{n “title”: “Curiosity and Exploration Inventory-II (CEI‐II)”,n “excerpt”: “The Curiosity and Exploration Inventory-II (CEI-II) is a validated 10-item self-report psychometric instrument designed by Kashdan and colleagues to evaluate trait curiosity across two distinct dimensions: stretching and embracing.”,n “slug”: “curiosity-and-exploration-inventory-ii-cei-ii”,n “categories”: [n “Psychological Assessment”,n “Positive Psychology”,n “Personality Measurement”n ],n “tags”: [n “Curiosity”,n “CEI-II”,n “Exploration”,n “Personality Assessment”,n “Stretching”,n “Embracing”,n “Todd Kashdan”,n “Positive Psychology”,n “Psychometrics”n ],n “seo_title”: “Curiosity and Exploration Inventory-II (CEI-II): Psychometric Review”,n “seo_description”: “An exhaustive psychometric review of the Curiosity and Exploration Inventory-II (CEI-II), including theoretical framework, factor structure, scoring, and scale items.”,n “focus_keyword”: “Curiosity and Exploration Inventory-II”,n “content”: “
Abstract
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The Curiosity and Exploration Inventory-II (CEI-II) is a psychometrically validated self-report assessment developed to operationalize and measure individual differences in trait curiosity and exploratory behavior. Designed by Todd B. Kashdan and colleagues in 2009 as a substantive refinement of the original Curiosity and Exploration Inventory (CEI; Kashdan et al., 2004), the CEI-II rectifies psychometric limitations identified in the original scale, including restricted content coverage and subscale instability. The instrument comprises 10 items rated on a 5-point Likert-type scale spanning from 1 (\”Very Slightly or Not At All\”) to 5 (\”Extremely\”).
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The instrument captures curiosity as an appetitive motivational state that drives purposeful engagement with novel, complex, and unpredictable stimuli. Structurally, the scale is bifurcated into two correlated, psychometrically robust dimensions: Stretching (5 items), which indexes the active motivation to seek out novel knowledge, information, and challenging experiences to broaden personal boundaries; and Embracing (5 items), which indexes the dispositional willingness to engage with, adapt to, and tolerate the uncertainty, unpredictability, and tension inherent in everyday lived experience.
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Across validation studies spanning independent collegiate and adult community samples, the CEI-II demonstrates exceptional psychometric properties. Confirmatory factor analyses consistently substantiate a two-factor correlated model or a hierarchical bifactor structure yielding superior fit indices compared to unidimensional alternatives (e.g., Comparative Fit Index [CFI] > .95, Root Mean Square Error of Approximation [RMSEA] < .06). Internal consistency coefficients are consistently robust across both subscales ($\\alpha \\approx .75-.86$) and the total score ($\\alpha > .85$), paired with solid test-retest reliability across multiple assessment intervals. The CEI-II displays strong convergent validity with openness to experience, positive affectivity, intrinsic motivation, and generalized self-efficacy, alongside sharp discriminant validity against social desirability, sensation seeking, and psychological distress.
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Keywords
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Curiosity and Exploration Inventory-II, CEI-II, trait curiosity, exploratory behavior, stretching, embracing, positive psychology, psychometrics, epistemic curiosity, personality measurement
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Authors
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The Curiosity and Exploration Inventory-II was conceptualized, validated, and published by a collaborative team of quantitative and personality psychologists led by Todd B. Kashdan:
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- Todd B. Kashdan, Ph.D.: Professor of Psychology and Senior Scholar at the Center for the Advancement of Well-Being, George Mason University, Fairfax, VA, USA. Dr. Kashdan’s research focuses on curiosity, psychological flexibility, well-being, and social relationships.
- Matthew W. Gallagher, Ph.D.: Associate Professor of Clinical Psychology and Research Director at the Texas Center for Brain Injury and Repair, University of Houston, Houston, TX, USA. His scholarship specializes in quantitative methodologies, anxiety disorders, and resilience.
