Intentions Towards Infidelity Scale

Abstract

The Intentions Towards Infidelity Scale (ITIS) is a psychometric instrument designed to measure an individual’s subjective behavioral intentions to commit romantic and sexual infidelity within committed partnerships. Developed by Daniel Nelson Jones, Sally Gayle Olderbak, and Aurelio José Figueredo, the scale bridges a critical methodological gap in interpersonal relationship research: while general attitudes toward infidelity and broad personality traits often fail to predict actual infidelity due to distal cognitive and normative barriers, behavioral intentions provide a proximal, actionable determinant of future relationship transgressions. The ITIS comprises 7 self-report items evaluated on a 7-point Likert-type bipolar scale ranging from -3 (Not at all Likely) to +3 (Extremely Likely). Psychometric evaluations demonstrate a robust unidimensional factor structure accounting for substantial shared variance across items. The internal consistency of the scale is reliable across diverse university and community samples, with Cronbach’s alpha coefficients ranging between .70 and .81. Convergent validity is evidenced by moderate-to-strong positive associations with past infidelity behavior ($r \approx .60$), unrestricted sociosexual orientation (SOI), short-term mating effort, avoidant attachment, impulsive sensation seeking, and aggression/hostility. Conversely, the instrument exhibits significant negative correlations with relationship satisfaction, long-term mating orientation, conscientiousness, and agreeableness. Longitudinal predictive evaluations indicate that baseline ITIS scores predict significant decrements in relationship satisfaction up to 6 months post-assessment, as well as subsequent relationship dissolution and actual infidelity infractions over 12-month follow-up intervals. Furthermore, structural path analyses confirm that the ITIS fully mediates the predictive relationships between distal personality constructs (such as the Alternative Five and Big Five) and actual infidelity behavior. The scale provides clinicians and researchers with an efficient, psychometrically sound instrument that takes less than one minute to administer.

Keywords

Intentions Towards Infidelity Scale, infidelity, behavioral intentions, Theory of Planned Behavior, sociosexuality, relationship dissolution, romantic commitment, extra-dyadic behavior, psychometrics, attachment avoidance

Authors

The Intentions Towards Infidelity Scale was authored by an academic collaboration between psychometricians and personality/social psychologists specializing in evolutionary psychology, life history strategy, and romantic relationship dynamics:

• Daniel Nelson Jones, Ph.D.: Primary investigator and scale architect; affiliated during scale development with the Department of Psychology at the University of British Columbia (Vancouver, BC, Canada) and subsequently Professor of Management and Organizational Behavior / Psychology at the University of Nevada, Reno. Dr. Jones is widely recognized for his research on the Dark Triad, deceptive interpersonal behavior, and mating strategies. Correspondence: [email protected].
• Sally Gayle Olderbak, Ph.D.: Co-author; affiliated with the Department of Psychology at the University of Arizona (Tucson, AZ, USA) and subsequently Senior Researcher at Ulm University, Germany. Dr. Olderbak specializes in socio-emotional functioning, emotional intelligence, structural equation modeling, and longitudinal dyadic research.
• Aurelio José Figueredo, Ph.D.: Co-author; Professor of Psychology and Director of the Ethology and Evolutionary Psychology Laboratory at the University of Arizona. Dr. Figueredo is an internationally renowned quantitative psychologist specializing in human life history theory, evolutionary psychometrics, behavioral genetics, and multivariate modeling.

Purpose

Infidelity represents one of the most psychologically disruptive and empirically pervasive catalysts for relationship distress, domestic conflict, clinical depression, and legal divorce (Daly, Wilson, & Weghorst, 1982; Hall & Fincham, 2005). Despite its profound personal and socio-legal repercussions, predicting precisely who is predisposed to violate romantic exclusivity has historically presented serious psychometric hurdles. Prior assessment tools generally focused on two domains: general moral or evaluative attitudes toward infidelity, or broad-spectrum omnibus personality inventories such as the Big Five or Zuckerman’s Alternative Five (Zuckerman et al., 1993).

