The science of psychopathy is a field which has captured the public’s imagination for decades- whether accurate or not, the idea that somebody we know, or a stranger on the street could secretly be incapable of feeling guilt, remorse or positive emotions is a topic which has inspired countless works of fiction and documentaries.
The NIH Medical Institute defines psychopathy as: “A personality disorder characterised by deficits in personality and behaviour. Personality deficits are marked by interpersonal and affective facets, including pathological lying, grandiose sense of self-worth, lack of remorse and callousness. Behavioural deficits are defined by lifestyle and antisocial deficits, including impulsivity, parasitic lifestyle and poor behavioural controls.”
Is it possible to spot a psychopath on the street? Part of the fixation on this condition is that those afflicted with it are indistinguishable from everyday members of the public, playing into well-worn tropes of ‘the enemy within'. But studies have shown that while an official diagnosis would be next to impossible in this context, psychopaths do indeed exhibit some tell-tale behaviours during nonverbal communication.
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Chief amongst these signs is the classic ‘psychopathic stare’. Described by Dr. Robert Hare as involving 'intense eye contact and piercing eyes', studies have shown that psychopaths’ pupils do not dilate when viewing scary or graphic images and that they tend to hold gazes for an uncomfortably long time - especially when engaging in deception or persuasion.
Now another study into the psychopathic stare by the Journal of Research in Personality offers new insights into this phenomenon.
After using an AI to analyse interviews with over 500 inmates at a New Mexico prison, researchers found that inmates who scored high in psychopathic traits tended not to move their heads much when they speak.
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“Nonverbal behavioural cues are a significant part of an individuals’ communication style and often enhance the understanding of verbal content,” researchers stated in their report.
“There have been several studies examining the relationship between nonverbal behaviours and psychopathy. Evidence suggests high trait levels of interpersonal manipulation in psychopathy is associated with less detectable emotional facial expression during deceptive communication, suggesting either effortful control of or relative dampening of typical non-verbal cues of emotion.”
So why study head movements at all? Researchers had previously noted that nonverbal behaviours play a crucial role in communication, and that prior research into interpersonal communication has found that head movement and direction can help convey emotions such as agreement, dissent, and confusion.
By combining this knowledge with prior research into the psychopathic gaze, researchers noted, the unique ways that psychopaths communicate nonverbally could offer clues into the neurological underpinnings of the condition and help improve how clinicians identify psychopaths.
Tom Sanders