Psychopathic personality disorder comprises a distinct collection of deviant affective, interpersonal, and behavioral features. Results of psychopathy testing can sway life-altering decisions for the examinee, including granting of parole, outcome in sexually violent predator civil commitment trials, gaining access to treatment, and even being sentenced to death. Because the disorder is strongly predictive of violent and general criminal recidivism, it has had an impact on correctional theory, public policy, and legal decision making on an international scale. Although psychopathy is one of the most researched disorders within the field of psychology and law, until recently most empirical investigations involved White male prisoners and forensic psychiatric patients in North America. Given that assessments of psychopathy occur regularly and as a matter of law in many contexts, it is crucial to ascertain the extent to which the primarily White male research base generalizes to other relevant populations, such as individuals of other ethnic backgrounds. Research indicates that the Psychopathy Checklist-Revised (PCL-R) measures the disorder in an unbiased way across ethnocultural groups within a single culture (White vs. Black within North America, Scottish vs. English and Welsh within the United Kingdom). However, there is some evidence of cross-national metric invariance: That is, North Americans obtain PCL-R scores that are 2 to 3 points higher than those of Europeans, given equivalent levels on the underlying trait of psychopathy. Moreover, whereas there is little cross-cultural bias in ratings of affective symptoms of psychopathy, bias does exist for ratings of the interpersonal and behavioral symptoms. In light of the substantial weight placed on PCL-R results when important decisions about individual liberties are made, it is crucial that cross-cultural research continue, preferably using more culturally informed classifications of ethnic status and with varied samples, including women and girls and individuals outside of Europe and North America. Such research may also shed light on the etiological bases underpinning the divergent manifestations of psychopathy.
Ethnicity refers to differences in culture and ancestry. In social sciences research, the term race is often used interchangeably with ethnicity, although the former term generally denotes more fine-grained genetic differences. In psychopathy research, race typically is based on self-identification rather than biological or genetic classification. In this research paper, the term ethnicity is used to refer to ethnic, cultural, and racial groups as conceptualized within the relevant research literature on ethnicity and psychopathy. Three key issues have been addressed within this research paper base: (a) the degree to which similar patterns of associations between external correlates of psychopathy are observed across groups, (b) measurement generalization across groups, and (c) mean levels of psychopathic traits across groups.
External Correlates of Psychopathy across Ethnic Groups
For psychopathy to be construed as a universal syndrome, the correlates of psychopathy should be similar across ethnic groups. The correlates that, perhaps, are of greatest interest include antisocial behavior and violence. Results of studies on adult criminal offending in the community conducted outside North America and with non-Whites in North America are similar in that psychopathy is inversely related to age of onset of criminal behavior and that individuals scoring high on psychopathic traits commit more violent and nonviolent crime and are more versatile in their crime patterns. Meta-analytic evidence indicates, however, that psychopathy is a weaker correlate of violent recidivism among more ethnically diverse samples of juvenile offenders relative to primarily White samples. Pertaining to institutional aggression, meta-analytic results indicate that the country under study matters: Although the predictive utility of psychopathy for broad categories of institutional misbehavior is good, its relation to violent infractions in the United States is substantially smaller than in non-U.S. institutions. One explanation for this disparity is the potentially greater ethnic heterogeneity in U.S. samples.
Another class of external correlates of psychopathy comprises psychophysiological and behavioral variables that exhibit reliable patterns in North American samples. The few cross-cultural studies investigating such variables offer inconsistent findings. Additionally, studies of performance on laboratory tasks that assess cognitive and emotional processing in North America suggest that Whites and Blacks high on psychopathic traits may process information differently.
Studies conducted in North America and abroad on the association between psychopathy and major mental illness and personality disorders indicate similar patterns for comorbid psychiatric diagnoses and self-report personality traits. However, research investigating White and Black U.S. offenders suggests that members of these groups do not manifest the same patterns of correlations between psychopathy and self-report personality measures. Whereas the association between psychopathy and self-reported negative affect is similar for Blacks and Whites, associations between impulsivity and psychoticism are less consistent. The observed discrepancies suggest that mechanisms underlying psychopathy may differ for Blacks and Whites and may be influenced by genetic and sociocultural factors that vary across ethnic groups.
Measurement Generalization across Ethnic Groups
In contemporary research, psychopathy most often is operationalized vis-a-vis the PCL family of measures. Traditional psychometric evaluations indicate adequate reliability for the PCL-R among non-White adults as well as for adolescents of various ethnicities assessed with the youth version of the measure. To demonstrate cross-cultural equivalence of the PCL-R, it is also necessary to demonstrate that the factor structure of the measure is the same across ethnic groups (i.e., that the same items or symptoms cluster together). There is clear evidence of a replicable factor structure(s) among White and Black adult men in U.S. prisons; among White, Black, and Latino boys in the United States; and among European men (including men from Scotland and several continental European countries).