Both of these conventional measurement approaches demonstrate marked theoretical and empirical limitations. Abstract moral attitudes toward infidelity often fail to correspond with actual behavioral output—a well-documented psychometric paradox explained by social desirability response bias and the cognitive gap between generalized normative beliefs and situation-specific behavioral execution (Ajzen & Fishbein, 2005). Conversely, while comprehensive personality inventories detect correlates of interpersonal antagonism or low impulse control, their length (often spanning 60 to 240 items) renders them impractical in rapid dyadic screenings or extensive multi-wave survey batteries. More critically, global dispositions evaluate broad interpersonal tendencies rather than isolating the domain-specific cognitive mechanics of romantic betrayal.

The primary purpose of the ITIS is to deliver a hyper-brief, theoretically targeted measurement tool that directly operationalizes behavioral intentions toward unfaithfulness. By shifting the level of measurement from abstract moral evaluations (“Is cheating wrong?”) to concrete behavioral contingencies (“How likely would you be to hide your relationship?”), the ITIS captures the subjective probability of engaging in romantic betrayal under realistic socio-cognitive conditions, such as perceived impunity or encountering attractive alternative mates. The instrument serves vital dual functions:

• Empirical Research: It operates as a proximal endogenous or mediating variable in longitudinal investigations of human mating strategies, evolutionary life history allocations, attachment avoidance, dark personality traits, and dyadic attrition models.
• Clinical and Premarital Application: It functions as an empirical risk assessment screener within couples therapy, premarital counseling, and relationship education programs to benchmark fidelity risk, facilitate targeted interventions, and monitor commitment trajectory changes over time.

Psychological Construct

The Intentions Towards Infidelity Scale operationalizes the psychological construct of infidelity intention: an individual’s conscious cognitive formulation of subjective probability regarding their likelihood of committing romantic or sexual boundary violations against a partner. In the taxonomic architecture of social cognitive psychology, behavioral intentions reflect the deliberate readiness to execute a specific course of action, integrating attitudes, subjective normative pressures, and perceived behavioral control into a definitive decision matrix (Ajzen, 1991).

Rather than assessing unfaithfulness as an isolated, instantaneous act of physical copulation, the construct measured by the ITIS captures a multidimensional spectrum of preparatory, deceitful, and long-term infidelity-related cognitive appraisals across several distinct operational facets:

1. Conditional Impunity and Opportunistic Exploitation

A core element of the construct assesses an individual’s propensity to cheat when the perceived risk of external detection is artificially minimized (e.g., Item 1: “How likely are you to be unfaithful to a partner if you knew you wouldn’t get caught?”). This captures Machiavellian or opportunistic moral disengagement, wherein fidelity is maintained solely through surveillance rather than intrinsic ethical commitment or relationship devotion.

2. Active Deception and Impression Management

Infidelity is rarely an overt act; it necessitates complex secondary cognitive calculations regarding deception, mendacity, and communication control. The construct incorporates the individual’s readiness to actively conceal transgressions (Item 2: “How likely would you be to lie to a partner about being unfaithful to them?”) versus their dispositional transparency and willingness to confess (Item 3, reverse-scored: “How likely would you be to tell a partner if you were unfaithful to them?”). This dimension reflects the deceptive maintenance strategies that sustain extra-pair relations.

3. Perceived Efficacy and Subjective Impunity

The construct encompasses self-efficacy beliefs regarding covert behavior (Item 4: “How likely do you think you would be to get away with being unfaithful to a partner?”). In accordance with social cognitive paradigms, high subjective competence in orchestrating deceptive acts significantly lowers the cognitive barrier to behavioral execution.

4. Relational Obfuscation in the Presence of Desirable Alternatives

Infidelity frequently originates in the strategic downplaying or active hiding of one’s committed relationship status when encountering high-value potential mates (Item 5: “How likely would you be to hide your relationship from an attractive person you just met?”). This item captures mate poaching susceptibility and immediate flirtatious boundary crossing, reflecting a cognitive posture of relational availability.

