Inventory of Callous Unemotional Traits (ICU)

1. Abstract

The Inventory of Callous-Unemotional Traits (ICU) is a standardized psychometric assessment designed to evaluate callous and unemotional (CU) traits in children, adolescents, and emerging adults. Conceptualized as the affective core of psychopathy, CU traits are characterized by profound deficits in affective empathy, an absence of guilt or remorse, indifference to the feelings and well-being of others, and diminished emotional expression. Developed by Paul J. Frick in 2004 to overcome the psychometric and conceptual limitations of earlier omnibus rating scales (such as the Antisocial Process Screening Device), the ICU comprises 24 items scored on a 4-point Likert scale ranging from 0 (“Not at all true”) to 3 (“Definitely true”). The instrument yields a total composite score and three distinct subscale dimensions: Callousness, Uncaring, and Unemotional. The instrument is operationalized across multiple informant modalities (self-report, parent-report, and teacher-report) and age-adapted versions spanning early childhood through late adolescence. Extensively validated internationally across community, clinic-referred, and juvenile justice populations, structural research consistently supports a bifactor or hierarchical three-factor configuration, demonstrating robust internal consistency (total scale Cronbach’s α typically .77 to .89), solid cross-informant convergence, and high predictive validity for persistent conduct problems, violent recidivism, instrumental aggression, and blunted physiological reactivity to distress cues. The ICU plays a pivotal role in operationalizing the “with Limited Prosocial Emotions” (LPE) specifier for Conduct Disorder introduced in the DSM-5 and ICD-11, making it an indispensable tool within clinical diagnostics, juvenile forensic evaluations, and developmental psychopathology research.

2. Keywords

Inventory of Callous-Unemotional Traits, ICU, callous-unemotional traits, psychopathy, conduct disorder, limited prosocial emotions, affective empathy, adolescent aggression, juvenile delinquency, psychometrics, factor analysis, Paul J Frick

3. Authors

The Inventory of Callous-Unemotional Traits was developed by Paul J. Frick, Ph.D., Roy Crumpler Memorial Chair and Professor in the Department of Psychology at Louisiana State University (Baton Rouge, Louisiana, USA) and Professorial Fellow at the Institute for Learning Sciences and Teacher Education at Australian Catholic University (Brisbane, Australia). Dr. Frick originally drafted the scale while serving on the faculty of the Department of Psychology at the University of New Orleans.

Subsequent psychometric validation, cross-cultural adaptation, and developmental standardization programs have been conducted in close collaboration with prominent developmental and forensic psychopathy scholars, including:

• Eva R. Kimonis, Ph.D. — School of Psychology, University of New South Wales (UNSW Sydney), Australia.
• Cecilia A. Essau, Ph.D. — Department of Psychology, University of Roehampton, London, United Kingdom.
• Kostas A. Fanti, Ph.D. — Department of Psychology, University of Cyprus, Nicosia, Cyprus.
• Annalaura Ciucci, Ph.D. — Department of Education, Languages, Intercultures, Literatures and Psychology, University of Florence, Italy.
• Patricia Bijttebier, Ph.D. — Faculty of Psychology and Educational Sciences, KU Leuven, Belgium.

Contact Information: Inquiries regarding authorized clinical and research administration protocols can be directed to Dr. Paul J. Frick at [email protected] or via the Developmental Psychopathology Laboratory at Louisiana State University.

4. Purpose

The primary purpose of the Inventory of Callous-Unemotional Traits (ICU) is to provide a comprehensive, developmentally calibrated, and psychometrically robust measurement of the affective dimension of psychopathy in children and adolescents. Historically, youth exhibiting severe conduct problems were conceptualized as an etiologically homogeneous cohort characterized by poor impulse control, defiance, and overt aggression. However, longitudinal developmental research led by Dr. Paul J. Frick and colleagues demonstrated that youths with severe conduct problems comprise at least two distinct developmental phenotypes: an emotionally dysregulated, impulsive subgroup showing heightened reactive aggression, and an affective-deficit subgroup marked by low empathy, shallow affect, instrumental (proactive) aggression, and pervasive uncaring attitudes.

Prior to the construction of the ICU, researchers and clinicians assessed callous-unemotional features using brief subscales embedded in broader behavioral rating scales, such as the 6-item CU subscale of the Antisocial Process Screening Device (APSD) or items derived from the Psychopathy Checklist: Youth Version (PCL:YV). These early measures exhibited notable structural constraints: they possessed few items, poor internal reliability (often with Cronbach’s alpha falling below .60), significant ceiling or floor effects, and an over-reliance on negatively worded items that captured severe antisocial pathology without capturing the broader continuum of prosocial emotion and empathic concern.

