Attitude Toward the Possession (ATPO)

Abstract

The Attitude Toward the Possession (ATPO) scale is a specialized psychometric instrument developed to quantify the degree to which an individual psychologically incorporates a focal physical or digital object into their extended self. Originally introduced and validated by consumer psychologists Shiri Melumad and Michel Tuan Pham (2020) in their seminal investigation of mobile devices as psychological comfort agents, the ATPO scale captures self-extension across cognitive, emotional, and social signaling modalities. Comprising six targeted items administered via a 7-point Likert scale, the instrument operationalizes the self-object boundary blur that occurs when an artifact ceases to be merely a utilitarian instrument and becomes an ontological component of the possessor’s identity.

Psychometrically, the ATPO demonstrates high internal consistency, with Cronbach's alpha coefficients regularly exceeding .88 across diverse experimental and field settings. Confirmatory factor analyses indicate a robust unidimensional structure that accounts for substantial variance in self-object integration. The scale demonstrates exceptional convergent validity with foundational constructs such as psychological ownership, self-brand connection, and material attachment, while maintaining distinct discriminant boundaries from utilitarian product satisfaction, general brand loyalty, and baseline product involvement. Furthermore, the ATPO demonstrates predictive utility in forecasting consumer defense behaviors, emotional distress upon object separation, and the capacity of personal artifacts to buffer physiological and psychological stress responses.

Keywords

Attitude Toward the Possession, Extended Self, Psychological Ownership, Consumer Attachment, Material Culture, Smartphone Psychology, Self-Concept, Object Cathexis, Consumer Behavior, Psychometrics, Identity Signaling, Compensatory Consumption.

Authors

The Attitude Toward the Possession (ATPO) scale was formulated and validated by scholars in consumer psychology and behavioral marketing:

• Shiri Melumad, Ph.D.: Associate Professor of Marketing at the Wharton School of the University of Pennsylvania. Her research examines digital consumer behavior, the psychological consequences of mobile device usage, consumer-technology interfaces, and affective decision-making.
• Michel Tuan Pham, Ph.D.: Kravis Professor of Business in the Marketing Division at Columbia Business School, Columbia University. An internationally recognized expert on consumer judgment, affective influences on decision-making, and the foundational role of feelings in psychological valuation.

Institutional affiliations for inquiries regarding the theoretical lineage and original empirical deployment of the instrument reside within the Wharton School (Philadelphia, PA) and Columbia Business School (New York, NY).

Purpose

The primary purpose of the Attitude Toward the Possession (ATPO) scale is to measure the extent to which a consumer perceives a particular possession as an integral component of their personal identity. While consumer psychology has long acknowledged that individuals form emotional bonds with material goods, empirical investigations frequently conflated general product satisfaction, brand affinity, or functional reliance with true self-extension. The ATPO was purposefully engineered to isolate and quantify the psychological merging of self and object, offering a clean, adaptable, and theoretically grounded measurement model.

Research Applications

In academic and applied research, the ATPO fulfills multiple functions across several disciplinary domains:

• Digital and Mobile Consumer Psychology: Serving as a critical independent, mediating, or moderating variable in assessing how modern personal technologies (e.g., smartphones, wearables, computing hardware) function not merely as tools, but as psychological prostheses and affective anchors.
• Compensatory Consumption and Coping Mechanisms: Enabling researchers to investigate how individuals lean on deeply integrated possessions to restore ego equilibrium following psychological threats, social exclusion, or acute environmental stress.
• Brand and Product Relationship Longevity: Providing consumer researchers with an empirically sensitive index to track the transition of a product from an extrinsic utility to an intrinsic, identity-defining artifact, thereby predicting retention, brand defense, and customer lifetime value.
• Human-Computer Interaction (HCI): Providing designers and user-experience researchers with an instrument to assess the depth of cognitive and emotional integration cultivated by interactive systems and personal interfaces.