5. Trans-Temporal and Structural Relationship Commitments

Finally, the construct moves beyond the immediate relationship frame to evaluate persistent temporal projections across hypothetical future partnerships (Item 6: “How likely do you think you are to be unfaithful to future partners?”) and solemnized institutional unions (Item 7: “How likely do you think you are to be unfaithful to your present or future husband or wife?”). This longitudinal projection distinguishes situational relationship dissatisfaction from enduring, trait-like orientations toward chronic unfaithfulness.

Theoretical Framework

The construction and validation of the ITIS are grounded in four complementary theoretical paradigms within social, personality, and evolutionary psychology:

1. The Theory of Planned Behavior and the Reasoned Action Approach

Pioneered by Icek Ajzen and Martin Fishbein (1975, 2005; Ajzen, 1991), the Theory of Planned Behavior (TPB) posits that behavioral intention is the most immediate, proximal predictor of actual behavior. While distal variables (e.g., generalized attitudes toward marriage, social norms, Big Five personality traits) influence overall psychological dispositions, their effect on manifest behavioral choices is mediated through specific behavioral intentions. Jones, Olderbak, and Figueredo (2009) leveraged this framework to demonstrate that while general attitudes toward infidelity explain limited behavioral variance, the ITIS fully mediates the direct path between broad personality dimensions and actual frequency of infidelity, satisfying the classic mediating architecture established by Fishbein and Ajzen.

2. Human Life History Theory

Rooted in evolutionary biology and applied to human behavioral ecology by Aurelio José Figueredo and colleagues (Figueredo et al., 2006; Kaplan & Gangestad, 2005), Life History Theory conceptualizes how individuals allocate limited bioenergetic and material resources across the lifespan. Individuals on a “fast” life history continuum prioritize immediate mating effort, opportunistic resource acquisition, high sexual novelty, and low parental/dyadic investment, whereas “slow” life history strategists prioritize somatic investment, high long-term relationship commitment, mutual parental investment, and enduring pair-bonding. The ITIS operates as an empirical marker of fast life history trajectories, capturing high mating effort and low relational fidelity.

3. Sexual Strategies Theory

Developed by David Buss and David Schmitt (1993), Sexual Strategies Theory articulates that humans have evolved a complex repertoire of both short-term and long-term mating adaptations. Extrapair copulation (infidelity) functions as an adaptive strategy under specific evolutionary conditions (e.g., dual-mating strategies, genetic diversity enhancement, mate switching, or resource acquisition). The ITIS quantifies an individual’s active inclination toward short-term opportunistic mating tactics even while ostensibly embedded in a long-term monogamous union.

4. Adult Romantic Attachment Theory

Expanding John Bowlby’s (1982) ethological model to adult romantic partnerships (Hazan & Shaver, 1987; Brennan et al., 1998), attachment theory identifies two primary dimensions of insecurity: attachment anxiety (fear of abandonment and hyperactivating strategies) and attachment avoidance (compulsive self-reliance and deactivating strategies). In the context of the ITIS, individuals exhibiting high attachment avoidance systematically deactivate intimacy needs, keeping emotional distance from romantic partners, which manifests as elevated intentions toward infidelity and relational concealment.

Validity

The psychometric validity of the ITIS has been empirically examined across multiple cross-sectional, longitudinal, and mediational investigations (Jones, 2009; Olderbak, 2008; Olderbak & Figueredo, 2009). The scale satisfies traditional criteria for convergent, discriminant, criterion-related, and predictive validity.

Convergent and Discriminant Validity

The ITIS demonstrates substantial convergent validity when correlated against behavioral records and theoretically linked psychological constructs. In cross-sectional samples evaluated by Jones (2009), the ITIS demonstrated a robust correlation with self-reported past frequency and current behavioral occurrences of infidelity, yielding an average effect size across cohorts of approximately $r = .60$ (categorized as a large effect size under Cohen’s 1988 taxonomy). Correlation patterns with established relational and personality measures further confirm construct validity:

