How to recognize a psychopath? Just check the movement of the head

A team of psychologists from the University of New Mexico used artificial intelligence to identify psychopaths. The experiment was conducted on prisoners, but its results may prove useful in studying various groups. Especially since the experts noticed that the movements of the psychopaths' heads gave them away.

A team of scientists from the University of New Mexico, led by Prof. Kent Kiehl, has developed a tool that may prove extremely useful in identifying psychopaths. It is based on artificial intelligence and machine learning. The tool identifies behaviors that are typical for psychopaths.

During the experiments that were described in the "Journal of Research in Personality", experts, using a special machine learning program, monitored the behaviors of 507 inmates (these were adult men) during interviews with them. They noticed that prisoners who exhibit more features associated with psychopathic personalities keep their heads still.

Each interview lasted from one to four hours, and a head motion tracking algorithm processed at least 36,000 frames of footage for each of the inmates. It focused on six reference points on the face. To detect psychopathic tendencies, scientists also used the "Hare Psychopathy Checklist-Revised" checklist, a test taking into account qualities such as interpersonal, emotional, or life-style related characteristics.

The aforementioned test assesses a total of 20 criteria, and the score one can receive ranges from 1 to 40, with 25 indicating that the person has a high level of psychopathic traits (in the USA, this threshold has been set at 30 points).

The study showed that people with more psychopathic traits make fewer head movements. Their head is more stable. In addition, such a person directs their head directly at the camera or the person conducting the interview. Scientists are not entirely sure why this happens. However, they have several theories on this matter. One of them refers to the way the amygdala, or the area of the brain involved in processing emotions, functions in psychopaths.

"Nonverbal behavioral signals associated with psychopathy may partly reflect the neurobiological basis of the disease, and partly result from deliberate and strenuous interpersonal manipulations," as can be read in the "Journal of Research in Personality". Scientists also note that dysfunction of the amygdala is a characteristic neurobiological feature of psychopathy, affecting emotion processing, learning process, or personal interactions.

Experts emphasize that their tool has certain limitations. Firstly, the software was not tested on women, and also on teenagers. The study involved only adult men. Additionally, the algorithm does not monitor eye movements, which is also important. Therefore, scientists plan to continue the research and expand the algorithm with additional capabilities, including the observation of non-verbal, subconscious behaviors such as hand movements or the way a person speaks. This will allow for even more accurate identification of psychopaths.