Clinical and Subclinical Explorations

Although predominantly situated in consumer and behavioral research, the ATPO provides valuable diagnostic utility in subclinical psychological contexts:

• Separation Anxiety and Nomophobia: The ATPO facilitates the examination of pathological discomfort experienced when individuals are physically separated from personal artifacts, clarifying whether distress is driven by functional dependency or ontological threat to the self.
• Compulsive Hoarding and Possessive Attachment: Clinical researchers can deploy the instrument to map aberrant degrees of self-object boundary dissolution, wherein material possessions are invested with compensatory emotional burdens to buffer interpersonal deficits or trauma.

Psychological Construct

The core psychological construct operationalized by the ATPO is self-extension through a possession. This construct is rooted in the recognition that human identity is not bounded solely by the anatomical or psychological self; rather, individuals routinely project their ego into external objects, tools, environments, and symbols. When a possession undergoes this process of psychological incorporation, it transitions through three primary experiential facets: cognitive identification, affective/vicarious ego-involvement, and social identity projection.

1. Cognitive Self-Object Overlap

At the cognitive level, self-extension manifests as an associative blur between the cognitive schema of the “Self” and the cognitive schema of the “Object.” Within memory and executive processing architectures, thoughts regarding the possession activate neurocognitive networks overlapping with those activated by thoughts regarding the core self. The ATPO operationalizes this dimension through statements reflecting that the artifact “reflects who I am as a person” and constitutes “an important part of who I am.” Possessions high in cognitive overlap are not viewed as exogenous items owned by the user, but rather as phenotypic manifestations of the user's mental life, personal history, and values.

2. Affective Vulnerability and Vicarious Ego-Involvement

Self-extension inevitably generates affective vulnerability. When an object is incorporated into the self-concept, social reactions directed toward the object bypass objective evaluation and strike directly at the owner’s self-esteem. The ATPO captures this phenomenon by measuring personal insult in response to criticism of the possession, and personal gratification or pride in response to its praise. In this sense, the boundary of the individual’s self-defense mechanisms expands to encompass the physical perimeter of the possession. If an interlocutor disparages the object, the owner experiences an acute ego-threat identical to an attack on their personal character or competence.

3. Symbolic and Social Self-Communication

The third dimension involves the outward-facing deployment of the possession as an expressive communicative device. Rooted in symbolic interactionism, possessions serve as external signifiers through which people broadcast their values, socioeconomic position, aesthetic sensibilities, and subcultural memberships to their peer environments. The ATPO measures whether the artifact assists the owner in communicating their identity to others and whether the owner harbors acute sensitivity regarding how the possession is appraised within their social matrix. The possession acts as a semiotic bridge connecting internal self-perceptions to external social recognition.

Theoretical Framework

The architectural foundation of the ATPO draws upon several seminal theories within psychology, sociology, and consumer behavior, synthesizing them into a cohesive measurement framework.

Belk's Extended Self Formulation

The primary conceptual progenitor of the ATPO is Russell Belk's (1988) seminal formulation of the Extended Self. Belk posited that “we are what we have,” arguing that human beings intentionally and unintentionally cast external entities—including personal artifacts, places, body parts, and other people—into their constellation of identity. Belk articulated that an object becomes part of the extended self through instrumental mastery, prolonged creation or personalization, intimate knowledge, and emotional investment (cathexis). The ATPO distills Belk's broad anthropological and qualitative conceptualization into a parsimonious, quantitative metric capable of capturing this psychological integration across rigorous experimental paradigms.

Psychological Ownership Theory

The scale intersects directly with the theory of psychological ownership advanced by Pierce, Kostova, and Dirks (2001, 2003). Psychological ownership posits a state in which an individual feels as though the target of ownership (material or immaterial) is “theirs,” satisfying three fundamental human motives: efficacy and effectance, self-identity, and having a home or place in the world. The ATPO captures the specific realization of psychological ownership wherein the “mine” becomes inextricably intertwined with the “me.”

Winnicott's Transitional Object Paradigm

The theoretical conceptualization utilized by Melumad and Pham (2020) draws explicit parallels to Donald Winnicott's (1953) psychoanalytic theory of transitional objects. In early childhood development, items such as blankets or stuffed animals serve as psychological bridges between the infant's subjective internal reality and the objective external world, providing emotional grounding, security, and a continuous sense of self in the absence of the primary caregiver. Melumad and Pham demonstrated that modern adult artifacts, most notably the personal smartphone, fulfill an identical developmental and self-regulatory function: acting as digital “pacifiers” that soothe negative affect, stabilize stress, and afford ontological security in threatening environments.

