Research on feigned mental disorders indicates that severe psychopathology coupled with significant trauma histories often complicate feigning determinations, resulting in inaccuracies on otherwise effective measures. As part of malingering assessments, the Personality Assessment Inventory (PAI) is often used because of its excellent validation…

The challenges of accurate forensic assessment are aggravated when evaluatees have intellectual disabilities. Few studies have addressed the efficacy of forensic assessment in samples diagnosed with an intellectual disability, and those that have typically focus on measures of cognitive effort rather than on feigned psychiatric symptoms. This…

There are several important decisions that must be made when implementing taxometric procedures such as mean above minus below a cut (MAMBAC), maximum covariance (MAXCOV), and maximum eigenvalue (MAXEIG). A Monte Carlo study was performed with 10,000 (5,000 categorical, 5,000 dimensional) samples to examine 5 ways to locate the first and last…

The present study evaluated the hypothesis that autism spectrum disorders (ASDs) are best represented as a discrete category distinct from typical behavior within autism-affected families. The latent structure, categorical versus dimensional, of ASDs informs future diagnostic revisions, clinical assessment, and the design of future research. Data…

Common rates employed in classificatory testing are the true positive rate (TPR), false positive rate (FPR), positive predictive power (PPP), and negative predictive power (NPP). FPR and TPR are estimated from research samples representing populations to be distinguished by classificatory testing. PPP and NPP are used by clinicians to classify…

Determining whether individuals belong to different latent classes (taxa) or vary along one or more latent factors (dimensions) has implications for assessment. For example, no instrument can simultaneously maximize the efficiency of categorical and continuous measurement. Methods such as taxometric analysis can test the relative fit of taxonic…

There are several strategies, or models, for combining the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) validity indicators to detect malingered psychiatric symptoms. Some scholars have recommended that an elevated F (Infrequency) score should be followed by the inspection of Fp (Infrequency-Psychopathology), whereas a recent…

The Psychopathy Checklist and Psychopathy Checklist-Revised (PCL/PCL-R) were used to predict institutional aggression and community violence in two groups of forensic patients. Results showed that Facet 4 (Antisocial) of the PCL/PCL-R or one of its parcels consistently achieved incremental validity relative to the first three facets, whereas the…

The Symptom Validity Scale (Minnesota Multiphasic Personality Inventory-2-FBS [MMPI-2-FBS]) is a standard MMPI-2 validity scale measuring overstatement of somatic distress and subjective disability. Some critics assert the MMPI-2-FBS misclassifies too many medically impaired persons as malingering symptoms. This study tests the assertion of…

The purpose of this study was to determine the accuracy of "Minnesota Multiphasic Personality Inventory" 2nd edition (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) validity indicators in the detection of malingering in clinical patients with chronic pain using a hybrid clinical-known groups/simulator design. The…

Anxiety sensitivity has been implicated as a risk factor for the development and maintenance of panic and other anxiety disorders. Although researchers have generally assumed that anxiety sensitivity is a dimensional, rather than categorical, variable, recent taxometric research has raised questions concerning the accuracy of this assumption. The…

A known-groups design was used to determine the classification accuracy of Wechsler Adult Intelligence Scale-III (WAIS-III) variables in detecting malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI). TBI patients were classified into the following groups: (a) mild TBI not-MND (n = 26), (b) mild TBI MND (n = 31), and (c)…

The purpose of this study was to produce a typology of behavior problems in preschool children. Distinct subtypes were identified through the use of cluster analytic techniques on data from the Behavior Assessment System for Children (BASC)--Parent Rating Scales. Analyses were based on archival data collected on a sample of 268 children, aged 2 to…

This study examined the sensitivity and false-positive error rate of reliable digit span (RDS) and the WAIS-III Digit Span (DS) scaled score in persons alleging toxic exposure and determined whether error rates differed from published rates in traumatic brain injury (TBI) and chronic pain (CP). Data were obtained from the files of 123 persons…

A taxometric analysis of the Psychopathy Checklist-Revised (PCL-R) is conducted on a group of 409 male maximum-, medium-, and minimum-security federal prison inmates using the four PCL-R facet scores (interpersonal, affective, impulsive lifestyle, and antisocial behavior) as indicators. Results obtained from three quasi-independent taxometric…