The Psychopath's Brain

Renato M.E. Sabbatini, PhD


Tormented Souls, Diseased Brains

Emotionally Insensitive

Psychopathic Serial Killers

To Know More

The Author


As Dr. Robert Hare, the noted Canadian researcher on the phychopathic personality, has pointed out in his book, most persons are unable to understand how a criminal and antisocial personality such as that of serial killers, is possible in a human being like ourselves.

Not only serial and mass killers, but a large proportion of violent criminals in our society (as much as 25 % of the inmate population) show many of the characteristics of what psychiatry has named  "sociopathy", or more properly, "antisocial personality disorder" (APD), a better and more precise term than psychopathy. DSM-IV, the important diagnostic manual used by psychologists and psychiatrists, defines APD as a disorder entity and lists its main characteristics, which can be easily recognized in affected individuals. The World Health Organization has also defined sociopathy in its classification of diseases, ICD-10, using the term "dissocial personality disorder".

Sociopaths are characterized by a disregard for social obligation and a lack of concern for the feelings of others. They display pathological egocentricity, shallow emotions, lack of insight, poor control of impulsiveness (including a low tolerance for frustration and a low threshold for discharge of aggression), irresponsibility, a lack of empathy for other human beings and of remorse, anxiety or guilt in relation to his/her antisocial behavior. They are usually callous, manipulative individuals, incapable of lasting friendship and of love. They shamelessly lie, cheat, steal, abuse, neglect their relatives and families, and endanger themselves and other people in a reckless manner. Hare characterizes them as "intraspecies predators who use charm, manipulation, intimidation, and violence to control others and to satisfy their own selfish needs. Lacking in conscience and in feelings for others, they cold-bloodedly take what they want and do as they please, violating social norms and expectations without the slightest sense of guilt or regret."

Sociopaths are unable to learn with punishment, and modifying their behavior. When they discover that their behavior is not tolerable by society, the react by hiding it, never by suppressing it, and by cunningly disguising their personality traits. Thus, in the past psychiatrists have used the term  "moral insanity" or "insanité sans délire" to characterize this psychopathology. The classical sociopath has been Donatien-Alphonse-François de Sade (1740-1814), a French nobleman whose perverse sexual preferences and novels (such as Justine) originated the term sadism.

The sociopathic individual usually displays a superficial charm to other people and has a normal or above normal intelligence, and does not show symptoms of other mental diseases, such as neuroses, hallucinations, delusions, irrational thinking or psychoses. They may have a serene countenance on normal social intercourse, and have a considerable social presence and good verbal fluency. In some cases, they are leaders in their social groups. Very few persons, even after lenghty contact with sociopaths, are able to imagine their  "black side", which most of the sociopaths are able to hide succesfully during their whole life, leading a double existence. Fatal victims of sociopathic killers perceive their true side only moments before their death.

Most scaring is the fact that between 1 and 4 % of the population is sociopathic in a lesser or larger degree. Of course, most of the persons with SPD are not criminals and are able to control it within the limits of social tolerability. They are considered only  "socially obnoxious" or hateful personalities, and every one of us knows of someone who fits the description. Corrupt and callous politicians, social or career fast climbers, authoritarian leaders, abusing and aggressive persons, etc., are among them. A common characteristic is that they engage systematically in deception and manipulation of others for personal gain. In fact, many successful and adapted non-violent sociopaths can be found in our society. An NIMH epidemiologic study reported that only 47% of those who met the SPD criteria had a significant arrest record. The most relevant events for these persons occur in the area of job problems, domestic violence, traffic offenses, and severe marital difficulties. Many people avoid individuals with this personality disorder because they are irritable, argumentative, contentious and intimidating. Their behavior is oftentimes brash, unpredictable and arrogant.

Sociopathy is recognized early in an individual: it begins in childhood or early adolescence and continues into adulthood (the diagnosis is possible around 15-16 years old). Sociopathic children manifest tendencies and behaviors which are highly indicative of their disorder. For exemple, they are seemingly immune to parental punishment, and are not affected by pain. Nothing works to alter their undesirable behavior, consequently parents usually give up, which makes the situation worst. Violent sociopaths show a history of torturing small animals when they were children, firesetting and vandalism, systematic lies (truancy), stealing, aggression to school mates and challenge to the authority of parents and teachers.