- Paul J. Silvia, Ph.D.: Lucy Spinks Keker Excellence Professor of Psychology, University of North Carolina at Greensboro, Greensboro, NC, USA. A leading theorist on interest, aesthetics, and curiosity-driven cognition.
- William E. Breen, Ph.D.: Clinical Psychologist affiliated with George Mason University during scale inception, specializing in anxiety, emotion regulation, and experiential avoidance.
- Danielle Terhar, B.A.: Research Associate in the Laboratory for the Study of Social Anxiety, Character Strengths, and Well-Being, George Mason University.
- Michael F. Steger, Ph.D.: Professor of Psychology and Director of the Center for Meaning and Purpose, Colorado State University, Fort Collins, CO, USA. Renowned for structural modeling of meaning in life, well-being, and human flourishing.
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Purpose
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The primary purpose of the Curiosity and Exploration Inventory-II (CEI-II) is to provide an empirically grounded, psychometrically sound, and theoretically coherent metric for assessing curiosity as an enduring individual difference. Historically, psychological research struggled to isolate curiosity from related affective and cognitive constructs, often conflating curiosity with general sensation seeking, reward dependence, or intellectual aptitude. The CEI-II was developed specifically to address the structural and theoretical gaps present in earlier instruments, including the original CEI (Kashdan et al., 2004), which had conflated the motivational orientation of curiosity with flow-like experiential absorption.
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In clinical, counseling, and organizational settings, measuring curiosity provides indispensable insights into how individuals respond to environmental distress, ambiguity, and transition. In clinical psychology, low trait curiosity functions as a vulnerability marker for major depressive disorder and experiential avoidance syndromes. Individuals characterized by diminished curiosity often perceive ambiguous stimuli through a threat-based lens, retreating into avoidance behaviors that reinforce pathology. Conversely, individuals scoring high on the CEI-II demonstrate resilience against interpersonal aggression and social anxiety, utilizing proactive cognitive reappraisal and exploratory coping when confronted with threatening or destabilizing events.
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In educational and workplace contexts, the CEI-II serves as an index of intrinsic academic motivation, creative problem-solving capacity, and adaptive performance. Rather than viewing ambiguity as an impediment, individuals high in stretching actively pursue complex information architectures, while those high in embracing thrive under conditions of rapid workplace transformation and organizational volatility. Consequently, researchers utilize the CEI-II to predict creative output, self-regulated learning, interpersonal intimacy, and long-term psychological flourishing.
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Psychological Construct
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Curiosity is defined within contemporary personality science as the recognition, pursuit, and intense desire to explore novel, challenging, and uncertain events. Far from being a passive cognitive reaction, curiosity represents an approach-oriented motivational engine that energizes human development and behavioral adaptation. The CEI-II models curiosity across two distinct yet inter-correlated behavioral dimensions: Stretching and Embracing.
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The Dimension of Stretching
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The Stretching dimension captures an individual’s active, intentional drive to expand their intellectual, physical, and experiential horizon. Individuals who demonstrate high stretching scores actively seek out situations characterized by complexity, novelty, and conceptual depth. Stretching encompasses the proactive, self-directed search for stimuli that exceed current knowledge structures, compelling the cognitive architecture to assimilate new information or accommodate existing mental schema. Exemplified by items such as \”I actively seek as much information as I can in new situations\” and \”I am at my best when doing something that is complex or challenging,\” this dimension aligns with the epistemic search for mastery, knowledge construction, and intellectual expansion.
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The Dimension of Embracing
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In contrast, the Embracing dimension assesses an individual’s affective and behavioral posture toward the emergent, unpredictable, and ambiguous aspects of life. While stretching concerns active seeking, embracing focuses on experiential openness to ambiguity and the willingness to welcome situational instability without feeling distressed. In natural environments, the search for novelty is inherently accompanied by uncertainty, vulnerability, and unpredictable outcomes. Embracing represents the capacity to lean into this experiential tension rather than retreating to familiar, safe, or ritualized behavioral repertoires. Exemplified by items such as \”I am the type of person who really enjoys the uncertainty of everyday life\” and \”I like to do things that are a little frightening,\” embracing reflects low experiential avoidance, tolerance for psychological tension, and appetitive engagement with risk.
