The Relationship Between Psychopathy and Violence: A Comparison Across Birth Cohorts.

The current study responds to calls to consider whether individual characteristics (e.g., psychopathy) interact with broader structural conditions (e.g., economic, social, and legal contexts) in ways that influence offending. We examined whether the psychopathy-violence relationship varies across birth cohorts. Data came from 535 male and female participants from the Incarcerated Serious and Violent Young Offender Study who were interviewed in adolescence and received a rating on the Psychopathy Checklist: Youth Version (PCL:YV). Participants were born between 1979 and 1997 and were followed into adulthood to examine offending outcomes. Generalized estimating equations examined the relationship between psychopathy, birth cohort membership, and annual violent convictions between ages 18 and 40. PCL:YV scores were significantly associated with violent convictions across adulthood. Individuals from recent birth cohorts had higher probabilities of violence. Interaction analyses indicated that youth scoring high on the PCL:YV had similar probabilities of violent convictions regardless of birth cohort, whereas youth from recent cohorts who scored low on the PCL:YV had higher probabilities of violent convictions than low-scoring youth from earlier cohorts. These findings contrast with U.S. research showing that low-risk youth born in the 1980s had similar probabilities of arrest to high-risk youth born in the 1990s. This difference may reflect cross-national variation in the intensity of macro-level changes. People with elevated psychopathy traits may be more resistant to their social conditions. We discuss how changes in the composition of study populations may attenuate observed effect sizes through selection processes and recommend improving how effect sizes are contextualized.