Psychopathic Traits Differ Depending on Which Family Member Is Killed, Study Finds

New research has found that emotional coldness and lack of remorse are key traits separating different types of family homicide, with parental and child killings showing the deepest emotional deficits. The study, published in the journal Deviant Behavior, offers a rare comparative look at psychological patterns across family murder subtypes.

The article, titled “The Role of Psychopathic Traits in Subtypes of Family Homicide,” was authored by Jiseun Sohn, Adrian Raine, and Young-Oh Hong and appears in the journal Deviant Behavior.

Family homicide is a persistent yet understudied form of lethal violence. While previous work has linked psychopathy to homicide in general, few studies have examined how specific psychopathic traits vary between those who kill partners, parents, children, or siblings. The new analysis aims to clarify these internal differences.

How the study was conducted

The research team, led by Jiseun Sohn of Southern University and A&M College, drew on data from 213 individuals convicted of family homicide in South Korea between 2016 and 2018. All had undergone detailed psychological assessment during prison intake interviews.

Offenders were grouped into four categories: 143 intimate partner homicide cases, 35 parricides involving parents or older relatives, 22 filicides involving children or younger descendants, and 13 siblicides involving siblings. These groups were then evaluated using the Psychopathy Checklist-Revised.

This widely used tool breaks psychopathy into four facets: interpersonal problems, affective deficits, an unstable lifestyle, and antisocial behavior. Each offender received scores across these dimensions based on interview data and official records, allowing researchers to compare psychological profiles between homicide types.

Affective deficits emerge as key factor

The most striking finding was that affective deficits, such as lack of empathy, guilt, or emotional depth, showed the clearest differences among offender groups. Parricide offenders displayed the highest scores on this facet, indicating particularly pronounced emotional detachment.

Individuals who killed parents, children, or partners all scored higher on affective deficits than those who killed siblings. By contrast, siblicide offenders showed the lowest overall psychopathy scores across all four facets, suggesting their crimes may be more situational than rooted in severe personality disorders.

The researchers argue that siblicide may more often stem from acute conflicts, such as financial disputes or long-running rivalries, that escalate into lethal violence. In these cases, intense anger and opportunistic aggression may matter more than deep-seated psychopathic traits.

Differences across family roles

Filicide offenders also showed elevated affective deficits, aligning with broader psychiatric literature that links some child killings to severe mental illness and extreme emotional disturbance. The study suggests that when empathy is profoundly impaired, children within the family can become especially vulnerable.

Intimate partner homicide offenders differed in a distinct way, scoring higher on interpersonal problems and antisocial behavior than those who killed parents. These traits include manipulativeness, pathological lying, and a longer history of rule-breaking or aggression.

According to the authors, this pattern reflects a tendency among some partner killers to view relationships as tools for control or personal gain. When that perceived control is threatened, longstanding antisocial tendencies can erupt into lethal violence against a spouse or romantic partner.

Implications and limitations

The study found that psychopathic traits did more to distinguish homicide subtypes than demographic factors such as age, gender, education, or income. This suggests that psychological assessment could provide valuable insight for risk evaluation in high-conflict families.

Forensic professionals might use detailed personality profiles to identify households where extreme emotional detachment is present, especially in parent–child relationships. Targeted interventions could then be designed to address specific relational and emotional risks before conflicts escalate.

However, the authors caution that their findings are exploratory. The data were collected retrospectively, after the murders were committed, which may influence how offenders present themselves during assessment. The study also lacks a comparison group of non-lethal violent offenders.

In addition, some homicide categories, particularly siblicide and filicide, were based on relatively small samples. The researchers note that larger, cross-cultural studies are needed to confirm whether similar patterns hold in other countries and legal systems.

Despite these caveats, the study provides one of the clearest portraits to date of how specific psychopathic traits map onto different forms of family homicide. By moving beyond broad labels and focusing on detailed emotional and interpersonal characteristics, it opens new avenues for understanding and possibly preventing the most extreme forms of domestic violence.

Article prepared by Alex Morgan.