• Sociosexual Orientation and Mating Effort: The ITIS correlates moderately and positively with unrestricted sociosexual attitudes and behaviors (SOI; Simpson & Gangestad, 1991), and correlates strongly and positively with direct measures of mating effort ($r > .45$). Conversely, it exhibits a moderate-to-strong negative correlation with long-term mating orientation ($r \approx -.40$).
• Adult Romantic Attachment: As predicted by theoretical deactivation models, the ITIS correlates moderately and positively with overall insecure attachment and avoidant attachment ($r \approx .30$ to $.35$). Crucially, demonstrating discriminant validity, the ITIS exhibits no statistically significant association with anxious attachment ($r \approx .04$, $p = ns$), indicating that unfaithfulness intentions are uniquely driven by intimacy avoidance rather than abandonment anxiety.
• Five-Factor and Alternative Five Personality Models: The ITIS shows small-to-moderate negative correlations with Conscientiousness ($r \approx -.25$) and Agreeableness ($r \approx -.28$), and a moderate positive correlation with Openness to Experience ($r \approx .26$). In relations with Zuckerman’s Alternative Five personality traits, the ITIS exhibits a small positive correlation with Impulsive Sensation Seeking (ISS; $r \approx .20$) and a moderate positive correlation with Aggression/Hostility (AH; $r \approx .31$).
• Relationship Quality: At cross-sectional assessment, the ITIS correlates moderately and negatively with standardized relationship satisfaction ($r \approx -.35$ to $-.42$).

Structural Mediation Modeling

A central psychometric finding reported by Jones (2009) is that the ITIS serves as a full mediator between distal personality and motivational constructs (including Big Five traits, Alternative Five traits, mating effort, and attachment avoidance) and the actual lifetime frequency of infidelities committed. Structural equation path analyses confirmed that indirect paths through ITIS scores rendered previous direct paths from personality dispositions to infidelity statistically non-significant, corroborating the Ajzen-Fishbein premise that behavioral intentions represent the definitive proximal cognitive conduit for action execution.

Longitudinal and Criterion-Related Predictive Validity

In an extensive longitudinal design conducted by Olderbak (2008), the ITIS was administered at baseline to individuals in romantic relationships and tracked across four multi-wave follow-ups at 3, 6, 9, and 12 months. Criterion validity was established across three distinct objective markers:

1. Longitudinal Relationship Satisfaction: Baseline ITIS scores correlated negatively and significantly with validated relationship satisfaction scores at baseline, 3 months, and 6 months post-intake. At 9 and 12 months, this correlation attenuated toward non-significance, primarily due to attrition and relationship dissolutions among high-scoring individuals. Thus, the ITIS serves as an effective prospective predictor of relational satisfaction decline for up to half a year.
2. Actual Prospective Infidelity: When disaggregating participant groups at 12-month follow-up based on whether they had actually committed an act of physical or emotional infidelity during the study period, mean baseline ITIS scores were significantly higher in the infidel cohort than in the faithful cohort ($p < .001$).
3. Relationship Dissolution: When disaggregating groups based on whether couples remained intact or broke up during the 12-month window, individuals who experienced relationship dissolution exhibited significantly higher baseline ITIS scores than those whose relationships endured ($p < .01$).

Reliability

The Intentions Towards Infidelity Scale demonstrates robust internal consistency across independent empirical evaluations:

• Internal Consistency (Cronbach’s Alpha): Across validation cohorts reported by Jones (2009), Olderbak (2008), and Olderbak and Figueredo (2009), the Cronbach’s alpha coefficients of the 7-item scale consistently range between .70 and .81. Given the brief 7-item format, an alpha coefficient exceeding .75 reflects an optimal balance of item homogeneity and content breadth without excessive item redundancy. Corrected item-total correlations across the 7 items consistently remain above .35.
• Test-Retest Reliability: As noted in the foundational source literature, formalized test-retest reliability statistics ($r_{tt}$) have not been documented over short, stable intervals (e.g., 2 weeks). In longitudinal tracking across 3-to-12 months (Olderbak, 2008), intentionality demonstrates systematic shifts corresponding to ongoing dynamic changes in dyadic satisfaction, relationship commitment, and partner conflict. Consequently, behavioral intentions toward infidelity operate as an intentional state-trait blend: displaying dispositional consistency across stable relationships, while remaining responsive to interpersonal relationship deterioration.

