Naturalness of the Food

1. Abstract

The Naturalness of the Food scale is a concise, highly targeted psychometric instrument designed to evaluate consumer perceptions of food items along the conceptual spectrum of naturalness, purity, and processing degree. Originally introduced by consumer psychologist Linda Hagen in her seminal 2021 investigation published in the Journal of Marketing, the instrument was formulated to dissect the cognitive mechanisms underpinning the “pretty equals healthy” heuristic. Specifically, the scale quantifies how subtle visual design cues—such as visual symmetry, harmonic order, and classical aesthetic presentation—lead consumers to infer that a food item possesses intrinsic organic qualities. Comprising three core descriptor items evaluated along bipolar semantic or Likert-type response formats (typically anchored from 1 = “Not at all” to 7 = “Extremely”), the instrument captures three semantic facets: how natural, pure, and unprocessed a food product is perceived to be.

Psychometrically, the scale operates as a unidimensional latent construct demonstrating robust internal consistency across diverse experimental samples, consistently yielding Cronbach’s alpha coefficients exceeding α = .88 (frequently spanning .89 to .94 across varying food categories, including fresh produce, baked confections, and composite prepared meals). Confirmatory factor analyses corroborate a single-factor configuration exhibiting high standardized factor loadings (λ > .85) and optimal model fit statistics. The scale exhibits pronounced convergent validity with multi-item nutritional health assessments and objective processing classification frameworks (such as the NOVA food classification system), while demonstrating robust discriminant validity against general aesthetic liking, visual valence, and caloric density perceptions. Furthermore, the instrument displays potent predictive and mediating validity, reliably accounting for substantial indirect variance in perceived healthiness, willingness to pay, and permissible consumption volume. Given the modern food landscape’s proliferation of aesthetic marketing, clean labeling, and green packaging, the Naturalness of the Food scale represents an indispensable empirical instrument for marketing researchers, sensory scientists, consumer psychologists, and public health policy analysts examining consumer food evaluation, cognitive biases, and dietary decision-making.

2. Keywords

Food Psychology, Perceived Naturalness, Food Aesthetics, Health Halo Effect, Consumer Behavior, Clean Labeling, Psychometrics, Sensory Marketing, Nutritional Heuristics, Structural Equation Modeling, Visual Design, Hagen (2021)

3. Authors

The scale was developed and psychometrically validated by:

• Linda Hagen, Ph.D.
  Associate Professor of Marketing
  Marshall School of Business, University of Southern California (USC)
  Los Angeles, California, United States
  Research Specialization: Consumer Psychology, Food Decision Making, Visual Perception, Cognitive Biases in Health Judgments, and Aesthetic Valuation.
  Contact & Institutional Profile: Marshall School of Business, Department of Marketing, 701 Exposition Blvd, Los Angeles, CA 90089.

4. Purpose

The primary objective of the Naturalness of the Food scale is to provide a parsimonious, psychometrically rigorous, and experimentally sensitive measurement of an individual’s subjective assessment of a food product’s natural state. In contemporary food marketing, consumer judgment rarely relies solely on chemical composition or standardized nutritional fact panels. Instead, human dietary choices are profoundly governed by heuristic evaluations rooted in sensory presentation, packaging design, and visual rhetoric. Hagen (2021) designed this instrument to isolate the critical psychological mediator operating between superficial visual aesthetics and consequential nutritional assumptions.

Theoretical and Practical Rationale

A longstanding conundrum within consumer behavior and public health is why individuals systematically misestimate the nutritional qualities of processed foods when presented in aesthetically pleasing forms. Hagen demonstrated that classical aesthetic principles—most notably visual symmetry, organic balance, and harmonic proportion—subconsciously cue evolutionary associations with healthy, flourishing natural organisms. The Naturalness of the Food scale was explicitly created to empirically measure whether an observer, upon viewing an artistically arranged or symmetrically plated dish (e.g., an intricately arranged avocado toast or a geometric arrangement of cupcakes), activates an implicit inference that the food has remained untouched by artificial processing or synthetic adulteration.

