By Prof. Corine de Ruiter

From 1995 to 2002, I worked as head of the research department in Forensic Psychiatric Center Dr. Henri van der Hoeven Kliniek in Utrecht. During these years, I interviewed many newly admitted forensic patients who had been sentenced to a TBS order by a criminal court, because they had committed a serious violent and/or sexual offense, for which they were deemed not or only partially responsible because of a mental disorder. I was intrigued by their stories of childhood adversity, including different types of child abuse and discontinuity of care, which were often supported by extensive historical file information. One group of offenders who seemed to be particularly victimized were those with psychopathy, a personality disorder characterized by impulsivity, lack of empathy, lying and deceit, and often a long and diverse criminal record. This seemed counterintuitive: why would someone who was victimized in childhood end up becoming a victimizer themselves? This excerpt from one of the biographical interviews is a telling example:

“I had a kind of rough childhood. My Mom was admitted to a psychiatric institution many times, and my Dad was extremely harsh. He and my older brothers used to hit me with a broom. They also made me sit in a corner with hot peppers in my mouth. My memories of my childhood are rather chaotic, I do not like to think about that period. I was bullied in elementary school. But then, one day, I remember I hit this kid in the school yard during recess, and that’s when I found out I could be a bully too. And from that time on, I switched from being a victim to being the perpetrator. “ (Patient A.)

Throughout the years, I tried to keep abreast of the empirical literature on childhood maltreatment and psychopathy, which seemed to show inconclusive results. In addition, over the past decades, many psychopathy researchers focused on its genetic and neurobiological underpinnings. For a critical appraisal of this literature, see the interesting publication by Frazier and colleagues (2019).

In the meantime, I kept wondering if there was a role for childhood maltreatment in the etiology of psychopathy. Back in 2018, a group of Master students in forensic psychology were interested in being involved in an extracurricular project, and I decided to start working on a meta-analysis of childhood maltreatment and psychopathy, more specifically the four facets of the disorder: Interpersonal, affective, behavioral and antisocial.

Fast forward to August 10, 2022, our meta-analysis was published in PLoSONE. Over the years, the project group stayed connected, although the students obviously graduated, got jobs and/or entered PhD programs. The COVID pandemic had a serious impact on the length of the review process: one journal we submitted to failed to assign reviewers for about 6 months, so we decided to withdraw our manuscript from that outlet in the end.

What did we find?

We found small to moderate effect sizes between psychopathy and childhood maltreatment (especially physical abuse, emotional abuse and neglect) in studies that used cross-sectional designs (mostly adults/adolescents being asked about their experiences with childhood maltreatment). Effects are stronger for the behavioral lifestyle and antisocial facets than for the affective and interpersonal facets. We also found that the associations of psychopathic traits with childhood maltreatment were largely invariant across gender, type of psychopathy measure, and publication type.

Our findings provide support for theoretical models that suggest a role for childhood trauma, and maltreatment by primary caregivers in particular, in the etiology of psychopathy. Future research needs to focus on prospective, longitudinal designs because retrospective, cross-sectional designs cannot inform us about causal directions.

If childhood maltreatment is related to the development of psychopathic traits, even to a small extent, this is obviously highly relevant information. The practical implications of our findings are that prevention of childhood maltreatment could lead to a reduction of psychopathic traits, which in turn could lead to a reduction in antisocial and violent behavior in society at large.

Want to know more?

de Ruiter, C., Burghart, M., De Silva, R., Griesbeck Garcia, S., Mian, U., Walshe, E., & Zouharova, V. (2022) A meta-analysis of childhood maltreatment in relation to psychopathic traits. PLoS ONE, 17(8), e0272704. https://doi.org/10.1371/journal.pone.0272704