The ICU was purposefully designed to address these psychometric vulnerabilities by:

• Expanding Construct Coverage: Providing an in-depth, 24-item operationalization that samples multiple facets of the affective dimension, including lack of remorse, deficient empathy, unconcern about performance, and constricted emotional expression.
• Balancing Valence to Minimize Response Bias: Incorporating a balanced distribution of positively worded items (e.g., “I express my feelings openly”, “I feel bad or guilty when I do something wrong”) and negatively worded items (e.g., “The feelings of others are unimportant to me”) to control for acquiescence bias and method artifacts.
• Facilitating Multi-Informant Diagnostic Triangulation: Providing parallel forms across self-report, parent-report, and teacher-report configurations, enabling clinicians to synthesize observations across domestic, academic, and clinical environments.
• Operationalizing Diagnostic Specifiers: Supplying an empirical evidence base for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and the World Health Organization’s ICD-11 “with Limited Prosocial Emotions” (LPE) specifier for Conduct Disorder.

In clinical practice, the ICU serves as a specialized risk-stratification instrument. Youth scoring elevated on the ICU exhibit an elevated trajectory toward persistent, violent offending, institutional infraction, and poor responsiveness to standard anger-management and behavioral modification therapies. Consequently, identifying these traits allows clinicians to tailor evidence-based parent management training and empathy-enhancement interventions specifically targeted to low-affective profiles.

5. Psychological Construct

The Inventory of Callous-Unemotional Traits measures a multidimensional psychological construct that reflects abnormal affective empathy and interpersonal detachment. Within contemporary developmental psychopathology, callous-unemotional traits represent the childhood and adolescent analogue to Factor 1 (interpersonal/affective) of adult psychopathy. Rather than tapping overt behavioral violations, executive dysfunction, or impulse control failures, the ICU isolates the affective-interpersonal core across three interrelated dimensions: Callousness, Uncaring, and Unemotional.

5.1. Callousness Subscale

The Callousness dimension comprises 11 items reflecting a pervasive deficit in affective empathy, indifference to the suffering or distress of others, active cruelty, and exploitative interpersonal behavior. Individuals scoring high on Callousness demonstrate an explicit disregard for relational harm, viewing others instrumentally as tools for personal gain. Items capture statements reflecting cold indifference to inflicting harm (e.g., unconcern over hurting others’ feelings or taking advantage of others). This subscale exhibits the strongest empirical associations with proactive, pre-meditated aggression, delinquent peer affiliations, sadistic or predatory behavior, and a profound lack of remorse following severe social transgressions.

5.2. Uncaring Subscale

The Uncaring dimension consists of 8 items indexing an unconcerned attitude toward one’s own performance, lack of conscientiousness, indifference to expectations, and apathy regarding standard social obligations. Items within this factor predominantly reflect reversed prosocial orientations, tapping a lack of effort in school, disregard for disciplinary consequences (e.g., not caring about being disciplined or receiving poor marks), and indifference to fulfilling personal commitments. High scores on the Uncaring subscale characterize youth who are impervious to normative motivational structures, demonstrating resistance to typical social reinforcers such as praise, parental disappointment, or academic achievement.

5.3. Unemotional Subscale

The Unemotional dimension encompasses 5 items capturing restricted affect, suppression or absence of emotional expression, and masking of emotional vulnerability. Items in this subscale measure how openly or intensely individuals display emotions to peers and caregivers (e.g., hiding feelings, appearing cold, or showing little outward distress or warmth). While the Callousness and Uncaring subscales consistently correlate strongly with severe conduct problems, the Unemotional subscale displays unique psychometric properties. In neurobiological research, it often dissociates from overt behavioral delinquency, instead reflecting an atypical blunting of both positive and negative valence systems, autonomic hypoarousal, and hyporesponsiveness of the amygdala to fearful facial expressions.

5.4. Clinical and Behavioral Manifestations

When these three dimensions converge into an elevated total ICU score, the youth presents a distinct neurocognitive and behavioral phenotype:

• Reward Dominance and Punishment Insensitivity: These youths perseverate on anticipated rewards while displaying blunted behavioral inhibition when faced with punitive sanctions.
• Distorted Moral Reasoning: Moral transgressions are evaluated based on the likelihood of detection and personal utility rather than the perceived emotional pain caused to the victim.
• Deficits in Distress-Cue Recognition: Impaired capacity to process vocal distress, pain, and fearful facial expressions in others, underpinning their profound empathy deficits.