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Theoretical Framework
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The theoretical framework underlying the CEI-II synthesizes decades of foundational research across cognitive, motivational, and evolutionary psychology. The scale integrates Daniel Berlyne’s pioneer arousal-potential model, Self-Determination Theory, and Barbara Fredrickson’s Broaden-and-Build Theory of positive emotions.
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Berlyne’s Collative Variables and Curiosity Drive
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Daniel Berlyne (1960) established that exploratory behavior is elicited by \”collative variables\”—stimulus characteristics including novelty, complexity, uncertainty, and ambiguity. Berlyne posited that these properties introduce cognitive conflict, driving individuals to explore their surroundings to reconcile information discrepancies. The CEI-II adapts Berlyne’s framework by shifting from a purely tension-reduction view (curiosity as an unpleasant deficit state) toward an appetitive view, wherein individuals actively cultivate and enjoy moderate levels of cognitive tension, novelty, and complexity as intrinsically rewarding experiences.
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Self-Determination Theory (SDT)
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Within Self-Determination Theory formulated by Edward Deci and Richard Ryan, curiosity operates as the quintessential prototype of intrinsic motivation. Humans possess an innate, organismic inclination toward growth, integration, and environmental mastery. The CEI-II dimensions directly map onto the psychological needs for competence and autonomy. Stretching serves the need for competence by expanding cognitive structures through deliberate challenge; embracing serves autonomy and environmental interaction by freeing the individual from rigid, defensive scripts, permitting spontaneous exploration of diverse contexts.
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The Broaden-and-Build Model
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Barbara Fredrickson’s (2001) Broaden-and-Build Theory provides a compelling evolutionary explanation for trait curiosity. Unlike negative emotions that narrow cognitive and behavioral repertoires to immediate survival mechanisms (e.g., flight or fight), curiosity broadens momentary thought-action repertoires. When individuals experience interest and exploratory impulses, their behavioral field expands to include learning, play, and observation. Over time, these transient states build enduring personal resources, including intellectual mastery, creative problem-solving skills, and social networks.
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Validity
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The psychometric integrity of the CEI-II has been confirmed through comprehensive construct, convergent, discriminant, and incremental validity evaluations.
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Construct and Structural Validity
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During the initial development across large university samples (Sample 1: $N = 311$; Sample 2: $N = 334$), Kashdan et al. (2009) employed both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). A two-factor correlated model outperformed single-factor formulations across all samples. Standardized factor loadings across items ranged robustly from .60 to .85, confirming that the ten items adequately reflect the two hypothesized latent dimensions without problematic cross-loadings.
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Convergent Validity
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The CEI-II exhibits moderate-to-strong positive correlations with closely related psychological constructs:
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- Openness to Experience: High correlations with the Big Five Openness domain ($r = .45$ to $.58$), particularly with the subfacets of Ideas and Actions.
- Positive Affectivity: Robust associations with trait positive affect ($r = .40$ to $.55$) on the Positive and Negative Affect Schedule (PANAS).
- Psychological Well-Being: Strong associations with subjective vitality ($r = .48$), autonomous self-regulation ($r = .42$), and presence of meaning in life ($r = .38$).
- Mindfulness and Flow: Positive associations with self-reported mindfulness ($r = .35$) and dispositional flow ($r = .44$).
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Discriminant Validity
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Crucially, the CEI-II demonstrates clear separation from overlapping constructs:
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- Sensation Seeking: Although both involve novel experiences, the CEI-II correlates only moderately with sensation seeking ($r = .32$ to $.40$). Unlike Zuckerman’s sensation seeking scale—which reflects impulsivity, thrill-seeking, and behavioral disinhibition—the CEI-II specifically taps epistemic motivation, personal growth, and intellectual development.