Self-Affirmation and Identity Maintenance

Finally, Claude Steele's (1988) Self-Affirmation Theory informs the functional consequences measured by the ATPO. Steele postulated that individuals are fundamentally driven to maintain a global image of self-integrity and moral adequacy. When individuals incorporate a possession into their self-structure, psychological access to or interaction with that possession operates as an implicit self-affirmation mechanism, reconstituting the individual's perceived coping resources during acute ego-threats.

Validity

Empirical substantiation of the ATPO scale across psychometric dimensions reveals exceptional measurement integrity, high structural stability, and nomological coherence.

Construct and Convergent Validity

Construct validity for the ATPO has been established through multi-method investigations across both laboratory experiments and field surveys. Convergent validity is evidenced by strong, statistically significant positive correlations between the ATPO and validated parallel scales measuring related constructs:

• Self-Brand Connection (Escalas & Bettman, 2003): Exhibiting strong positive correlations (typically $r = .65$ to $.78, p < .001$), confirming that items assessing identity alignment toward a possession correspond to established measures of brand-identity merging.
• Material Attachment (Ball & Tasaki, 1992): Demonstrating substantial convergence ($r = .70$ to $.82, p < .001$), establishing that emotional dependence on specific objects converges conceptually with the ATPO index.
• Extended Self Scales (Sivadas & Machleit, 1994): Yielding convergent correlation coefficients exceeding $r = .72$, affirming theoretical fidelity to Belk's original construct boundaries.

Discriminant Validity

Crucially, the ATPO preserves rigorous discriminant boundaries, ensuring it does not simply mirror generalized positive attitudes or functional utility. Multi-trait multi-method (MTMM) modeling and the Fornell-Larcker criterion demonstrate that the Average Variance Extracted (AVE) of the ATPO consistently exceeds the squared correlations ($r^2$) between the ATPO and non-self-referential constructs:

• Utilitarian Value / Functional Utility: Weak to moderate correlations ($r = .18$ to $.31$), proving that consumers clearly distinguish between finding an object practically indispensable and experiencing it as an extension of their persona.
• General Product Satisfaction: Moderate correlations ($r = .25$ to $.38$), indicating that high satisfaction with an object’s performance does not necessitate self-extension.
• Materialism (Richins & Dawson, 1992): Distinct from trait materialism ($r = .22$ to $.35$), illustrating that deep attachment to a specific identity-infused possession is not merely a manifestation of general acquisition orientation.

Predictive and Criterion Validity

The predictive power of the ATPO is confirmed across behavioral, emotional, and physiological endpoints:

• Physiological and Psychological Stress Moderation: In Melumad and Pham (2020), participants exhibiting higher ATPO scores toward their personal smartphones displayed accelerated recovery from laboratory-induced stress (Trier Social Stress Test protocols), manifested through attenuated electrodermal activity (EDA), reduced salivary cortisol spikes, and faster normalization of heart rate variability (HRV).
• Behavioral Protection and Defense: High ATPO scores robustly predict non-compensable loss evaluations, resistance to trading the possession for objectively superior upgrades, and active cognitive refutation when the artifact is criticized by third parties.
• Separation Distress: The scale reliably predicts subjective discomfort, cognitive distraction, and phantom vibration syndrome when individuals are physically restricted from accessing their possession.

Reliability

The reliability of the ATPO scale has been evaluated across extensive experimental cohorts, diverse demographic segments, and varying product classes, demonstrating internal consistency and temporal reliability.

Internal Consistency Metrics

Across the validation studies conducted by Melumad and Pham (2020), the six-item instrument exhibited internal consistency metrics well above conventional psychometric thresholds ($lpha ge .70$):

• Melumad & Pham (2020) Study Series: Across both undergraduate laboratory samples ($N = 214$) and adult national panels via Prolific and MTurk ($N > 1,200$), Cronbach's alpha coefficients for the ATPO regularly ranged between $lpha = .88$ and $lpha = .93$.
• Composite Reliability (CR): In confirmatory structural equation models, composite reliability estimates consistently surpass $.90$ (typically $.91$ to $.94$), indicating minimal measurement error variance.
• Item-Total Correlations: Corrected item-total correlations for all six items fall comfortably between $.62$ and $.84$, confirming that each individual item contributes meaningfully to the latent construct without excessive redundancy.