By measuring the perceived naturalness of the food directly, investigators can differentiate between two competing explanations for consumer bias: a generalized positive affect (“halo effect”) versus a specific semantic inference concerning biological authenticity. Hagen’s findings indicated that visual beauty does not simply make consumers “like” the food more; rather, it activates a specialized cognitive belief that the food is authentic, pure, and minimally engineered. The purpose of the scale is therefore both diagnostic and explanatory, serving to parse whether visual design characteristics alter consumer appraisals of a product’s intrinsic physical essence.

Research and Clinical Applications

Beyond academic consumer psychology, the scale occupies an essential role across several applied behavioral and empirical research domains:

• Public Health and Nutritional Epidemiology: Investigators deploy the scale to evaluate how deceptive front-of-package (FOP) graphic designs, pastoral imagery, and rustic typography induce a false sense of naturalness in energy-dense, nutrient-poor foods. This informs regulatory standards by agencies such as the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA).
• Sensory and Experimental Marketing: Retailers and consumer packaged goods (CPG) firms utilize the instrument during concept testing to determine whether variations in packaging material (e.g., matte versus glossy finishes, kraft paper textures, transparent windows) successfully communicate genuine agricultural origin without triggering skepticism.
• Clinical and Behavioral Nutrition: Behavioral clinicians studying eating disorders, orthorexia nervosa, and obesity utilize the scale to examine how maladaptive cognitive fixations on “clean” or “pure” foods distort risk perceptions and food consumption quantities among clinical populations.

5. Psychological Construct

The construct captured by the instrument is Perceived Food Naturalness (PFN). In the psychometric taxonomy of consumer psychology, perceived naturalness is defined as a multi-attribute cognitive appraisal reflecting the extent to which a food item is believed to have originated directly from nature and remained free from anthropogenic transformation, synthetic chemical intervention, or industrial modification. Rather than reflecting an objective biochemical metric, perceived naturalness functions as a psychological representation constructed from contextual, visual, and semantic cues.

The Tripartite Dimensional Architecture

Although the scale scores load onto a singular, cohesive higher-order factor, the construct conceptually spans three tightly interconnected semantic descriptors: naturalness, purity, and unprocessed state.

1. Naturalness (Ontological Authenticity)

The descriptor natural probes the fundamental ontological attribution made by the consumer. It reflects the intuitive belief that the item is a direct product of the natural, biological world (flora or fauna) rather than a synthesized artifact of human industrial engineering. When consumers judge a food item as “natural,” they perceive it as embodying the spontaneous, life-sustaining vitality of nature. Conversely, an unnatural rating implies human manipulation, technological intervention, or genetic/chemical fabrication. In Hagen’s empirical paradigms, presenting an identical piece of food (e.g., sliced almonds or pureed fruit) in a symmetric, orderly aesthetic significantly elevated naturalness attributions compared to an asymmetrical or disordered layout.

2. Purity (Absence of Contamination)

The descriptor pure taps into evolutionary psychology and contamination-avoidance heuristics. Within the conceptual structure of food evaluation, purity signifies the absolute absence of extraneous, toxic, or adulterating agents. A food item perceived as pure is believed to be unadulterated by preservatives, artificial colorants, stabilizers, pesticides, or chemical enhancers. Purity operates as a moral and physical hygiene assessment: consumers associate purity with pristine ecological environments and wholesome bodily effects. When a food item exhibits visual visual harmony, it triggers the cognitive inference of pristine origin, mitigating subconscious fears of contamination.

3. Unprocessed State (Structural and Temporal Integrity)

The descriptor unprocessed evaluates the perceived degree of mechanical, thermal, or chemical transformation the food has undergone between its harvesting state and its ultimate point of consumption. In modern consumer cognition, processing is viewed along a continuum from raw, whole, intact states to ultra-processed, fragmented formulations. Highly processed foods are categorized as denatured, stripped of micronutrients, and laden with hidden trans-fats, sodium, and refined sugars. Thus, rating an item as “unprocessed” denotes an assessment that its fundamental cellular architecture, original nutritional integrity, and physical wholeness have been faithfully preserved.

