The Self-Report Psychopathy (SRP) scale was designed by Robert D. Hare as a self-report version of his Psychopathy Checklist (PCL) and its revision (PCL-R). Originally created using correctional and forensic populations, the PCL-R is a 20-item construct rating scale that conceptualizes psychopathy as a superordinate dimensional construct composed of four correlated factors: interpersonal (glibness/superficial charm, grandiose sense of self-worth, pathological lying, conning/manipulative), affective (lack of remorse or guilt, shallow affect, callous/lack of empathy, failure to accept responsibility for actions), lifestyle (need for stimulation/proneness to boredom, parasitic lifestyle, lack of realistic long-term goals, impulsivity, irresponsibility), and antisocial (poor behavioral controls, early behavior problems, juvenile delinquency, revocation of conditional release, criminal versatility). Based on a structured interview and file review, PCL-R items are scored on a 0–2 ordinal scale with a recommended diagnostic cutoff score of 30 or above for research and forensic purposes.
The PCL-R is considered the international standard for the assessment of psychopathy and helped to significantly advance understanding of the construct by providing a common metric for researchers and clinicians. However, as with any psychiatric interview, the PCL-R requires extensive training and skilled clinicians or researchers to administer it. Thus, the time and cost to train and administer the PCL-R, along with the low prevalence of clinically diagnostic psychopathy in the general population (approximately 1%), lead it to be less practical for non-forensic settings. In addition, certain PCL-R items that are relevant in offender settings (e.g., revocation of conditional release, criminal versatility) may not be appropriate for community samples. For research in the general population, Hare and colleagues developed the SRP. This article focuses on the development and utility of the SRP, as well as its strengths and critique of other psychopathy self-report measures.
SRP Development
Hare developed the initial versions of both the SRP and the PCL in 1985 after finding that early measures used to assess psychopathy (e.g., Psychopathic Deviate scale from the Minnesota Multiphasic Personality Inventory and the Socialization scale from the California Psychological Inventory) had weak associations with each other and the early PCL. The SRP was developed using standard item reduction procedures to identify items related to psychopathy. Despite developing the initial SRP in the same theoretical framework as the PCL, the agreement between the two instruments was modest. To refine the SRP, Hare and colleagues developed the SRP-II in 1991 to reflect the two-factor structure of the PCL-R. Factor 1 of the PCL-R includes the interpersonal and affective components of psychopathy, and Factor 2 combines lifestyle and antisocial factors. To reflect the PCL-R changes, the SRP-II was expanded to a comprehensive 60-item measure with 31 items specifically designed to capture the two-factor structure. The validity of the SRP-II was bolstered by robust positive correlations with the PCL-R in both clinical and forensic samples. In non-forensic settings, Delroy Paulhus and his colleagues found that SRP-II total scores correlated positively with a variety of antisocial behavioral (e.g., delinquency) and personality (e.g., disagreeableness, promiscuous sexual attitudes) variables.
Despite these positive findings, Paulhus and his colleagues found limitations in the SRP-II. One limitation was that the factor structure did not mirror that of the PCL-R. Instead, the first factor was a combination of antisocial behavior, impulsivity, and interpersonal manipulation, which Paulhus termed impulsive trouble-making; the second factor, emotional stability, contained items pertaining to low anxiety and high self-confidence. The latter factor corresponded to low scores on the neuroticism factor of the Five Factor Model of personality.
To address these limitations, Paulhus, Hare, and colleagues refined the SRP-II. They suggested that the inclusion of anxiety-related items and the absence of items related to antisocial behavior were major reasons for the discrepant factor structure. It became evident that (low) anxiety was not an essential feature of SRP psychopathy. Similarly, research with other SRP measures with anxiety-related items (e.g., the Minnesota Temperament Inventory) found that they did not covary meaningfully with core psychopathy traits, thus warranting their removal. In addition, meta-analytic research has shown that low constraint and poor threat detection are more fundamental to psychopathy than low anxiety. Another limitation of the SRP-II was that it did not reflect the four-factor model of psychopathy, initially proposed in the second edition of the PCL-R in 2003. As Hare and Craig Neumann have documented, there is extensive evidence for the four-factor model based on behavioral, genetic, longitudinal, and latent variable modeling research.
To address these issues, Paulhus and colleagues removed items related to anxiety and added several items tapping into the four dimensions of psychopathy, which resulted in a 77-item experimental measure referred to as the SRP-E. Research with the SRP-E found a correlated four-factor structure: with factors labeled interpersonal manipulation, criminal tendencies, erratic lifestyle, and callous affect. This four-factor model mirrored the four-factor model of the PCL-R as well as scales developed in the same theoretical network such as the screening and youth versions of the PCL-R. Further refinement of the SRP-E led to the development of the modern 64-item SRP-III, which can also be reliably administered as a short 29-item form called the SRP-SF, developed via model-based measurement theory. Despite some minor differences, the SRP-III and the SRP-SF are strongly intercorrelated (e.g., r = .92), show significant overlap in predicting relevant variables related to psychopathy, and both replicate the PCL-based four-factor latent variable model of psychopathy.
Drawing on the SRP-III and SRP-SF research, the SRP-4 was published in 2016. The SRP-4 comes with an in-depth manual that provides norms based on large community, college, and offender samples; scoring procedures; and a comprehensive body of construct validation evidence for both the full and short form versions. Although the total scores on all versions of the SRP yield virtually identical results, only the SRP-4 and SRP-III have the four-factor structure that permits scoring of all four subscales commensurate with the PCL-R.