6. Theoretical Framework

The development of the ICU is grounded in developmental psychopathology, affective neuroscience, and evolutionary personality theory. It specifically synthesizes James Blair’s Integrated Emotion System (IES) model and Violence Inhibition Mechanism (VIM) with Paul J. Frick’s dual-pathway developmental model of severe conduct problems.

6.1. The Violence Inhibition Mechanism and Amygdala Dysregulation

Blair’s Violence Inhibition Mechanism posits that normative human socialization relies on an innate neurocognitive mechanism triggered by distress cues (e.g., crying, fearful vocalizations, submissive postures). When a typically developing child observes distress in another, the display functions as an unconditioned aversive stimulus, activating the amygdala, provoking autonomic arousal, and terminating the aggressive behavior. Through classical conditioning, the mental representation of distress cues becomes linked to moral prohibitions.

The theoretical premise underlying the ICU is that youth with elevated CU traits possess an innate structural or functional impairment within the amygdala-ventromedial prefrontal cortex (vmPFC) circuitry. Because distress cues fail to trigger autonomic arousal or neural activation in the amygdala, these individuals do not experience the vicarious aversive state that normally inhibits violent or antisocial actions. Aggression is therefore unconstrained by empathy or remorse.

6.2. Frick’s Dual-Pathway Model

The developmental theoretical framework formulated by Dr. Paul J. Frick posits two divergent developmental pathways toward chronic Conduct Disorder:

1. The Emotionally Dysregulated / Impulsive Pathway: Characterized by high emotional lability, autonomic hyperreactivity, executive functioning deficits, and poor impulse control. Aggression in this pathway is predominantly reactive, representing an explosive, hostile response to perceived threats or interpersonal provocations.
2. The Callous-Unemotional Pathway: Characterized by autonomic hyporeactivity, low resting heart rate, blunted skin conductance responses, reward dominance, and normal or superior executive functioning. Aggression in this pathway is primarily instrumental (proactive)—cold, planned, goal-directed, and utilized to obtain power, money, or social status.

The ICU serves as the dedicated measurement operationalization of this second pathway, isolating the affective substrate that decouples severe behavioral problems from emotional distress or reactive anger.

6.3. Evolutionary and Social Information Processing Perspectives

From an evolutionary framework, callous-unemotional traits have been conceptualized as reflecting a “fast” life-history strategy adapted for low-trust, competitive environments where cooperation is disadvantageous and exploitation maximizes resource acquisition. In terms of Kenneth Dodge’s Social Information Processing (SIP) model, whereas reactive aggressive youths exhibit a hostile attribution bias (interpreting benign actions as hostile), youths with elevated ICU scores display atypical outcome expectancies: they expect aggression to result in tangible rewards and social dominance, and they evaluate aggressive acts as comfortable, appropriate, and effective.

7. Validity

The construct, convergent, discriminant, and predictive validity of the Inventory of Callous-Unemotional Traits has been rigorously documented across diverse international cohorts, spanning community, school-based, psychiatric, and juvenile forensic samples.

7.1. Convergent Validity

The ICU exhibits strong, theoretically coherent correlations with established psychopathy and conduct problem indices:

• Psychopathy Indices: Across clinical and forensic samples of adolescents, ICU total scores correlate robustly with the Psychopathy Checklist: Youth Version (PCL:YV) Factor 1 (affective/interpersonal facet), yielding correlation coefficients ranging between r = .52 and r = .68 (Kimonis et al., 2008, 2014). It correlates significantly with the Antisocial Process Screening Device (APSD) Callous-Unemotional subscale (r = .60 to .74).
• Empathy Deficits: Scores demonstrate strong negative associations with validated empathy inventories, such as the Basic Empathy Scale (BES) and the Interpersonal Reactivity Index (IRI), specifically reflecting deep deficits in affective/emotional empathy (r = -.45 to -.62) alongside preserved or only mildly reduced cognitive perspective-taking (Jones et al., 2010).