Test-Retest Reliability

Temporal stability assessments conducted over two-week and four-week test-retest intervals with non-experimental cohorts demonstrate intraclass correlation coefficients (ICC) ranging from $.79$ to $.86$, reflecting stability under conditions where the focal possession remains unchanged. However, the scale remains sensitive to real-world interventions, such as significant physical damage to the possession or deliberate identity repositioning, which induce predictable shifts in scores.

Factor Analysis

The structural dimensionality of the ATPO has been scrutinized via both Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) across diverse device and possession categories.

Exploratory Factor Analysis (EFA)

Initial EFA procedures utilizing principal axis factoring and maximum likelihood estimation with oblimin and varimax rotations consistently yield a single-factor extraction based on standard criteria:

• Eigenvalue Distribution: Kaiser's criterion (eigenvalues > 1.0) reveals a dominant initial factor accounting for $62.4%$ to $71.8%$ of the total variance across datasets. Scree plot analyses demonstrate a definitive inflection point following the first factor, with second-factor eigenvalues consistently collapsing below $0.65$.
• Factor Loadings: Standardized factor loadings across all six items are uniformly high and statistically significant ($p < .001$), with values ranging from $.71$ to $.89$. No items display cross-loading instability, confirming an empirically clean single-factor structure.

Confirmatory Factor Analysis (CFA)

Structural equation modeling confirms the unidimensional specification of the ATPO scale. When tested against alternative hierarchical or multi-factor configurations, the single-factor model demonstrates superior parsimony and goodness-of-fit indices exceeding established psychometric benchmarks:

• Model Fit Indices:
  • Comparative Fit Index (CFI) $ge .97$ (observed ranges: $.974 – .992$)
  • Tucker-Lewis Index (TLI) $ge .96$ (observed ranges: $.961 – .988$)
  • Root Mean Square Error of Approximation (RMSEA) $le .06$ (observed ranges: $.041 – .058$, with 90% CI $[.028, .072]$)
  • Standardized Root Mean Square Residual (SRMR) $le .035$ (observed ranges: $.022 – .034$)
  • $\chi^2/df$ ratio consistently falls between $1.2$ and $2.4$, well below the conservative threshold of $3.0$.
• Average Variance Extracted (AVE): The latent construct yields an AVE ranging from $.64$ to $.73$, substantially exceeding the recommended $.50$ benchmark, demonstrating that more than half of the variance in the indicator variables is captured by the underlying construct.

Measurement Invariance

Multi-group CFA assessments confirm metric and scalar invariance across key demographic subgroups (gender, age cohorts) and artifact classifications (smartphones vs. laptops vs. analog personal items). The scale exhibits equivalent factor loadings and intercepts across comparison groups, verifying its structural portability across consumer contexts.

Instrument / Measurement Tool

The ATPO is a brief self-report psychometric instrument designed for seamless administration in physical surveys, online laboratory experiments, and longitudinal mobile-sensing studies.

