A taxometric analysis of psychopathic personality

Although a common assumption throughout much of the professional and popular literature is that psychopaths are qualitatively different from others, very few studies have examined the latent structure of psychopathy. Whether psychopathy is a discrete category or a continuous dimension may have implications for research on the assessment, etiology, and treatment of this disorder. This study examined the latent structure of psychopathy in a sample of 309 jail and prison inmates. Three taxometric procedures were used to analyze indicators drawn from the Psychopathic Personality Inventory (S. O. Lilienfeld & B. P. Andrews, 1996), a self-report instrument. Consistent with prior studies that used other measures of psychopathy, none of the analyses was consistent with a taxonic solution, suggesting that psychopathic personality may be best understood as existing on a continuum.     

A taxometric analysis of the MMPI-2 Depression scales

The MMPI (Hathaway & McKinley, 1943) and MMPI-2 (Butcher et al., 2001) have long been used as measures of psychopathology. Both clinicians and researchers have noted the widespread existence of negative affectivity on the MMPI and MMPI-2 that may elevate scale scores and eclipse the tests' ability to differentiate depression from other clinical disorders. Using taxometric analyses, in this study we sought to test directly whether the MMPI-2 depression scales could differentiate patients with depressive symptoms from patients with other disorders. A large psychiatric sample (N = 2,000) was utilized and analyses were run separately for men and women. Taxometric analyses did not find a MMPI-2 Depression scale cut point that categorizes patients with depressive symptoms from other patients. Rather, these findings support previous studies finding an underlying dimensionality of depression. We discuss implications for MMPI-2 scale use and depression nosology in light of these findings.     

Informing the continuity controversy: a taxometric analysis of depression

Researchers and practitioners have long debated the structural nature of mental disorders. Until recently, arguments favoring categorical or dimensional conceptualizations have been based primarily on theoretical speculation and indirect empirical evidence. Within the depression literature, methodological limitations of past studies have hindered their capacity to inform this important controversy. Two studies were conducted using MAXCOV and MAMBAC, taxometric procedures expressly designed to assess the underlying structure of a psychological construct. Analyses were performed in large clinical samples with high base rates of major depression and a broad range of depressive symptom severity. Results of both studies, drawing on 3 widely used measures of depression, corroborated the dimensionality of depression. Implications for the conceptualization, investigation, and assessment of depression are discussed.     

A taxometric analysis of actual Internet sports gambling behavior

This article presents findings from the first taxometric study of actual gambling behavior to determine whether we can represent the characteristics of extreme gambling as qualitatively distinct (i.e., taxonic) or as a point along a dimension. We analyzed the bets made during a 24-month study period by the 4,595 most involved gamblers among a cohort of 48,114 people using an Internet service to gamble on sporting events. We applied two taxometric procedures (i.e., MAMBAC and MAXCOV) to three indicators of betting behavior: total money lost, total number of bets, and total money wagered. The results fail to provide support for the view that the most involved Internet sports gamblers include a distinct category of gamblers. More research is necessary to clarify the similar features of recreational and extreme gamblers and the dimensions that scientists can use to measure these behaviors. Finally, we discuss the implications of these findings for clinical, research, and public policy activities.     

Envy and jealousy as discrete emotions: A taxometric analysis

Envy and jealousy may differ in kind or only by degree. In a study of emotion episodes recalled by 291 subjects, two forms of taxometric analysis were used to test between categorical and dimensional models of the two emotions. The two emotions yielded strong convergent evidence of discreteness, and commonly cooccurred. However, although subjects rated their episode to contain similar levels of envy and jealousy, both terms were equally correlated with the presence of envy features and neither term was correlated substantially with the presence of jealousy features. Implications ar drawn for the study of categorical distinctions between emotions, and for the relation between emotions and emotion terms.The authors would like to thank Tammy Carter for assistance with data collection.     

Confirming the latent structure and base rate of schizotypy: a taxometric analysis.