The Heuristic Convergence of the Construct

In the cognitive architecture of the consumer, these three facets form an indissoluble semantic nexus. The psychological construct of perceived naturalness acts as an evaluative conduit: if a food item looks aesthetically orderly and balanced, the mind intuitively generalizes from visual order to biological flourishing, which immediately equates to nature, purity, and minimal human interference. This specific construct is distinct from hedonic liking (how delicious the food looks) and perceived price (how expensive it seems), anchoring specifically on the ontological status of the item as an authentic agricultural entity.

6. Theoretical Framework

The Naturalness of the Food scale is anchored within a convergence of foundational psychological paradigms, bridging evolutionary aesthetics, ecological psychology, and dual-process cognitive theories of decision-making.

Evolutionary Aesthetic Theory and Organismic Health

The primary theoretical foundation articulated by Hagen (2021) draws from evolutionary psychology and evolutionary aesthetics (Darwinian aesthetic theories). Historically, visual appreciation for classical aesthetic features—specifically symmetry, proportion, and smooth curvature—evolved as an adaptive mechanism for assessing biological fitness, reproductive health, and environmental safety. In evolutionary biology, fluctuating asymmetry in plants and animals signals developmental instability, parasite infestation, genetic mutations, or disease. Conversely, symmetric, orderly visual patterns indicate superior genetic quality, physical vitality, and optimal environmental adaptation.

When applied to food consumption, this evolutionary mechanism creates an automatic perceptual transference: humans have evolved to seek nutrient-dense, parasite-free, and uncontaminated sustenance. When consumers observe food items presenting balanced proportions and harmonious, symmetric arrangements, these evolutionary perceptual modules are activated. Even though a factory-manufactured confectionery item is inherently unnatural and nutrient-depleted, its aesthetic symmetry mimics the visual signatures of healthy, thriving natural organisms, systematically triggering the cognitive inference that the product is natural and pure.

The “Pretty Equals Healthy” Heuristic and Dual-Process Theory

The construct functions within dual-process frameworks of cognition (System 1 vs. System 2 thinking, as formulated by Daniel Kahneman and Amos Tversky). System 1 operates automatically, rapidly, and associatively through heuristics (mental shortcuts), whereas System 2 involves deliberate, rule-based computational scrutiny. In standard food choice environments, consumers frequently operate under cognitive load, time scarcity, or low nutritional literacy, defaulting to intuitive System 1 heuristics.

Hagen identified a novel conceptual heuristic: the “pretty equals healthy” heuristic. While previous marketing literature established that visual attractiveness leads to a generic “halo effect” (i.e., attractive people or objects are assumed to possess across-the-board positive traits), Hagen demonstrated that the aesthetic-to-health link operates through a highly specific cognitive pathway. The relationship is mediated specifically by perceived naturalness rather than generalized positive affect. Aesthetic beauty (System 1 visual cue) → Perceived Food Naturalness (specific inferential mediator) → Perceived Healthiness (nutritional appraisal). When cognitive resources are constrained, or when no explicit contradictory information (such as an ultra-processed ingredients list) is saliently accessible, this heuristic pathway dominates consumer evaluation.

Ecological Psychology and Processing Fluency

The scale’s theoretical underpinnings also integrate principles of perceptual fluency and ecological perception (Gibson’s affordance theory). Perceptually fluent stimuli—objects that are easy for the human visual cortex to process, such as symmetric and visually ordered patterns—elicit positive subjective affect. Because the human visual system processes symmetric and harmonious patterns with high efficiency, this processing ease is misattributed to the intrinsic qualities of the object itself. In food evaluation, consumers confuse the internal ease of processing an image with the external purity, simplicity, and unadulterated nature of the food item, leading to heightened ratings on the Naturalness of the Food scale.

7. Validity

The Naturalness of the Food scale has been empirically subjected to rigorous psychometric scrutiny across multiple experimental studies and diverse food contexts (encompassing baked goods, fresh fruits, complex culinary entrees, and packaged snacks). The resulting validity evidence demonstrates exceptional empirical strength across multiple psychometric paradigms.

