Assessment, Ahead of Print.
Several investigators have assessed the Psychopathy Checklist–Revised (PCL-R) for invariance across offender ethnicities and in correctional and forensic–psychiatric contexts. Yet we do not know whether, or to what extent, item properties among male offenders vary throughout adulthood. With a combined sample of PCL-R data on offenders from Canada and the United States (N = 4,820), we measured item properties for offenders in age groups of Early (18-30 years old), Middle (31-49 years old), and Late (50+ years old) adulthood. Nine items showed differential item functioning across age group comparisons. Among the Early group, the PCL-R Interpersonal and Affective traits were most informative for measuring the latent trait of psychopathy. Among the Late group, the PCL-R Lifestyle and Antisocial items were most informative for the latent trait. These differences in item information illustrate how psychopathy manifests in male offenders throughout adulthood.