Strengths
The modern SRP, a self-report analogue of the PCL-R, has several notable attributes. A major strength is the mathematically strong and theoretically sound latent structure of the measure. On a practical level, this means that responses to the SRP items are highly discriminating of persons who are low versus elevated on psychopathic propensities. In addition, the four-factor structure is invariant across gender and provides a model that can capture psychopathic features across diverse samples (i.e., student, community, offender). Moreover, based on a mega-world sample of 33,016 individuals, the four-factor structure of the SRP showed excellent fit, suggesting that it can be used to assess psychopathic personality across the globe. Furthermore, the SRP has demonstrated strong relationships with the Youth Psychopathic Traits Inventory, measures of dark personality traits, and a psychopathy self-report based on the Five Factor Model of personality (Elemental Psychopathy Assessment), indicating that there is a sound theoretical framework surrounding the SRP and this set of measures.
Additional construct validity comes from the fact that elevated SRP scores are associated with relevant external correlates. Specifically, the SRP has been found to be predictive of violence and serious offending behavior, above and beyond other indicators of offending risk. In addition, elevated SRP scores are associated with less empathetic concern and amoral reasoning. Furthermore, the SRP is significantly linked with reduced amygdala activation and volume, an area of the brain associated with emotional processing, in concordance with previous neuroimaging psychopathy research on forensic samples. In the general population, researchers have also found that elevated SRP scores are associated with behavioral indicators of scholastic cheating, fraud, bullying, and drug use. These findings illustrate that SRP traits predict critical external variables associated with psychopathy.
Critique of Other Popular Self-Report Measures of Psychopathy
Since the development of the first SRP, several self-report scales putatively measuring psychopathy have emerged, though questions have been raised regarding their theoretical basis and the items used in the scales. In contrast to the concordance between the SRP, the PCL scales, and other psychopathy assessments (e.g., Elemental Psychopathy Assessment, Youth Psychopathic Traits Inventory), the Psychopathic Personality Inventory (PPI) and the Triarchic Psychopathy Measure (TriPM) have been derived from another theoretical conceptualization of psychopathy that emphasizes the role of low anxiety. While it may be suggested that these measures have construct validity based on their associations with various external correlates, the precise nature of these associations is ambiguous due to evidence of problematic factor structures and the paucity of rigorous research examining latent structure and item-to-factor relations. As the PCL scales have accumulated extensive validation, it is important to consider the associations the PPI and TriPM have with the PCL-R as well as the coherence of the latent structure of these measures.
Concerns about the structure and construct validity of the PPI and its revision have been raised. The PPI is a 187-item measure consisting of eight subscales, seven of which are thought to be loaded onto two factors termed fearless dominance (FD) and self-centered impulsivity, which are believed to be associated with Factor 1 and Factor 2 of the PCL-R, respectively. However, FD and PCL-R Factor 1 share only 4–5% of variance, the FD factor has demonstrated opposing relationships with a number of external correlates, and the scales that comprise FD lack sensitivity in discriminating individuals with psychopathy from those without psychopathy from community and offender samples. In addition, researchers have found that the subscales of the PPI lack item homogeneity and the two-factor model to be an untenable model. Taken together, the psychometric properties of the PPI introduce ambiguity to its interpretation, which attenuates the validity of the instrument.
The TriPM has demonstrated notable statistical issues that warrant attention. A 58-item self-report measure, the TriPM, conceptualizes psychopathy as a compound condition that emerges from interactions among three trait domains: boldness, disinhibition, and meanness. Although these three domains have been proposed to be elemental building blocks of psychopathy, item-level analyses have called this into question. Researchers have found poor fit for the TriPM three-factor structure due to the presence of subfactors nested within the three trait domains, with differential correlations among the subfactors and with external correlates. This pattern indicates that correlations between the three factors of the TriPM and other constructs will be imprecise due to the lack of item homogeneity and differential subfactor associations. With regard to construct validity, the TriPM domains evidence low to moderately low correlations with multiple facets of the PCL-R except the affective domain, which correlates with none of the TriPM traits. This pattern illustrates that the three proposed TriPM domains are multidimensional and may not assess psychopathy with the specificity demonstrated by PCL-R four-factor model.
Limitations and Future Directions
The SRP may have some limitations. Self-report measures can be subjected to dishonest responding or lack of insight. However, studies have found that psychopaths do not engage in impression management when completing self-report measures with no secondary gain. Future research should directly compare the statistical properties of the SRP with other SRP measures to see whether they are assessing the same construct. The SRP, with its robust relationship with the PCL-R and mathematically sound latent structure, is an ideal research tool for investigating psychopathy in a wide variety of samples.
References:
- Neumann, C. S., Hare, R. D., & Pardini, D. A. (2015). Antisociality and the construct of psychopathy: Data from across the globe. Journal of Personality, 83, 678–692. doi:10.1111/jopy.12127
- Neumann, C. S., Uzieblo, K., Grombez, G., & Hare, R. D. (2013). Understanding the Psychopathic Personality Inventory (PPI) in terms of the unidimensionality, orthogonality, and construct validity of PPI-I and -II. Personality Disorders: Theory, Research, and Treatment, 4, 77–79. doi:10.1037/a0027196
- Paulhus, D. L., Neumann, C. S., & Hare, R. D. (2016). Manual for Self-Report Psychopathy (SRP) scales (4th ed.). Toronto, Canada: Multi-Health Systems.
- Shou, Y., Sellbom, M., & Xu, J. (2017). Psychometric properties of the Triarchic Psychopathy Measure: An item response theory approach. Personality Disorders: Theory, Research, and Treatment, 9(3), 217–227. doi:10.1037/per0000241