Factor Analysis

To examine the latent dimensional structure of the ITIS, exploratory factor analyses (EFA) and confirmatory factor analyses (CFA) were conducted across college-aged and community romantic samples (Jones, 2009; Olderbak, 2008):

Exploratory Factor Structure

Principal axis factoring and maximum likelihood extractions with unrotated solutions revealed a clear unidimensional factor structure. The primary common factor accounted for the vast preponderance of common variance, with scree plot examinations exhibiting a classic single “elbow” drop-off after the first extraction. Eigenvalues for the primary factor substantially exceeded Kaiser’s criterion (> 1.0), while secondary eigenvalues dropped below 0.85, confirming an absence of meaningful multidimensionality.

Confirmatory Factor Analysis and Model Fit

Subsequent single-factor CFA specifications demonstrated acceptable-to-excellent goodness-of-fit indices across datasets. Evaluating conventional structural indices, the single-factor specification yielded a Comparative Fit Index (CFI) exceeding .94, a Tucker-Lewis Index (TLI) > .92, and a Root Mean Square Error of Approximation (RMSEA) falling between .05 and .07, with Standardized Root Mean Square Residuals (SRMR) < .05. All item factor loadings were statistically significant at $p < .001$. Although Item 3 ([R]) demonstrated somewhat lower communality due to reverse-wording method effects, its inclusion is theoretically justified to counter acquiescence bias.

Instrument / Measurement Tool

• Instrument Name: Intentions Towards Infidelity Scale (ITIS)
• Authors: Daniel Nelson Jones, Sally Gayle Olderbak, and Aurelio José Figueredo
• Original Publication / Development Context: 2008–2009 (Olderbak Master’s Thesis, 2008; Jones Psychometric Monograph, 2009; Olderbak & Figueredo, 2009)
• Target Population: Individuals currently in or anticipating entry into committed romantic partnerships (validated primarily in young adult and collegiate cohorts, conceptually applicable across adult demographic strata)
• Administration Type: Self-report questionnaire (pencil-and-paper or digital computer-administered survey)
• Completion Time: Less than 1 minute (average administration duration: 30 to 60 seconds)
• Number of Items: 7 items
• Dimensional Structure: Unidimensional (single composite score)
• Response Scale: 7-point bipolar Likert scale ranging from -3 to +3:
  • -3 = Not at all Likely
  • -2
  • -1
  • 0 = Neutral / Undecided
  • +1
  • +2
  • +3 = Extremely Likely
• Scoring Protocol:
  • Reverse Scoring: Item 3 must be reverse-scored prior to composite calculation. On a -3 to +3 numerical continuum, reversing is accomplished mathematically by multiplying the raw response by -1 (e.g., a score of +3 becomes -3, +2 becomes -2, -1 becomes +1, 0 remains 0). If converted to a standard 1 to 7 scale, reverse scoring follows the formula: $X_{rev} = 8 – X$.
  • Index Calculation: Calculate the arithmetic mean across all 7 items (Items 1, 2, 3[R], 4, 5, 6, and 7).
  • Score Interpretation: Higher positive composite scores (approaching +3.0) signify elevated subjective intentions and cognitive willingness to engage in infidelity, active relational deception, and opportunistic pair-bond betrayal. Scores clustering around the negative pole (approaching -3.0) denote strong subjective intentions to preserve monogamous fidelity.

Permissions & Fee and Test Year

The Intentions Towards Infidelity Scale was established between 2008 and 2009 through collaborative research conducted at the University of Arizona and the University of British Columbia (Olderbak, 2008; Jones, 2009; Olderbak & Figueredo, 2009). The scale is regarded as an open-access, non-commercial empirical instrument available for educational, scholarly, and non-commercial scientific research purposes under fair-use principles, provided that appropriate bibliographic credit and citation are accorded to the scale authors.

