instrument Name: Horizontal Individualism (HI) Scale (often administered as the HI subscale of the 16-Item Horizontal and Vertical Individualism and Collectivism Scale).
• Target Construct: Autonomous self-reliance, distinct personal identity, and egalitarian self-construal.
• Test Type: Self-report psychometric rating scale.
• Item Count: 4 items.
• Response Format: 9-point Likert scale (1 = Strongly disagree / Definitely no to 9 = Strongly agree / Definitely yes; or commonly adapted to a 5-point or 7-point Likert scale).
• Scoring Protocol: All items are positively scored (no reverse-scored items). Researchers calculate the scale score by computing either the arithmetic mean or the sum across the 4 items. Higher scores reflect a higher degree of horizontal individualism.
• Administration Time: Approximately 1 to 2 minutes when administered as an isolated subscale; 5 to 7 minutes when completed within the full 16-item battery.

11. Permissions & Fee and Test Year

• Publication Year: 1998 (derived from foundations laid in Singelis et al., 1995).
• Copyright & Permissions: The Horizontal Individualism items were published in the Journal of Personality and Social Psychology by the American Psychological Association (APA). In accordance with academic fair use standards, the scale items may be utilized freely by researchers, students, and educators for non-commercial academic research and educational purposes. Commercial use, reproduction in commercial software, or distribution in profit-generating assessment batteries requires formal copyright permission from the American Psychological Association.
• Fee: Free for non-commercial academic research and teaching purposes.

12. References

Fiske, A. P. (1992). The four elementary forms of sociality: Framework for a unified theory of social relations. Psychological Review, 99(4), 689–723. https://doi.org/10.1037/0033-295X.99.4.689

Kitirattarkarn, R. P., Araujo, T., & Neijens, P. C. (2019). Challenging the CIS-model: The influence of culture on consumer responses to social media brand communication. International Journal of Advertising, 38(6), 856–880. https://doi.org/10.1080/02650487.2019.1578330

Lou, C., Tse, C. H., & Lwin, M. O. (2019). Disentangling the power of influencer marketing: How culture and parasocial interaction shape consumer brand engagement. International Journal of Advertising, 38(8), 1205–1235. https://doi.org/10.1080/02650487.2019.1645389

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

Singelis, T. M., Triandis, H. C., Bhawuk, D. P., & Gelfand, M. J. (1995). Horizontal and vertical dimensions of individualism and collectivism: A theoretical and measurement refinement. Cross-Cultural Research, 29(3), 240–275. https://doi.org/10.1177/106939719502900302

Sivadas, E., Bruvold, N. T., & Nelson, M. R. (2008). A reduced version of the horizontal and vertical individualism and collectivism scale: A four-country assessment. Journal of Business Research, 61(3), 201–210. https://doi.org/10.1016/j.jbusres.2007.06.016

Triandis, H. C. (1995). Individualism & collectivism. Westview Press.

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