7.2. Discriminant Validity

A critical psychometric strength of the ICU is its ability to dissociate affective callousness from general emotional distress, generalized anxiety, and internalizing psychopathology:

• Internalizing Symptoms: In contrast to standard conduct problem scales that correlate positively with anxiety and depression, the ICU Callousness subscale demonstrates near-zero or negative correlations with trait anxiety and internalizing distress (r = -.08 to -.24), confirming that CU traits capture an emotionally blunted rather than a distressed antisocial profile.
• Reactive vs. Proactive Aggression: While general conduct problem measures correlate with both aggression types, structural regression models demonstrate that the ICU Callousness subscale uniquely predicts proactive, predatory aggression after controlling for reactive aggression (Fanti et al., 2009).

7.3. Predictive and Longitudinal Validity

Longitudinal investigations establish the ICU as a premier predictive biomarker for chronic delinquency and adverse developmental outcomes:

• Recidivism and Institutional Misconduct: In incarcerated adolescent cohorts, high ICU total scores predict violent re-offending, infractions during detention, and resistance to standard rehabilitation interventions over 12- to 36-month follow-up windows (Kimonis et al., 2014).
• Academic and Social Impairment: Longitudinal community studies (e.g., Ciucci et al., 2014; Moran et al., 2009) document that elevated ICU scores at age 7 or 8 uniquely predict bullying behaviors, school disciplinary actions, severe peer rejection, and academic disengagement at ages 12 through 16, independently of baseline ADHD or oppositional defiant disorder (ODD) symptoms.
• Physiological and Neurological Correlates: Laboratory validation paradigms confirm that youths scoring elevated on the ICU exhibit reduced startle reflex potentiation when viewing distress imagery, attenuated skin conductance reactivity during fear conditioning, and diminished fMRI BOLD response within the amygdala when processing fearful faces.

8. Reliability

The Inventory of Callous-Unemotional Traits demonstrates well-established reliability parameters across its multiple informant formats and demographic groups, though subscale variations provide important nuances for psychometricians.

8.1. Internal Consistency

Extensive psychometric investigations across international translations (e.g., English, German, Italian, Dutch, Greek, Spanish, Chinese) report robust internal consistency for the total scale, with variation across the three constituent subscales:

• Total ICU Scale: Cronbach’s alpha (α) coefficients consistently range from .77 to .89 across self-, parent-, and teacher-report versions in adolescent and child populations (Essau et al., 2006; Kimonis et al., 2008; Roose et al., 2010). McDonald’s omega hierarchical (ω_h) values typically exceed .80, indicating a dominant common latent source of variance.
• Callousness Subscale: Exhibits good internal consistency, with α values ranging between .70 and .82.
• Uncaring Subscale: Demonstrates acceptable to good reliability, with α values between .73 and .84.
• Unemotional Subscale: Frequently exhibits lower internal consistency across studies, with α coefficients commonly falling between .53 and .68. Psychometric research indicates that this lower alpha is partly attributable to its brief length (5 items) and the presence of reverse-scored items that introduce systematic method variance.

8.2. Test-Retest Reliability and Longitudinal Stability

Temporal stability evaluations demonstrate that callous-unemotional traits operate as stable, trait-like personality dimensions across developmental epochs:

• Short-term test-retest reliability across 2- to 4-week intervals yields intraclass correlation coefficients (ICCs) between .82 and .90.
• Medium-to-long-term stability across 6-month to 1-year intervals yields stability coefficients ranging from .60 to .75 in adolescent community and juvenile offender samples, demonstrating remarkable trait stability across the pubertal transition.

8.3. Cross-Informant Agreement

In accordance with standard developmental psychopathology assessment literature, inter-rater concordance between parent-, teacher-, and youth-reports is modest to moderate (correlations ranging from r = .25 to .45). Parent-teacher agreement is consistently higher than youth-parent agreement, highlighting the critical necessity of multi-informant assessment to capture contextual differences in the manifestation of callous-unemotional behaviors.

9. Factor Analysis

The structural topology of the Inventory of Callous-Unemotional Traits has been the subject of extensive empirical evaluation using both Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA), leading to a consensus structural model.

9.1. The Three-Factor Correlated and Hierarchical Models

In the seminal psychometric validation conducted by Essau, Sasagawa, and Frick (2006) among a large German community sample of adolescents (N = 1,443), CFA tested several competing structural configurations:

• A single general psychopathy factor model.
• An orthogonal three-factor model.
• A three-factor correlated model.
• A hierarchical (higher-order) model featuring one overarching general Callous-Unemotional factor superordinate to three primary factors: Callousness, Uncaring, and Unemotional.