Cross-cultural equivalence in the case of the PCL-R also requires that the association between test scores and the latent trait of psychopathy be invariant across ethnic groups (metric invariance), which may be examined using item response theory (IRT). IRT confers several distinct advantages to investigations of cross-cultural disparities: Representative samples are not required, more detailed analysis of individual ratings can be provided, and a determination can be made regarding whether scores are measured on the same scale with different ethnic groups. An often-cited analogy that involves the measurement of temperature using Fahrenheit and Celsius degrees may help clarify the last point: Although both scales measure the same construct, comparisons are meaningless because they differ in zero points and scale increments. In the case of the PCL-R, metric variance across groups is problematic because different scores could express the same level of the latent trait of psychopathy (or, conversely, the same PCL-R score obtained by two groups would not represent the same underlying level of the disorder). In general, research using IRT methods indicates that the PCL-R may be used in an unbiased way with Blacks. However, there does appear to be evidence of metric invariance between North America and Europe (both in the United Kingdom and continental countries). Compared with North Americans, Europeans tend to obtain lower PCL-R total, factor, and item scores for the same level of the underlying trait of the disorder, thereby prompting some experts to recommend adjusting the diagnostic threshold of a total PCL-R score of 30 used in North America to 28 when used in Europe. The symptoms tapping the deficient affective experience seem to be the most diagnostic of psychopathy and are thought to be more stable across cultures compared with the interpersonal and behavioral features of the disorder. However, at extreme levels of psychopathy, the interpersonal symptoms may provide more diagnostic information (especially in the United Kingdom). Research indicates that these cross-national differences in psychopathy reflect genuine differences in the expression of the disorder, rather than raters’ perceptions of the psychopathic symptoms.
Differences in Levels of Psychopathic Traits
Because the generalizability of the measurement of PCL-R total scores across Blacks and Whites has been demonstrated, it is appropriate to use this instrument to investigate whether these groups differ in the extent to which they display psychopathic characteristics. Two large-scale meta-analyses have examined this issue for adults and adolescents. When differences between PCL-R total scores of Black and White adults from 21 studies were examined in the aggregate (with an overall sample size of 8,890 individuals), no reliable, meaningful differences in scores between the two groups were observed. When differences between total scores on the youth version of the measure of Black and White adolescents from 16 studies were averaged (with an overall sample size of 2,199), ratings of psychopathic characteristics were significantly higher among Black youth. Importantly, however, the overall magnitude of this effect was small and corresponded to about 1.5 points on the 40-point psychopathy scale. There was considerable heterogeneity in the effect sizes (associations between scores and ethnicity) in both studies, but no clear moderators of the relation between ethnicity and psychopathy scores were identified.
Explaining Cross-Group Differences in Psychopathy
Experts agree that a host of biological, psychological, and social factors likely contribute to the etiology of personality disorders. A major weakness in the psychopathy research in this area is that ethnic/racial categories are fairly simplistic, created on the basis of self-identification in the absence of a consideration of relevant variables (including biological, genetic, psychological, and social) that influence group membership. Substantial within-group heterogeneity exists regarding important dimensions such as acculturation, ethnic identity, socioeconomic status, and neighborhood characteristics, and these sources of heterogeneity present obstacles to pinpointing the etiological factors underlying any group differences that may be observed. Pertaining to psychopathy research, relying on simplistic classifications of ethnicity such as Black and White severely constrains the potential to identify more proximal causes of observed disparities in psychopathy. As but one example of the importance of considering how contextual factors that vary across ethnic groups may be critical in explaining socially deviant behavior, consider the example of living in a “bad” neighborhood. In a large-scale study in which more than 900 civil psychiatric patients were administered the screening version of the PCL-R and followed in the community for 1 year, the degree to which an individual’s neighborhood was disadvantaged (indexed by rates of public assistance, poverty, unemployment, managerial employment, vacant dwellings, female-headed households, and average household wage) was strongly associated with race (i.e., being Black was associated with living in a more disadvantaged neighborhood). Race retained little relation to psychopathy once neighborhood disadvantage was taken into account by statistical methods. In this study, of the 100+ risk factors for violence that were studied, psychopathy was the strongest predictor of community violence. Importantly, even after statistically taking into account factors such as psychopathy and race, the amount of concentrated poverty in participants’ neighborhoods still significantly predicted violence. Whereas race did predict violence when considered on its own, the effect of race alone in predicting violence disappeared after statistically controlling for neighborhood disadvantage. That is, regardless of whether participants were Black or White, those who lived in highly disadvantaged neighborhoods were more likely to be violent. Although further investigation clearly is needed, these results highlight the importance of investigating cultural and social processes that may influence psychopathic traits.
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