Meehl's (1962, 1990) model of schizotypy and the development of schizophrenia implies that the structure of liability for schizophrenia is dichotomous and that a "schizogene" determines membership in a latent class, or taxon (Meehl & Golden, 1982). The authors sought to determine the latent structure and base rate of schizotypy. They applied Meehl's (1973; Meehl & Golden, 1982) MAXCOV-HITMAX taxometric analytic procedures to a subset of items from the Perceptual Aberration Scale (PAS; Chapman, Chapman, & Raulin, 1978), a prominent psychometric index of schizotypy, derived from a randomly ascertained nonclinical university sample (N = 1,093). The results, in accordance with Meehl's conjectures, strongly suggest that schizotypy, as assessed by the PAS, is taxonic at the latent level with a general population taxon base rate of approximately .10.     

A taxometric analysis of the latent structure of psychopathy: evidence for dimensionality

The taxonomic status of psychopathy is controversial. Whereas some studies have found evidence that psychopathy, at least its antisocial component, is distributed as a taxon, others have found that both major components of psychopathy-callousness/unemotionality and impulsivity/antisocial behavior-appear to distribute as dimensions and show little evidence of taxonicity. In the present study, recent advances in taxometric analysis were added to P. Meehl's (1995) multiple consistency tests strategy for assessing taxonicity, and they were applied to Psychopathy Checklist-Revised (R. D. Hare, 2003) ratings of 4,865 offenders sampled from multiple forensic settings. The results indicated that both the individual components of psychopathy and their interface are distributed dimensionally. Both the implications of these results for research in psychopathy and the integration of these findings with previous taxometric studies of psychopathy are discussed.     

Hedonic capacity and schizotypy revisited: a taxometric analysis of social anhedonia

P. E. Meehl (1962) originally conjectured that hedonic capacity was an indicator of the latent class or taxon of schizotypy. However, P. E. Meehl (1989, 1990) subsequently diminished the role of hedonic capacity in his theory, indicating that hypohedonia is one of a dozen normal-range (nontaxonic) individual-differences factors that may potentiate the expression of schizophrenia. This dimensional-only view of hedonic capacity was tested by applying taxometric procedures to the Revised Social Anhedonia Scale (RSAS; M. L. Eckblad, L. J. Chapman, J. P. Chapman, & M. Mishlove, 1982) in a sample of college students (N = 1,526). Analyses indicated that the construct measured by the RSAS is taxonic in nature with a base rate approximating .10. These data are interpreted in the context of other findings suggesting that social anhedonia is an indicator of schizotypy.     

A taxometric study of the Adult Attachment Interview

This study is the first to examine the latent structure of individual differences reflected in the Adult Attachment Interview (AAI; C. George, N. Kaplan, & M. Main, 1985), a commonly used and well-validated measure designed to assess an adult's current state of mind regarding childhood experiences with caregivers. P. E. Meehl's (1995) taxometric methods (i.e., MAXCOV-HITMAX) were applied to data from 504 AAIs. Analyses revealed that the variation underlying secure versus dismissing states of mind was more consistent with a dimensional than a taxonic model. (Taxometric analyses of preoccupation were indeterminate.) In addition, variation in secure adults' (n=278) reports about their early experiences revealed little evidence for qualitative groups of earned- and continuous-secures. Rather, the inferred life experiences of secure adults appeared to be distributed continuously. Findings are discussed in terms of their theoretical implications regarding the phenomenon of earned-security specifically and variation underlying secure and insecure states of mind more generally. The consequences of these analyses for AAI reliability training and coding are also explored.     