The hierarchical model provided an excellent fit to the data across both male and female cohorts (Comparative Fit Index [CFI] > .90, Root Mean Square Error of Approximation [RMSEA] ≤ .05). This factor structure was subsequently confirmed in juvenile offender samples (Kimonis et al., 2008), Dutch adolescent samples (Roose et al., 2010), and Italian school samples (Ciucci et al., 2014).

9.2. Bifactor Structural Models and Method Variance

More recent psychometric evaluations employing advanced structural equation modeling have demonstrated that a bifactor model frequently outperforms the higher-order hierarchical model. In the bifactor formulation, every item loads directly onto a general, overarching “Callous-Unemotional” dimension, while simultaneously loading onto orthogonal specific group factors (Callousness, Uncaring, Unemotional). This bifactor approach has clarified that:

• The general CU dimension accounts for the majority of the common variance (> 65–75%), validating the clinical interpretation of the ICU Total Score.
• Method effects stemming from item wording directionality are present. Several items in the Uncaring subscale are positively worded (prosocially phrased and reverse scored), which can produce a minor method-artifact factor if not modeled properly.

9.3. Fit Indices Across Informants and Preschool Adaptations

Model fit indices across extensive international samples consistently meet established psychometric standards:

• Confirmatory Fit Statistics: Typical CFA fit statistics for the bifactor/three-factor model yield χ²/df < 2.5, CFI between .91 and .95, Tucker-Lewis Index (TLI) between .90 and .94, and RMSEA between .038 and .055, with Standardized Root Mean Square Residual (SRMR) < .05.
• Preschool Downward Extensions: Ezpeleta et al. (2012) tested the parent-report version in preschool children aged 3 and 4 years, demonstrating that the three-factor structure remains invariant even in early childhood, capturing nascent manifestations of affective deficits.
• Short Forms: To reduce administration burden in large epidemiological and forensic screenings, researchers have derived shortened 11-item and 12-item variants (e.g., ICU-12, Ray et al., 2016; Kimonis et al., 2013). These brief versions eliminate psychometrically unstable unemotional items, retaining the strongest callous and uncaring items while preserving total score predictive validity.

10. Instrument / Measurement Tool

The Inventory of Callous-Unemotional Traits is a structured, standardized behavioral rating scale. Below are its operational parameters and clinical administration characteristics:

• Instrument Type: Standardized multi-informant psychological rating inventory.
• Format Variants: Available in five distinct validated iterations:
  • Youth Self-Report: Calibrated for adolescents aged 11 to 18 years.
  • Parent-Report (Youth Version): Completed by primary caregivers of youth aged 6 to 18.
  • Teacher-Report (Youth Version): Completed by educators or school psychologists for students aged 6 to 18.
  • Parent-Report (Preschool Version): Downward adaptation for children aged 3 to 5.
  • Teacher-Report (Preschool Version): Downward adaptation for day-care providers and preschool teachers.
• Item Count: 24 statements distributed across three constituent subscales:
  • Callousness Subscale: 11 items (Items 2, 4, 7, 8, 9, 10, 11, 12, 18, 20, 21).
  • Uncaring Subscale: 8 items (Items 3, 5, 13, 15, 16, 17, 23, 24).
  • Unemotional Subscale: 5 items (Items 1, 6, 14, 19, 22).
• Response Format: 4-point Likert scale scored from 0 to 3:
  • 0 = Not at all true
  • 1 = Somewhat true
  • 2 = Very true
  • 3 = Definitely true
• Administration Duration: Approximately 5 to 10 minutes per informant.
• Scoring and Transformation Rules:
  • Reversed Scoring: 12 of the 24 items are positively phrased prosocial statements that must be reversed prior to computing subscale and composite scores (i.e., 0 becomes 3, 1 becomes 2, 2 becomes 1, 3 becomes 0). The reverse-scored items are: 1, 3, 5, 8, 13, 14, 15, 16, 17, 19, 23, and 24.
  • Composite Summation: Subscale raw scores are derived by summing the items within each respective dimension. The Total ICU Score is calculated by summing all 24 items, yielding a potential score range from 0 to 72, with higher scores reflecting greater callous-unemotional pathology.
  • Normative Interpretation: Raw scores are typically converted to percentile ranks and standard T-scores (Mean = 50, SD = 10) based on normative reference tables stratified by age, gender, and informant source.