- Social Desirability: Correlations with the Marlowe-Crowne Social Desirability Scale are non-significant ($r = .04$ to $.09$), indicating that scores are not contaminated by impression management or self-deceptive enhancement.
- Negative Affect and Neuroticism: The CEI-II exhibits small-to-moderate inverse correlations with neuroticism ($r = -.20$ to $-.31$) and depressive symptom severity ($r = -.24$).
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Reliability
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The CEI-II demonstrates strong internal consistency and temporal stability across diverse participant populations, ranging from undergraduate cohorts to representative adult demographic samples.
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Internal Consistency
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Across validation studies reported by Kashdan et al. (2009), Cronbach’s coefficient alpha ($\\alpha$) for the overall 10-item CEI-II composite demonstrated excellent internal consistency, regularly falling between $.83$ and $.86$. Reliability estimates for the individual 5-item subscales showed similar psychometric adequacy:
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- Stretching Subscale: Cronbach’s $\\alpha$ coefficients consistently range from $.75$ to $.82$. Corrected item-total correlations range from $.48$ to $.68$.
- Embracing Subscale: Cronbach’s $\\alpha$ coefficients consistently range from $.74$ to $.80$. Corrected item-total correlations range from $.45$ to $.66$.
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Temporal Stability (Test-Retest Reliability)
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Test-retest evaluations over multi-week intervals demonstrate that the CEI-II reliably captures curiosity as a stable personality trait rather than an ephemeral psychological state. Over a two-week interval, test-retest reliability was $r = .80$ for the overall scale, $r = .79$ for Stretching, and $r = .78$ for Embracing. Over an extended eight-week retest window, temporal stability remained substantial ($r = .71$ for the composite score), affirming that while curious behavior can fluctuate dynamically in response to situational stimuli, dispositional curiosity constitutes an enduring baseline orientation.
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Factor Analysis
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The structural configuration of the CEI-II was rigorously examined through both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) during scale construction.
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Exploratory Factor Analysis (EFA)
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Initial item extraction conducted via maximum likelihood EFA with oblimin rotation on an item pool demonstrated a distinct two-factor solution based on scree plot examination, parallel analysis, and Kaiser’s criterion (eigenvalues > 1.0). The two emergent factors accounted for over 52% of the total variance. Crucially, the items loaded cleanly onto their respective target factors without substantial cross-loadings (all primary loadings > .55; secondary loadings < .22).
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Confirmatory Factor Analysis (CFA)
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Subsequent testing across independent validation samples employed CFA to contrast three competing theoretical structural models:
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- Unidimensional Model: All 10 items loading onto a single general curiosity latent factor.
- Two-Factor Orthogonal Model: Stretching and Embracing specified as completely independent, uncorrelated factors.
- Two-Factor Correlated Model: Stretching and Embracing specified as distinct yet correlated latent dimensions.
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The two-factor correlated model demonstrated superior fit across all fit indices: $\\chi^2(34) = 64.21, p < .001$; $\\text{CFI} = .97$; $\\text{TLI} = .96$; $\\text{RMSEA} = .052$ ($90\\% \\text{ CI } [.033, .070]$); $\\text{SRMR} = .038$. In contrast, the unidimensional model exhibited poor fit ($\\text{CFI} = .83$; $\\text{RMSEA} = .114$). The correlation between the Stretching and Embracing latent factors is typically around $\\phi = .63$, indicating that although they share substantial common variance as elements of a broader curiosity orientation, they retain sufficient independent variance to justify distinct subscales.
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Instrument / Measurement Tool
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- Tool Name: Curiosity and Exploration Inventory-II (CEI-II)
- Target Population: Adults and adolescents aged 16 and older; adapted for research, organizational, and clinical assessments.