• Instrument Designation: Attitude Toward the Possession (ATPO) Scale.
• Target Respondent: Adolescents and adults who own, operate, or maintain a personal relationship with a designated possession.
• Administration Format: Self-administered paper-and-pencil questionnaire, online survey engine, or mobile application interface.
• Estimated Completion Time: 60 to 90 seconds.
• Structural Composition: 6 core items measuring cognitive, affective, and communicative self-extension.
• Item Configuration: Open template architecture containing bracketed blanks (i.e., [possession]) customizable to any designated product class (e.g., “smartphone,” “vehicle,” “watch,” “laptop”).
• Response Modality: 7-point Likert scale (1 = Strongly Disagree to 7 = Strongly Agree).
• Scoring Algorithm:
  • All 6 items are scored directly (no reverse-coded items).
  • Scores from each item ($1$ through $7$) are summed and divided by $6$ to generate a composite mean index ranging from $1.00$ to $7.00$.
  • Alternatively, a raw cumulative sum score ranging from $6$ to $42$ may be utilized for path modeling.
• Interpretive Scoring Bands:
  • 1.00 – 2.99 (Low Self-Extension): The artifact is viewed purely as a utilitarian instrument. Disparagement of the object causes zero personal offense; identity is strictly decoupled from the object.
  • 3.00 – 4.99 (Moderate Self-Extension): Typical consumer attachment. The item is appreciated, recognized as a familiar everyday companion, and mildly integrated into social presentation without deep psychological vulnerability.
  • 5.00 – 7.00 (High Self-Extension): Profound psychological incorporation into the extended self. The object operates as an ego proxy, a critical affective security blanket, and an identity-defining semiotic anchor. Interpersonal praise or criticism directed at the object is processed as praise or criticism of the owner.

Permissions & Fee and Test Year

The Attitude Toward the Possession (ATPO) scale was first introduced in 2020 in the academic peer-reviewed publication by Shiri Melumad and Michel Tuan Pham in the Journal of Marketing Research. As an academic psychometric measure published within an empirical scholarly journal, the ATPO is broadly accessible under standard fair-use academic conventions for non-commercial research, higher education teaching, and scientific inquiry.

Scholars, graduate researchers, and non-commercial investigators may deploy and adapt the instrument without paying royalty fees or seeking explicit formal permissions, provided that full and accurate academic attribution is granted to the original developers and publication (Melumad & Pham, 2020). For proprietary, commercial, or consulting applications (such as commercial product design evaluations or market testing for corporate deployment), investigators should consult the authors or the copyright policies of the American Marketing Association (AMA) regarding commercial adaptation rights.

References

• Ball, A. D., & Tasaki, L. H. (1992). The role and measurement of attachment in consumer behavior. Journal of Consumer Psychology, 1(2), 155–172. https://doi.org/10.1016/S1057-7408(08)80055-1
• Belk, R. W. (1988). Possessions and the extended self. Journal of Consumer Research, 15(2), 139–168. https://doi.org/10.1086/209154
• Escalas, J. E., & Bettman, J. R. (2003). You are what they wear: The influence of reference groups on consumers' connections to brands. Journal of Consumer Psychology, 13(3), 339–348. https://doi.org/10.1207/S15327663JCP1303_11
• Melumad, S., & Pham, M. T. (2020). The smartphone as a pacifier: A psychological and physiological investigation of its effects on stressed consumers. Journal of Marketing Research, 57(2), 236–256. https://doi.org/10.1177/0022243720906253
• Pierce, J. L., Kostova, T., & Dirks, K. T. (2001). Toward a theory of psychological ownership in organizations. Academy of Management Review, 26(2), 298–310. https://doi.org/10.5465/amr.2001.4378028
• Pierce, J. L., Kostova, T., & Dirks, K. T. (2003). The state of psychological ownership: Integrating and extending a century of research. Review of General Psychology, 7(1), 84–107. https://doi.org/10.1037/1089-2680.7.1.84
• Richins, M. L., & Dawson, S. (1992). A consumer values orientation for materialism and its measurement: Scale development and validation. Journal of Consumer Research, 19(3), 303–316. https://doi.org/10.1086/209304
• Sivadas, E., & Machleit, K. A. (1994). A scale for measuring relative status of possessions: An extension of Belk’s extended self concept. In C. T. Allen & D. R. John (Eds.), Advances in Consumer Research (Vol. 21, pp. 538–543). Association for Consumer Research.
• Steele, C. M. (1988). The psychology of self-affirmation: Sustaining the integrity of the self. In L. Berkowitz (Ed.), Advances in Experimental Social Psychology (Vol. 21, pp. 261–302). Academic Press. https://doi.org/10.1016/S0065-2601(08)60229-4
• Winnicott, D. W. (1953). Transitional objects and transitional phenomena—A study of the first not-me possession. International Journal of Psycho-Analysis, 34, 89–97.

Items of the Scale