11. Permissions & Fee and Test Year

The Inventory of Callous-Unemotional Traits was developed by Paul J. Frick in 2004. Unlike many commercially restricted psychological test batteries, Dr. Frick established the ICU as an open-access, non-commercial rating instrument to facilitate global empirical research and public clinical application.

• Publication Year: 2004 (Initial formal standardization and release from the Department of Psychology, University of New Orleans).
• Licensing and Research Use: The ICU is distributed free of charge for non-commercial academic, research, and non-profit clinical purposes. Researchers and clinicians are permitted to download, administer, and reproduce the forms without paying royalty or licensing fees.
• Commercial and Proprietary Use: Commercial redistribution, inclusion within proprietary fee-for-service digital assessment platforms, or use within profitable enterprise settings requires written authorization from Dr. Paul J. Frick.
• Official Repository: The full spectrum of multi-informant forms, standardized scoring keys, translations into over 20 languages, and normative tables are maintained and accessible via Dr. Frick’s academic research repository at Louisiana State University (LSU Developmental Psychopathology Lab).

12. References

Below are primary foundational references documenting the conceptual development, psychometric properties, and clinical validation of the ICU:

• Ciucci, E., Baroncelli, A., Franchi, M., Golmaryami, F. N., & Frick, P. J. (2014). The association between callous-unemotional traits and behavioral and academic adjustment in children: Further validation of the Inventory of Callous-Unemotional Traits. Journal of Psychopathology and Behavioral Assessment, 36(2), 189–200. https://doi.org/10.1007/s10862-013-9384-z
• Essau, C. A., Sasagawa, S., & Frick, P. J. (2006). Callous-unemotional traits in a community sample of adolescents. Assessment, 13(4), 454–469. https://doi.org/10.1177/1073191106287354
• Ezpeleta, L., de la Osa, N., Granero, R., Penelo, E., & Domènech, J. M. (2012). Inventory of Callous-Unemotional Traits in a community sample of preschoolers. Journal of Clinical Child and Adolescent Psychology, 42(1), 91–105. https://doi.org/10.1080/15374416.2012.738451
• Fanti, K. A., Frick, P. J., & Georgiou, S. (2009). Linking callous-unemotional traits to instrumental and non-instrumental forms of aggression. Journal of Psychopathology and Behavioral Assessment, 31(4), 285–298. https://doi.org/10.1007/s10862-008-9111-3
• Frick, P. J. (2004). The Inventory of Callous-Unemotional Traits (ICU). Unpublished rating scale, University of New Orleans.
• Jones, A. P., Happé, F. G., Gilbert, F., Burnett, S., & Viding, E. (2010). Feeling, caring, knowing: Different types of empathy deficit in boys with psychopathic tendencies and autism spectrum disorder. Journal of Child Psychology and Psychiatry, 51(11), 1188–1197. https://doi.org/10.1111/j.1469-7610.2010.02280.x
• Kimonis, E. R., Fanti, K. A., Goldweber, A., Marsee, M. A., Frick, P. J., & Cauffman, E. (2014). Callous-unemotional traits in incarcerated adolescents. Psychological Assessment, 26(1), 227–237. https://doi.org/10.1037/a0034789
• Kimonis, E. R., Frick, P. J., Skeem, J. L., Marsee, M. A., Cruise, K., Muñoz, L. C., & Morris, A. S. (2008). Assessing callous-unemotional traits in adolescent offenders: Validation of the Inventory of Callous-Unemotional Traits. International Journal of Law and Psychiatry, 31(3), 241–252. https://doi.org/10.1016/j.ijlp.2008.04.002
• Moran, P., Rowe, R., Flach, C., Briskman, J., Ford, T., Maughan, B., Scott, S., & Goodman, R. (2009). Predictive value of callous-unemotional traits in a large community sample. Journal of the American Academy of Child & Adolescent Psychiatry, 48(11), 1079–1084. https://doi.org/10.1097/CHI.0b013e3181b766a9
• Ray, J. V., Frick, P. J., Thornton, L. C., Steinberg, L., & Cauffman, E. (2016). Positive and negative item bias in the Inventory of Callous-Unemotional Traits. Psychological Assessment, 28(9), 1094–1103. https://doi.org/10.1037/pas0000244
• Roose, A., Bijttebier, P., Decoene, S., Claes, L., & Frick, P. J. (2010). Assessing the affective features of psychopathy in adolescence: A further validation of the Inventory of Callous and Unemotional Traits. Assessment, 17(1), 44–57. https://doi.org/10.1177/1073191109344153

13. Items of the Scale