- Administration Format: Self-report questionnaire; available in paper-and-pencil or digital/computerized survey formats.
- Estimated Completion Time: Approximately 2 to 3 minutes.
- Total Number of Items: 10 items.
- Response Scale: 5-point Likert-type scale: 1 = Very Slightly or Not At All, 2 = A Little, 3 = Moderately, 4 = Quite a Bit, 5 = Extremely.
- Subscale Breakdown:\n
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- Stretching: Items 1, 3, 5, 7, and 9 (assesses information seeking, growth, and challenge pursuit).
- Embracing: Items 2, 4, 6, 8, and 10 (assesses willingness to embrace everyday unpredictability, ambiguity, and unfamiliarity).
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- Scoring Protocol:\n
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- All items are positively scored; there are no reverse-coded items.
- Stretching Score: Sum or mean of items 1, 3, 5, 7, and 9 (Sum range: 5 to 25).
- Embracing Score: Sum or mean of items 2, 4, 6, 8, and 10 (Sum range: 5 to 25).
- Total Curiosity Score: Sum or mean of all 10 items (Sum range: 10 to 50).
- Higher scores represent greater levels of trait curiosity and exploratory tendencies.
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Permissions & Fee and Test Year
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The Curiosity and Exploration Inventory-II was officially published in 2009 by Todd B. Kashdan, Matthew W. Gallagher, Paul J. Silvia, William E. Breen, Danielle Terhar, and Michael F. Steger in the Journal of Research in Personality.
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The CEI-II is an open-access psychometric instrument made freely available by the developers for non-commercial educational, scientific, and academic research purposes. No licensing fees or royalty payments are required for standard scholarly administration. Researchers and practitioners using the instrument must provide proper academic attribution by citing the primary validation publication (Kashdan et al., 2009). Direct inquiries regarding commercial licensing or organizational distribution should be directed to the primary author, Dr. Todd B. Kashdan.
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References
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Berlyne, D. E. (1960). Conflict, arousal, and curiosity. McGraw-Hill. https://doi.org/10.1037/11164-000
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Fredrickson, B. L. (2001). The role of positive emotions in positive psychology: The broaden-and-build theory of positive emotions. American Psychologist, 56(3), 218–226. https://doi.org/10.1037/0003-066X.56.3.218
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Kashdan, T. B., DeWall, C. N., Pond, R. S., Silvia, P. J., Lambert, N. M., Fincham, F. D., Savostyanova, A. A., & Keller, P. S. (2013). Curiosity protects against interpersonal aggression: Cross-sectional, daily process, and behavioral evidence. Journal of Personality, 81(1), 87–102. https://doi.org/10.1111/j.1467-6494.2012.00783.x
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Kashdan, T. B., Gallagher, M. W., Silvia, P. J., Breen, W. E., Terhar, D., & Steger, M. F. (2009). The Curiosity and Exploration Inventory-II: Development, factor structure, and initial psychometrics. Journal of Research in Personality, 43(6), 987–998. https://doi.org/10.1016/j.jrp.2009.04.011
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Kashdan, T. B., McKnight, P. E., Fincham, F. D., & Rose, P. (2011). When curiosity breeds intimacy: Taking advantage of intimacy opportunities and transforming boring conversations. Journal of Personality, 79(6), 1369–1401. https://doi.org/10.1111/j.1467-6494.2010.00697.x
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Kashdan, T. B., Rose, P., & Fincham, F. D. (2004). Curiosity and exploration: Facilitating positive subjective experiences and personal growth opportunities. Journal of Personality Assessment, 82(3), 291–305. https://doi.org/10.1207/s15327752jpa8203_05
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Ryan, R. M., & Deci, E. L. (2000). Self-determination theory and the facilitation of intrinsic motivation, social development, and well-being. American Psychologist, 55(1), 68–78. https://doi.org/10.1037/0003-066X.55.1.68
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