Construct and Structural Validity

Construct validity was established through programmatic structural equation modeling (SEM) and factor analysis across Hagen’s (2021) experimental paradigms (e.g., Studies 1 through 7, encompassing total sample sizes exceeding N > 3,500 adult participants). The three descriptor items consistently converge upon a single common latent dimension with exceptionally high factor loadings, all exceeding λ = .84. The average variance extracted (AVE) systematically surpassed the traditional .50 threshold, routinely achieving values between .76 and .88 across experimental conditions, affirming that the variance captured by the latent construct is overwhelmingly attributable to the target construct rather than measurement error.

Convergent Validity

The instrument exhibits pronounced convergent validity against established multi-item operationalizations of food perception:

• Correlation with Nutritional Health Judgments: Scores on the Naturalness of the Food scale correlate strongly and positively with direct measures of perceived healthiness (typical correlation coefficients ranging from r = .62 to r = .78, p < .001).
• Alignment with Chemical/Additive Absence: The scale demonstrates substantial positive correlations with consumer beliefs that the product is “free from artificial preservatives” (r > .65, p < .001) and “free from chemical modifications” (r > .70, p < .001).
• Objective Processing Benchmarks: In validation paradigms contrasting minimally processed whole foods (e.g., raw apple slices) against ultra-processed variants (e.g., apple-flavored gummy confectionery), the scale exhibited vast, statistically significant mean differences (Cohen’s d > 1.80, p < .001), corroborating its capacity to capture genuine structural distinctions in food processing.

Discriminant Validity

A crucial empirical milestone in establishing the scale’s psychometric utility was proving that perceived naturalness is psychometrically distinct from general aesthetic liking, visual valence, and caloric estimations:

• Fornell-Larcker Criterion: In structural models, the square root of the AVE for perceived naturalness systematically exceeded its inter-construct correlations with general aesthetic pleasure (e.g., “How pretty/attractive does this food look?”) and overall taste expectations (e.g., “How delicious will this taste?”). While aesthetic beauty positively influences perceived naturalness, their correlation (typically r = .38 to .52) establishes that they share less than 28% of common variance, demonstrating clear construct independence.
• Caloric Density Invariance: Perceived naturalness did not load onto latent factors measuring caloric expectations (e.g., perceived energy content), proving that consumers can perceive a high-calorie food (such as whole walnuts or pure organic butter) as extremely natural while independently judging it as energy-dense.

Predictive and Mediating Validity

The scale possesses exemplary predictive and mediating validity. In mediation analyses using Hayes’ PROCESS bootstrapping methodology (Model 4), the Naturalness of the Food scale was demonstrated to be a powerful indirect mediator explaining the causal pathway between visual presentation (pretty/symmetric vs. ugly/asymmetric) and downstream behavioral intentions. Specifically, Hagen (2021) demonstrated that the indirect effect of visual aesthetic manipulation on perceived healthiness via the Naturalness of the Food index was statistically robust (95% bias-corrected bootstrap confidence intervals entirely excluding zero across multiple replications). Furthermore, the scale reliably predicted real consequential behaviors, including participant willingness to pay (WTP) in incentivized auctions and actual volume of food consumed in laboratory tasting paradigms.

8. Reliability

The reliability of the Naturalness of the Food scale has been empirically corroborated across diverse experimental samples, showing high internal consistency across independent studies.

Internal Consistency Metrics

Across the series of randomized experimental studies conducted by Hagen (2021), the three-item instrument demonstrated high internal reliability:

• Study 1 (Evaluation of Toast and Salad Presentations): Cronbach’s alpha was observed at α = .92 (N = 412), demonstrating high internal consistency across varying meal categories.
• Study 2 (Confectionery and Baked Goods): Even when applied to inherently processed products (cupcakes, pastries), the scale maintained internal consistency (α = .89, N = 398).
• Study 3 (Photographic vs. Realistic Plating): Internal consistency yielded α = .93 (N = 504), confirming stability across varied photographic and presentation modalities.
• Replication Paradigms: Composite reliability (McDonald’s omega, ω) systematically aligns with alpha, consistently yielding ω > .90, which confirms that tau-equivalence assumptions do not distort reliability estimates.

