Source of article The Jury Room - Keene Trial Consulting.

The mental image many of us have of psychopaths is similar to the graphic illustrating this post. They are terrifying. “Terrifying” however is pretty vague and we need a more precise vocabulary to discuss what you see in a psychopath—that is, their core characteristics. Apparently, the more research that has been done on the psychopath, the more disagreement there is about which characteristics are “core to” or “define” the psychopath.

Here’s a study that helps to identify what the core characteristics are of the psychopath by comparing similarities and differences between psychopaths in the US and the Netherlands. In an interesting aside—the US sample is from Wisconsin. Wisconsin! Who knew there were psychopaths in Wisconsin? 

Of course, you would know if you’ve been following our various posts on psychopaths here. This sample (with 7,450 criminal offenders) is the largest we’ve seen and there are differences between Dutch and US psychopaths—which begs the question: is culture tied to how psychopathy is expressed behaviorally? The authors do raise that question and you will likely smile and roll your eyes along with us when they say the question of cultural impact on psychopathic behavior “needs more research” (we’d bet some of the authors do not yet have tenure). 

Here is what the researchers did: 

The researchers examined the scores received on the Psychopathy Checklist-Revised (PCL-R) which is the most widely used measure of psychopathy. And yes—they acknowledge that use of a single measurement could be an issue in the results reported. There is, however, an important difference between the two samples: the Dutch sample members were all “violent, mentally unwell offenders” while the US group (remember, it’s Wisconsin) were “general offenders from state prisons”. With this sample difference we’d expect to see an overall higher level of psychopathy in the Dutch sample and we do (28% in the Dutch sample compared to between 20% and 22% in the US sample). 

Here are the personality traits found to differ between the US and Dutch samples:

US: Psychopaths in this sample were most likely to show “callousness” and a “lack of empathy”. 

Netherlands: Psychopaths in this sample were also callous and lacking in empathy, but they had stronger indications of a “parasitic lifestyle”

[i.e., finding others to support them financially] and “irresponsibility”. 

The researchers completed some additional analysis but again found that a “parasitic lifestyle” and “irresponsibility” most characterized the Dutch sample while the US sample was most characterized by “callousness” and a “lack of empathy”. 

There probably are differences between psychopaths in different countries. The PCL-R is a fairly difficult measure to master since it requires two trained raters with a fairly high degree of inter-rater reliability. This study used different raters who were all “experienced” or “trained” but there is no comparison of inter-rater reliability on the reviewers completing the PCL-R across these samples. They are also comparing “violent, mentally unwell offenders” in the Netherlands with “general offenders from state prisons” and it is possible those two groups of people are just different from each other.

Attorneys (along with the rest of us) may find themselves having to work with—or for—someone who qualifies as a psychopath. If you are representing a psychopath (whether criminal or civil) we would suggest you (at minimum) read our blog posts on psychopaths, get paid up front, and do not respond to that well-known yet superficial charm so typical of many psychopaths who never reside in prison. 

Verschuere, B., van Ghesel Grothe, S., Waldorp, L., Watts, A. L., Lilienfeld, S. O., Edens, J. F., Noordhof, A. (2018). What features of psychopathy might be central? A network analysis of the Psychopathy Checklist-Revised (PCL-R) in three large samples. Journal of Abnormal Psychology, 127(1), 51-65.