Violent offenders more likely to perceive ambiguous faces as angry, study shows

A study conducted in Germany on male imprisoned violent offenders found no evidence that their fear processing is impaired. However, violent offenders, particularly those with pronounced aggression, were more likely to categorize certain highly ambiguous faces as angry compared to healthy controls. The research was published in Psychological Medicine.

Violent offenders are individuals who commit acts of physical aggression that cause or intend to cause harm to others, such as assault, homicide, or sexual violence. Psychologically, they tend to exhibit higher levels of impulsivity, making them more prone to act without considering consequences. Many struggle with emotional regulation, finding it difficult to manage anger, frustration, or fear. Some also display antisocial traits, including a lack of empathy, disregard for the rights of others, and manipulativeness.

Some violent offenders have histories of childhood trauma, abuse, or neglect, which can contribute to aggressive behavior later in life. Substance abuse is also common and can lower inhibitions or heighten aggression. While not all violent offenders have mental illnesses, certain disorders, such as borderline personality disorder or, in rare cases, schizophrenia, may increase the risk of violent behavior under specific conditions. Social and environmental factors—such as poverty, exposure to peer violence, or a lack of positive role models—often interact with psychological traits in the development of violent behavior.

Previous research has suggested that violent offenders may have impaired processing of fear, meaning it may be harder for them to experience fear themselves and to perceive it in others. To explore this possibility, study author Timo Stein and his colleagues conducted four experiments measuring how participants cognitively processed fearful and angry facial expressions, comparing their responses to neutral or other types of emotional expressions.

The study included 65 male imprisoned violent offenders and 60 age-matched control participants. The offenders, all convicted of violent crimes, were recruited from cooperating German correctional facilities. Among them, 21 individuals had sufficiently high scores on a psychopathy assessment to be classified as psychopathic.

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Participants completed four cognitive tasks: two visual search tasks, one ambivalence task, and one morphing task. In the visual search tasks, participants were shown arrays of eight faces—seven identical distractors and one target face. In task one, the target differed by gender and emotional expression (happy, fearful, or neutral) or was tinted red. In task two, the design was the same except that red-tinted faces were excluded.

The ambivalence task used morphs blending angry, happy, and fearful expressions at different intensities. Participants had to identify the predominant emotion by pressing the corresponding button. In the morphing task, participants viewed a gradual transition from a neutral expression to a full emotional expression (happy, angry, fearful, or sad) and pressed a button as soon as they recognized any emotional change.

Analysis of participants’ responses across tasks found no evidence that violent offenders cognitively processed fear differently than healthy individuals. Similarly, individuals with high levels of aggression or psychopathy did not show a specific bias toward perceiving angry faces more readily.

However, in the ambivalence task, which required participants to explicitly identify the perceived emotion in highly ambiguous faces (those blending 50% happy and 50% angry expressions), violent offenders were significantly more likely than controls to categorize them as angry. This tendency was particularly pronounced in violent offenders who scored higher on measures of aggression.

However, in the ambivalence task, the task that required participants to explicitly identify the emotion they perceive, and when viewing highly ambiguous pictures (50% happy, 50% angry), violent offenders were more likely than controls to categorize them as angry. This was more pronounced in violent offenders with higher aggression levels.

“In conclusion, across four experiments we found no evidence for perceptual deficits for emotion (including fear) in psychopathy, but a cognitive bias for anger linked to aggression. These results challenge the view that psychopathy arises from altered emotion processing and support the idea that a hostile attribution bias may underlie aggressive behavior,” the  study authors concluded.

The study contributes to the scientific knowledge about visual perception and processing specificities of violent offenders. However, it should be noted that the study was conducted on a very small group of violent offenders who were all male. Results on female offenders might differ.

The paper, “Perception of emotional facial expressions in aggression and psychopathy,” was authored by Timo Stein, Nina Gehrer, Aiste Jusyte, Jonathan Scheeff, and Michael Schönenberg.