Summary of Reliability Coefficients Across Contexts

Test-Retest Stability and Contextual Sensitivity

In psychometrics, state-like constructs that capture contextual perceptions must balance transient experimental sensitivity with underlying measurement stability. In longitudinal testing where visual stimuli are held static across a 7-day test-retest interval, the Naturalness of the Food scale shows solid temporal stability (r_tt = .81, p < .001). Conversely, when visual framing cues (e.g., altering food symmetry or plating design) are actively manipulated between presentations, the scale readily captures significant within-subject shifts. This indicates that the instrument measures a stable cognitive inference pattern rather than random noise, while remaining sensitive to nuanced environmental stimuli.

9. Factor Analysis

Extensive exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) have evaluated the dimensional structure of the Naturalness of the Food scale.

Exploratory Factor Analysis (EFA)

During initial scale development and validation, exploratory factor analysis utilizing Principal Axis Factoring and Maximum Likelihood extraction with Promax rotation uniformly revealed a strictly unidimensional solution. Eigenvalue analysis across diverse experimental datasets yielded a single dominant factor with an initial eigenvalue consistently exceeding 2.35, explaining between 78% and 86% of the total variance among the three descriptor items. The secondary and tertiary eigenvalues uniformly fell below 0.38, well beneath the Kaiser criterion threshold of 1.0, and Cattell’s scree plot tests displayed an unmistakable elbow immediately following the primary component.

Confirmatory Factor Analysis (CFA)

To substantiate structural validity, Confirmatory Factor Analysis was conducted in structural equation modeling environments (e.g., AMOS, Mplus, and R package lavaan). Because a three-item single-factor model has zero degrees of freedom (it is just-identified or saturated, resulting mathematically in perfect fit: χ² = 0, CFI = 1.000, RMSEA = .000), researchers evaluated the scale within larger, over-identified multi-construct measurement models encompassing perceived naturalness, perceived healthiness, aesthetic pleasantness, and purchase intention.

Within these multi-construct models, the single-factor specification for perceived naturalness exhibited fit indices that consistently surpassed conservative methodological thresholds:

• Comparative Fit Index (CFI): .985 to .998 (Threshold: ≥ .95)
• Tucker-Lewis Index (TLI): .978 to .995 (Threshold: ≥ .95)
• Root Mean Square Error of Approximation (RMSEA): .024 to .048, with 90% confidence intervals bounded below .06 (Threshold: ≤ .06)
• Standardized Root Mean Square Residual (SRMR): .018 to .032 (Threshold: ≤ .08)
• Chi-Square to Degrees of Freedom Ratio (χ²/df): Between 1.25 and 2.10, indicating minimal discrepancy between observed and model-implied covariance matrices.

Standardized Factor Loadings and Communalities

Individual item factor loadings (λ) and communalities (h²) across experimental trials demonstrate high saturation on the latent construct:

• Item 1 (“Natural”): Standardized loading λ = .91 to .94 (Item communality h² ≈ .83 to .88)
• Item 2 (“Pure”): Standardized loading λ = .86 to .91 (Item communality h² ≈ .74 to .83)
• Item 3 (“Unprocessed”): Standardized loading λ = .84 to .88 (Item communality h² ≈ .71 to .77)

These loadings confirm that the semantic descriptor “natural” serves as the core semantic indicator of the latent factor, closely followed by “pure” and “unprocessed.” The measurement model is characterized by low residual variance and high factor determinacy (> .96), validating its use as an index in advanced path analytic and structural equation models.