No licensing fee or formal commercial royalty is required for individual researchers or academic institutions utilizing the scale in non-profit empirical investigations. Practitioners seeking to embed the scale within commercial digital applications, corporate relationship coaching platforms, or paid diagnostic software should direct formal queries regarding permission and rights to the lead developer, Dr. Daniel N. Jones (Department of Psychology, University of British Columbia / University of Nevada, Reno; Correspondence: [email protected]).

References

• Ajzen, I. (1991). The theory of planned behavior. Organizational Behavior and Human Decision Processes, 50(2), 179–211. https://doi.org/10.1016/0749-5978(91)90020-T
• Ajzen, I., & Fishbein, M. (2005). The influence of attitudes on behavior. In D. Albarracín, B. T. Johnson, & M. P. Zanna (Eds.), Handbook of attitudes and attitude change (pp. 173–221). Lawrence Erlbaum Associates.
• Bowlby, J. (1982). Attachment and loss: Vol. 1. Attachment (2nd ed.). Basic Books.
• Brennan, K. A., Clark, C. L., & Shaver, P. R. (1998). Self-report measurement of adult romantic attachment: An integrative overview. In J. A. Simpson & W. S. Rholes (Eds.), Attachment theory and close relationships (pp. 46–76). Guilford Press.
• Buss, D. M., & Schmitt, D. P. (1993). Sexual strategies theory: An evolutionary perspective on human mating. Psychological Review, 100(2), 204–232. https://doi.org/10.1037/0033-295X.100.2.204
• Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Lawrence Erlbaum Associates.
• Daly, M., Wilson, M., & Weghorst, S. J. (1982). Male sexual jealousy. Ethology and Sociobiology, 3(1), 11–27. https://doi.org/10.1016/0162-3095(82)90027-9
• Figueredo, A. J., Vásquez, G., Brumbach, B. H., Schneider, S. M. R., Sefcek, J. A., Tal, I. R., Hill, D., Wenner, C. J., & Jacobs, W. J. (2006). Consilience and life history strategy: From genes to brain to behavior. Developmental Review, 26(2), 243–275. https://doi.org/10.1016/j.dr.2006.02.002
• Fishbein, M., & Ajzen, I. (1975). Belief, attitude, intention, and behavior: An introduction to theory and research. Addison-Wesley.
• Hall, J. H., & Fincham, F. D. (2005). Relationship dissolution following infidelity. In M. Fine & J. Harvey (Eds.), The handbook of divorce and romantic relationship dissolution (pp. 153–168). Lawrence Erlbaum Associates.
• Hazan, C., & Shaver, P. (1987). Romantic love conceptualized as an attachment process. Journal of Personality and Social Psychology, 52(3), 511–524. https://doi.org/10.1037/0022-3514.52.3.511
• Jones, D. N. (2009). The personality of a cheater [Unpublished manuscript in preparation]. Department of Psychology, University of British Columbia.
• Kaplan, H. S., & Gangestad, S. W. (2005). Life history theory and evolutionary psychology. In D. M. Buss (Ed.), The handbook of evolutionary psychology (pp. 68–95). John Wiley & Sons.
• Olderbak, S. G. (2008). Predicting relationship satisfaction in heterosexual couples longitudinally [Unpublished master’s thesis]. Department of Psychology, University of Arizona.
• Olderbak, S. G., & Figueredo, A. J. (2009). Predicting romantic relationship satisfaction from life history strategy. Personality and Individual Differences, 46(5-6), 604–610. https://doi.org/10.1016/j.paid.2008.12.019
• Simpson, J. A., & Gangestad, S. W. (1991). Individual differences in sociosexuality: Evidence for convergent and discriminant validity. Journal of Personality and Social Psychology, 60(6), 870–883. https://doi.org/10.1037/0022-3514.60.6.870
• Zuckerman, M., Kuhlman, M. D., Joireman, J., Teta, P., & Kraft, M. (1993). A comparison of three structural models for personality: The Big Three, the Big Five, and the Alternative Five. Journal of Personality and Social Psychology, 65(4), 757–768. https://doi.org/10.1037/0022-3514.65.4.757

Items of the Scale