The latent structure of social anxiety disorder and the performance only specifier: a taxometric analysis

Social anxiety disorder (SAD) is often treated as a discrete diagnostic entity that represents a naturally occurring class, though empirical evidence largely supports a dimensional conceptualization of social fears. Further, the inclusion of a “performance only” specifier in the DSM-5 implies that individuals who experience intense social anxiety exclusively in performance situations are distinct from those with broader social fears. The purpose of the present research was to examine the latent structure of SAD and the DSM-5 “performance only” specifier in a large nonclinical sample (n = 2019). Three taxometric procedures (MAXCOV, MAMBAC, and L-Mode) were applied to indicators derived from two commonly used measures of social anxiety. Results yielded convergent evidence indicating that social anxiety exhibits a dimensional latent structure. Further, social performance anxiety demonstrates continuous relationships with milder social fears, suggesting that the “performance only” specifier may not represent a discrete entity. The implications of these findings for the assessment, diagnosis, classification, and treatment of social anxiety are discussed.     

A taxometric analysis of cognitive and neuromotor variables in children at risk for schizophrenia

A taxometric model was applied to detect a subgroup or taxon of children conjectured to be at highest risk for developing schizophrenia or related disorders in a sample of offspring of schizophrenic, depressed, and normal parents. Measures of cognitive and neuromotor performance in childhood were used as indicator tests in the analyses. A taxon consisting chiefly of children of schizophrenic parents was detected. Forty-seven percent of those children were assigned to the taxon, compared with 16% of the children of depressed parents and 4% of the children of normal parents. Assignment to the taxon is assessed in relation to the current functional status of the subjects in young adulthood.     

Psychopathic, not psychopath: taxometric evidence for the dimensional structure of psychopathy

Although psychopathy is frequently regarded as qualitatively distinct from other conditions, relatively little research has examined whether psychopaths represent a distinct class of individuals. Using a sample of 876 prison inmates and court-ordered substance abuse patients who were administered the Psychopathy Checklist-Revised (R. D. Hare, 2003), the authors examined the latent structure of psychopathy using several taxometric procedures developed by Meehl and colleagues (P. E. Meehl & L. J. Yonce, 1994; N. G. Waller & P. E. Meehl, 1998). The results across these procedures offer no compelling support for the contention that psychopathy is a taxonic construct and contradict previous reports that psychopathy is underpinned by a latent taxon. The authors discuss the theoretical, public policy, and practice-level implications of these findings.     

A taxometric investigation of the latent structure of worry

Researchers have described 2 types of worriers, normal and pathological, who differ in the frequency, intensity, and controllability of their worry experiences. Although normal and pathological worry are generally treated as separate though related phenomena, no study has tested for separateness against the alternative hypothesis that all worry exists along a single dimension. In the present study, worry ratings of 1,588 college students were submitted to taxometric procedures designed to evaluate latent structure. Results provided evidence for the dimensionality of worry. These findings suggest that generalized anxiety disorder (GAD), whose central feature is worry, may also be quantitatively rather than qualitatively different from normal functioning. The authors argue that a focus on normal and pathological extremes has constrained the study of worry phenomena and that dimensional conceptualization of worry may significantly enhance understanding of both worry and GAD.     

Detecting latent taxa: Monte Carlo comparison of taxometric, mixture model, and clustering procedures

A Monte Carlo evaluation of four procedures for detecting taxonicity was conducted using artificial data sets that were either taxonic or nontaxonic. The data sets were analyzed using two of Meehl's taxometric procedures, MAXCOV and MAMBAC, Ward's method for cluster analysis in concert with the cubic clustering criterion and a latent variable mixture modeling technique. Performance of the taxometric procedures and latent variable mixture modeling were clearly superior to that of cluster analysis in detecting taxonicity. Applied researchers are urged to select from the better procedures and to perform consistency tests.     

Categories and continua: a review of taxometric research

The taxometric procedures developed by Paul Meehl and his colleagues have been used in a large body of research seeking to distinguish between categorical and continuous models of latent variables. In this article the authors survey taxometric studies of psychopathological, personality, and other variables and draw conclusions about the taxonicity of latent variables in these domains. In addition, the authors review research on the validation and refinement of taxometric methods and make proposals for improving the application of taxometric research. The authors consider questions that remain about the conceptual status of taxometrics and raise new ones. They show that taxometric methodology has made an accelerating number of contributions to psychological research, has resolved several longstanding controversies, and has challenged some entrenched theoretical assumptions in differential psychology. Moreover, they contend that the research possibilities that it affords have yet to be fully exploited.     