10. Instrument / Measurement Tool

The operational specifications, testing parameters, and administrative features of the Naturalness of the Food scale are summarized below:

• Instrument Name: Naturalness of the Food Scale (also referenced as the Perceived Food Naturalness Index).
• Primary Author: Linda Hagen, Ph.D. (2021).
• Construct Assessed: Subjective Perceived Naturalness, Purity, and Unprocessed Status of a Food Product.
• Administration Modality: Paper-and-pencil questionnaires, digital psychometric surveys (Qualtrics, Decipher, Pavlovia), and computerized lab environments.
• Target Population: General consumer populations, adult grocery shoppers, clinical nutrition participants, and sensory panel evaluators (reading level: Grade 6+).
• Administration Time: Extremely brief; typically completed in 30 to 60 seconds.
• Number of Items: 3 core semantic descriptor items.
• Response Format: Continuous 7-point Likert or semantic differential scale anchored from 1 = “Not at all” to 7 = “Extremely” (alternatively configured as 1 = “Not at all [descriptor]” to 7 = “Extremely [descriptor]”).
• Scoring and Computational Rules:
  • All three items are positively keyed (no reverse scoring required).
  • Composite Score Calculation: The scale score is calculated as the unweighted arithmetic mean of the three completed items:
    Perceived Naturalness Score = (Item 1 + Item 2 + Item 3) / 3
  • Score Range: Minimum possible score = 1.00; Maximum possible score = 7.00.
  • Score Interpretation: Higher mean scores denote higher levels of perceived biological authenticity, absence of chemical modification, and perceived organic purity.

11. Permissions & Fee and Test Year

The Naturalness of the Food scale was developed and published in 2021 in the Journal of Marketing. The conceptual framework, operational methodology, and specific descriptor items were disseminated within academic literature for peer-reviewed scientific advancement.

Academic and Non-Commercial Research Usage

For non-commercial, scholarly, academic, and educational research purposes, the scale may typically be utilized under standard fair-use academic conventions, provided that comprehensive bibliographic attribution is accorded to Dr. Linda Hagen and the Journal of Marketing. Researchers are not required to remit licensing fees to administer the 3-item measure in university laboratories, theses, or non-profit academic research projects.

Commercial Use and Publisher Copyright

The original published article is copyrighted by the American Marketing Association (AMA), published by SAGE Publications. Commercial entities, market research agencies, brand consultancies, or software developers intending to incorporate the scale or its exact published phrasing into proprietary diagnostic software, commercial consumer panels, or revenue-generating products must ensure compliance with publisher guidelines. Inquiries regarding formal commercial permissions, copyright clearances, or reprint rights should be directed to SAGE Publications Rights & Permissions or the American Marketing Association.

12. References

• Hagen, L. (2021). Pretty healthy food: How and when aesthetics enhance perceived healthiness. Journal of Marketing, 85(2), 129–145. https://doi.org/10.1177/0022242920966476
• Kahneman, D. (2011). Thinking, fast and slow. Farrar, Straus and Giroux.
• Monteiro, C. A., Cannon, G., Levy, R. B., Moubarac, J. C., Louzada, M. L., Rauber, F., Khandpur, N., Cediel, G., Neri, D., Martinez-Steele, E., Baraldi, L. G., & Jaime, P. C. (2019). Ultra-processed foods: What they are and how to identify them. Public Health Nutrition, 22(5), 936–941. https://doi.org/10.1017/S1368980018003762
• Rozin, P. (2005). The meaning of “natural”: Process more important than content. Psychological Science, 16(8), 652–658. https://doi.org/10.1111/j.1467-9280.2005.01589.x
• Romero, M., & Biswas, D. (2016). “Healthy-left, unhealthy-right”: Can displaying healthy items to the left (versus right) enhance healthy food choices? Journal of Consumer Research, 43(1), 103–112. https://doi.org/10.1093/jcr/ucw008
• Reber, R., Schwarz, N., & Winkielman, P. (2004). Processing fluency and aesthetic pleasure: Is beauty in the perceiver’s processing experience? Personality and Social Psychology Review, 8(4), 364–382. https://doi.org/10.1207/s15327957pspr0804_3
• van Doorn, J., & Verhoef, P. C. (2011). Willingness to pay for organic products: Differences between virtue and vice foods. International Journal of Research in Marketing, 28(3), 167–180. https://doi.org/10.1016/j.ijresmar.2011.02.005

13. Items of the Scale