Are Murderers Unfairly Labeled Psychopaths?

There is a robust link between murder and psychopathy.

Posted Dec 17, 2018

Psychopaths as a group are an intriguing if disturbing lot. As I noted in a previous post, there is considerable debate about what psychopaths are really like. Psychopathy has classically been considered the darkest and most malevolent of psychological conditions, yet some people argue that there is a positive side to psychopaths as well (see these two posts for further discussion). In fact, there are even some people arguing that psychopaths are unfairly stigmatized and misunderstood because of negative portrayals in the media (Durand, Plata, & Arbone, 2017).

Specifically, these authors state: “Psychopaths are continually presented as criminals and feared due to their supposed aggressive tendencies, stemming from the excessive labelling of murderers as psychopaths by the media and popular culture.” Note the use of “supposed” aggressive tendencies, and “excessive” labelling. On the contrary, these authors state, “a growing body of evidence suggests that psychopathy is not strongly linked to increased violence and criminal behavior.” They argued that stigmatization of psychopaths is a problem because people labelled as such are denied full social acceptance, and may be disadvantaged in many areas of life, such as being denied employment opportunities and having an impoverished social life.

However, as I showed in my previous article, media portrayals of psychopaths are not always entirely negative, and sometimes present psychopaths as possessing admirable qualities, such as high intelligence and bravery (Keesler & DeMatteo, 2017), even though these are not core characteristics of psychopaths. On the other hand, research has shown that people diagnosed as psychopaths do have higher rates of violence than other people, and that psychopathic criminals are more likely to re-offend than non-psychopathic criminals. What I specifically want to focus on in this article is the issue of the allegedly “excessive labeling of murderers as psychopaths” and what degree of truth this might have.

Wikimedia Commons
Gilles de Rais, history's first known serial killer, and possible psychopath
Source: Wikimedia Commons

Before addressing this, I need to briefly discuss what psychopathy is and how it is assessed. Although there is debate about what characteristics best define what makes someone a “psychopath,” there is general agreement that the core features include lack of empathy, callous-manipulative traits, irresponsibility, and willingness to violate other people’s rights. There is also debate about whether psychopathy should be considered a distinct category, in which case one could say that a person is or is not a “psychopath,”  or whether it is better to consider psychopathy as something that falls along a spectrum of traits, so that one could say a person is more or less psychopathic to some degree. The most widely used tool to assess psychopathy in forensic settings is Robert Hare’s Psychopathy Checklist–Revised (PCL-R), in which a trained interviewer will rate a person on 20 different traits and assign them a score from 0 to 2 for each one, so that the total score can range from 0 to 40. A person may be diagnosed as a psychopath if they score above a predetermined cut-off. In North American settings, this is typically 30, but in other countries, such as the UK and Europe, a cut-off score of 25 is more commonly used. Hence, using the PCL-R score, one can talk about psychopathy using either a categorical approach (i.e., use the cut-off score to make an either/or decision) or a continuous approach (i.e., consider the total score regardless of whether it meets a cut-off).

Using the cut-off can be convenient in some respects, as one can then estimate the percentage of psychopaths in the general population. For example, using a conservative cut-off of 30, it has been estimated that about 1 percent of the general population would qualify as psychopaths (Fox & DeLisi, 2018). On the other hand, using the continuous approach is less arbitrary and allows relative comparisons, so that someone might be low, medium, or high on psychopathic traits. For example, some experts consider someone scoring between 20 and 25 to be “moderately” psychopathic, even though they are below the typical cut-off (Fox & DeLisi, 2018).

To help determine to what extent murderers tend to be psychopaths, a recent paper performed a meta-analysis of 22 studies of more than 2,600 homicide offenders in six countries, in which each offender’s psychopathy score was assessed using either the PCL-R or PCL-YV (youth version, used for juvenile offenders) (Fox & DeLisi, 2018). They found that the average PCL-R score for someone who had committed murder in these studies was 21.1, with scores ranging from 9.4—31.5. Robert Hare estimated that the average PCL-R score in the general non-offender population is 4 or 5, so this means that all the offenders were at least somewhat higher than the community average and that most murderers studied could be considered at least “moderately” psychopathic.

They also compared murderers based on whether they met particular psychopathy cut-off scores, and found that using a cut-off of 25, 34.4 percent would be diagnosed as psychopaths, while using a more conservative cut-off of 30, 27.8 percent would meet this diagnosis. Hence, depending on the criterion used, one could say that between about a quarter to just over a third of convicted murderers could be considered psychopaths.

To put this in perspective, remember that it has been estimated that about 1% or so of people in the general community could be considered psychopaths. Additionally, the study found that more violent and extreme forms of homicide were even more strongly associated with psychopathy scores. Specifically, those who committed murders involving sexual and/or sadistic elements had higher average psychopathy scores compared to those who committed less heinous forms of murder.

The authors concluded that there is a strong link between psychopathy and homicide, and that psychopathic traits are “a significant risk factor for lethal violence.” Furthermore, “as the homicide type became more violent, extreme, or horrific, the relationship between psychopathy and the homicide sub-type became stronger.” Hence, while not all murderers are psychopaths and not all psychopaths are murderers, psychopaths commit a disproportionate number of murders. Furthermore, murderers generally seem to have unusually high levels of psychopathic traits compared to most people. It seems fair to say that psychopathic traits, such as callousness, coldness, recklessness, and criminal lifestyle facilitate the commission of the most horrific crimes. Lack of empathy, in particular, seems to be a very important factor in a person’s willingness to inflict unnecessary suffering on a victim, such as in sadistic murders.

Returning to claims by Durand and colleagues that psychopaths are unfairly stigmatized, one of their arguments was that the media and popular culture identify murderers as psychopaths to an “excessive” degree. What is considered “excessive” is somewhat subjective, but considering that between a quarter and a third of murderers appear to be clinical psychopaths, despite the latter making up about 1% of the population, it does not seem too much of a stretch to say that murderers tend to be psychopathic.

Regarding stigma more generally, it seems worth pointing out that most other psychological conditions, and personality disorders in particular, do not seem to have this specific association with violence, let alone murder, that psychopathy (and the closely related antisocial personality disorder) have. This would be because these other disorders do not include lack of empathy and interpersonal antagonism as core features, which is specific to psychopathy. For example, a wide range of psychological problems are linked with high neuroticism, but this trait is not particularly associated with antagonism to others, but with high emotional distress instead. Hence, while it seems generally unfair to socially exclude and stigmatize people for having mental disorders, I think that psychopathy, being a special case, might be considered an exception.

© Scott McGreal. Please do not reproduce without permission. Brief excerpts may be quoted as long as a link to the original article is provided. 


Durand, G., Plata, E. M., & Arbone, I.-S. (2017). Negative attitudes towards psychopaths: The role of one’s own psychopathic traits. Personality and Individual Differences, 109, 72–76.

Fox, B., & DeLisi, M. (2018). Psychopathic killers: A meta-analytic review of the psychopathy-homicide nexus. Aggression and Violent Behavior.

Keesler, M. E., & DeMatteo, D. (2017). How Media Exposure Relates to Laypersons’ Understanding of Psychopathy. Journal of Forensic Sciences, 62(6), 1522–1533.