However, a tiny fraction of sociopaths develops into violent criminals, rapists and/or recidivist killers. In more severe cases, the disease can evolve into cannibalistic and sadistic rituals of torture and death, often of a bizarre nature. The is widespread consensus that these extreme forms of violent sociopathy are untreatable and that their bearers must be confined for life in special asylums for the criminal insane. A typical sociopath of this kind has been portrayed by Dr. Hannibal "The Cannibal" Lecter in the  "The Silence of the Lambs" book and film. Or, they are executed, in countries or states where the death penalty is adopted.

Violent sociopaths describe themselves as  "predators" and are usually proud of it. They lack the usual type of aggressive behavior, which is violence accompanied by an emotional discharge (usually anger or fear) and an arousal of the sympathetic nervous system (pupil dilation, increased heart rate and respiration, adrenaline discharge, etc.). Their kind of violence is similar to predatory aggression, that is accompanied by minimal or no sympathetic arousal and is planned, purposeful, and without emotion ( "cold-bloodness"). This is correlated with a sense of superiority, so that they like to exert power and unrestricted dominance over others, ignoring their needs and justifying the use of whatever they feel compelling to achieve their goals and avoid adverse consequences for their acts. For example, in Justine, the character who embodies the Marquis de Sade says that everything is justified when it comes to the gratification of his senses, and that he is allowed to use other human beings as he wishes for that purpose. The fact that sociopaths have little empathy for the suffering of others has been experimentally demonstrated in many studies which have shown that they display abnormal processing of the emotional aspects of language, and that they have unusually weak physiological responses (in the autonomous nervous system) to images, words and situations of high emotional content. As it happens with predators, sociopaths are able of extremely heightened attention in certain situations.

The sociopathic disorder is also highly associated with the incidence of drug abuse and alcoholism. In fact, this association makes worse many aspects of sociopathic behavior, thus they are mutually reinforcing.

ASD is relatively easy to diagnose. The same Dr. Hare has developed an assesment scale, called the Psychopathy Checklist-Revised (PCL-R), which is useful for this purpose, particularly when evaluating criminals (the forensic population). You may test yourself using an on-line scale available at Internet Mental Health.

Violent sociopaths exact a high toll onto human society. In the USA, more than half of the police officers killed by criminals were victims of sociopaths. ASP is common among drug offenders, women and child abusers, gangsters, terrorists, sadists, torturers, etc. In addition, "psychopaths are approximately three times more likely to recidivate--or four times more likely to violently recidivate--than were non-psychopaths", according to a recent study. Citing again Dr Robert Hare: "The enormous social, economic, and personal suffering inflicted by a few people whose antisocial attitudes and behavior result less from social forces than from an inherent sense of entitlement and an incapacity for emotional connection to the rest of humanity. For these individuals - psychopaths - social rules have no constraining force, and the idea of a common good is merely a puzzling and inconvenient abstraction."

Furthermore, under stressing social situations such as in wars, general poverty and breakdown of the economy, sweeping epidemics or political fighting, etc., sociopaths may acquire the status of regional or national leaders and saviors, such as Adolf Hitler, Stalin, Saddam Hussein, Idi Amin, etc. When they are in positions of power, they can inflict far more damage than as individuals.

What is the cause of sociopathy ? How the brain is involved ? How it can be prevented and treated ?

These are important questions for humankind, for law, enforcement and medicine. The ascending curve of senseless violence, often by young people (as time passes, younger and younger...), imposes a sense of urgency in obtaining answers to them.

In this paper, we will explore what neuroscience currently knows about this baffling disorder.

Tormented Souls, Diseased Brains

The Author

Renato M.E. Sabbatini is a neuroscientist with a PhD in neurophysiology of behavior by the University of São Paulo, Brasil, and a post-doctoral fellow in the Department of Behavioral Physiology of the Max-Planck Institute of Psychiatry, Munich, Germany. Currently, Dr. Sabbatini is the director of the Center for Biomedical Informatics and Chairman of Medical Informatics of the Medical School of the State University of Campinas, Campinas, Brazil. He is also the associate editor of  "Brain & Mind" magazine, and editor-in-chief of Informática Médica and Intermedic, a journal on Internet and Medicine.