A taxometric study of the Center for Epidemiological Studies Depression Scale

The authors assessed the latent structure of depressive symptoms as measured by the Center for Epidemiological Studies Depression Scale (CES-D; L. S. Radloff, 1977). By using taxometric procedures, the authors conducted analyses of CES-D data obtained from a large college student population. These procedures incorporated strategies for interpreting analyses of skewed indicators and small putative taxa. The authors hypothesized that CES-D total scores would be represented as a dimension, with a taxonic distribution of a factor incorporating somatic symptoms. Results indicated that all CES-D factors, including the factor composed of somatic complaints, were dimensional. Administration of the Diagnostic Interview Schedule-IV (L. N. Robins, L. Marcus, & W. Reich, 1996) to one quarter of the participants indicated that the CES-D was effective in identifying cases of current or recent clinical depression. Evidence of the dimensionality of CES-D indicators in a student population is consistent with a continuity view of depressive symptoms.     

Continuity and discontinuity models of bulimia nervosa: a taxometric investigation

Past research evaluating the continuity and discontinuity models of bulimia has produced inconclusive results. In the current study, we performed a taxometric analysis of bulimia nervosa using means above minus below a sliding cut and maximum covariance analysis with a sample of women diagnosed with bulimia nervosa (n = 201) or women college students (n = 412). Indicators were derived from the Bulimia Test--Revised and the Eating Attitudes Test--26, and both a mixed sample and the nonclinical sample were analyzed. With both taxometric methods and both mixed and nonclinical samples, results were consistently suggestive of a latent taxon for bulimia. These results challenge a dimensional model of bulimia nervosa.     

A taxometric analysis of MMPI-2 Infrequency scales [F and F(p)] in clinical settings

The typology of overreporting, which is a deliberate attempt to amplify symptoms, simulate psychopathology, or understate coping capacities, was examined using taxometric procedures with Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Infrequency scales [F and F(p)] in psychiatric inpatient and Veterans Affairs (VA) medical center treatment settings. Overreporting was identified as a taxon using several taxometric procedures, and the multiple estimates of the taxon base rate were consistent within each sample. Mean base-rate estimates were .27 and .19 for the psychiatric inpatient and VA medical center settings, respectively. Overall classification rates ranged from .80 to .97 across the 2 settings, which supports the use of F and F(p) in the identification of overreporting on the MMPI-2 in psychiatric inpatient and VA medical center settings.     

A taxometric analysis of the Psychopathy Checklist: Screening Version (PCL:SV): further evidence of dimensionality

A taxometric analysis of the Psychopathy Checklist: Screening Version (PCL:SV; S. D. Hart, D. N. Cox, & R. D. Hare, 1995) was performed on a group of 2,250 male and female forensic/psychiatric patients and jail/prison inmates. The 4 PCL:SV facet scores (Interpersonal, Affective, Impulsive Lifestyle, Antisocial Behavior) served as indicators in this study, and the data were analyzed with 3 principal taxometric procedures--mean above minus below a cut, maximum eigenvalue, and latent mode factor analysis. The results show evidence of dimensional structure on the PCL:SV in the full sample as well as in all 8 subsamples (men, women, Whites, Blacks, hospital patients, jail/prison inmates, file review with an interview, file review without an interview). These findings corroborate recent taxometric research on the Psychopathy Checklist-Revised (R. D. Hare, 1991, 2003) in which results have been largely dimensional in nature. It is concluded that scores on the PCL:SV differ quantitatively as points on a dimension (high vs. low psychopathy) rather than partitioning into qualitatively distinct categories of behavior (psychopath vs. nonpsychopath).