New research casts doubt on the conventional wisdom linking psychopathy to murder. The findings, which appear in the scientific journal Personality and Individual Differences, provide evidence that homicide offenders tend to be less psychopathic on average compared to other criminal offenders.
“Exploring personality traits in criminal offenders is important for several reasons: these data can help investigative authorities to find the perpetrator, findings can elevate the success rate of psychological treatment of offenders and even facilitate prevention of criminal behavior,” explained study author Janko Međedović, a senior scientific associate at the Institute of Criminological and Sociological Research in Belgrade.
“The best candidates for explaining criminal behavior are the ‘dark’ personality traits: psychopathy, Machiavellianism, narcissism and sadism. Previous research showed that psychopathy is associated to the homicide offence; furthermore, the obtained associations were high in magnitude – this suggest that murderers are highly likely to have psychopathic traits.”
“We were intrigued by this finding, mostly because murder can be very heterogenous regarding the context of the offense and the motivation of perpetrator,” Međedović explained. “For example, an individual that murders a spouse and doesn’t have any previous history of criminal behavior, and a person who commits murder as a member of organized criminal group may have quite different personality profiles.”
For their new study, the researchers measured psychopathy, Machiavellianism, and sadism in a group of male convicts. The study examined 247 convicts from two of the largest penitentiary facilities in Serbia. The sample included 46 homicide offenders, 82 non-homicide violent offenders, and 119 non-violent offenders.
Criminal recidivism, including the number of criminal offences, the number of legal sentences, and the number of prison sentences served, was also assessed using the convicts’ prison dossiers.
“We found that the dark traits were positively associated with criminal recidivism (similarly to previous studies), but the homicide offenders had lower levels of psychopathy and sadism compared to other groups of offenders, especially to the non-homicide violent offenders,” Međedović told PsyPost.
“We believe that this can be partially explained by the fact that homicide offenders from our sample also had lower recidivism rates compared to other groups. Therefore, murderers may not be characterized by highly pronounced dark traits – homicide offences are heterogeneous in many criminologically-relevant aspects and the personality traits of homicide offenders can be different as well.”
“Thus, we need to explore personality dispositions of homicide offenders in more detail, by analyzing the characteristics of the offence as well,” Međedović said. “For example, it is probable, as found in previous studies, that murderers who were not close to their victims and who committed more premeditated and planned acts of murder may indeed be characterized by higher levels of psychopathic traits.”
The findings are in line with at least one other study, which examined 478 convicts from three prisons in the state of Pennsylvania. That study, published in 2017, found that homicide offenders tended to have lower levels of psychopathy compared to recidivistic offenders and similar levels of psychopathy compared to first-time offenders.
But as with any research, the new study includes some caveats.
“Our study has several limitations. For example, we did not have additional information about the characteristics of homicide offenses in our data; this is partially due to relatively low sample size of the participants who commit murder in our research,” Međedović explained. “Secondly, we used self-report inventories to measure the dark traits; it would be highly beneficial to combine these measures with the rating assessments (provided by skilled professionals) to analyze the data (rating measures exist only for psychopathy so far) because these two methods may provide different findings.”
“Various socio-economic conditions and their interactions with personality traits should be studied as well in order to provide a more detailed understanding of criminal behavior,” Međedović said. “So far, our research contributes to the psychology of criminal behavior by showing that the dark personality traits can advance our knowledge about the stability of criminal behavior and the type of criminal offence; hence, future studies can benefit by including them in the research designs.”
The study, “How dark is the personality of murderers? Psychopathy, Machiavellianism, and sadism in homicide offenders“, was authored by Janko Međedović and Nikola Vujičić.
