As a psychoanalyst, Stone's specialty is personality disorders so it is not surprising that most of the mass murderers in his study were diagnosed with antisocial, psychopathic, narcissistic or paranoid personality disorder.
Schizophrenia and Antisocial Personality Disorder are the most common diagnoses amongst serial killers. While some people, like Son of Sam, Cosmo DiNardo, and Ted Bundy act upon their disorders, there are an abundance of people in the world who have these illnesses and do not do anything with regards to harming others.
As a group, serial killers suffer from a variety of personality disorders, including psychopathy, anti-social personality, and others. Most, however, are not adjudicated as insane under the law.
The symptoms appear because they have a mental health concern and we call it antisocial personality disorder. Reports say Ted Bundy, who confessed to 30 killings had antisocial personality disorder. John Wayne Gacy with 33 victims and Charles Manson, the leader of Manson Family Cult also had APD.
US and international to date research suggests that individuals with schizophrenia and bipolar disorder are responsible for approximately 10% of all homicides in the United States. For mass killings, the percentage is approximately 33% (see “Serious Mental Illness and Mass Homicide”).
Some of the most well known serial killers have been diagnosed with narcissism; Ted Bundy and Jeffery Dahmer are both known to have NPD.
They also compared murderers based on whether they met particular psychopathy cut-off scores, and found that using a cut-off of 25, 34.4 percent would be diagnosed as psychopaths, while using a more conservative cut-off of 30, 27.8 percent would meet this diagnosis.
They found it in Monoamine Oxidase A (MAOA), which has been credited with being the “most common denominator” amongst serial killers.
Scientists searched and found what is believed to be hard evidence, that genetics is the key role in determining who becomes a serial killer unlike criminologists and psychologists who argue that large events such as abuse and abandonment create the setting and foundation in which serial killers grow into sadistic mass ...
Numbers peaked in the 1970s when there were nearly 300 known active serial killers in the U.S. In the 1980s, there were more than 250 active killers who accounted for between 120 and 180 deaths per year. By the time the 2010s rolled around there were fewer than 50 known active killers.
After studying cases and analyzing factors, it is concluded that multidimensional factors such as hormones, brain damage, and genes lead to the possibility of a person's biological crime, and social structure, education, and other aspects determine whether a person will commit a crime.
They also included a range of measures of intelligence. Overall, the team found no evidence that psychopaths were more intelligent than people who don't have psychopathic traits. In fact, the relationship went the other way. The psychopaths, on average, scored significantly lower on intelligence tests.
There is evidence that crimes committed by antisocial versus borderline personality disordered individuals differ. A study on personality clusters showed subjects with antisocial and borderline personality disorders are most commonly related with criminal behavior.
When psychopaths cry, Glass says they will often wipe underneath each eye, one at a time. "When people cry genuine tears they cry with both eyes, and so they will tend to wipe both eyes at once."
Although both biological and environmental factors play a role in the development of psychopathy and sociopathy, it is generally agreed that psychopathy is chiefly a genetic or inherited condition, notably related to the underdevelopment of parts of the brain responsible for emotional regulation and impulse control.
Like healthy people, many psychopaths love their parents, spouse, children, and pets in their own way, but they have difficulty in loving and trusting the rest of the world.
Sociopaths don't have feelings or emotions, nor do sociopaths cry genuinely. However, they do experience proto-emotions, primitive emotions that rear their ugly heads in moments of perceived need. The sociopath is quite capable of intense anger, frustration, and rage.
According to Perpetua Neo, a psychologist and therapist who specializes in people with DTP traits, the answer is no. "Narcissists, psychopaths, and sociopaths do not have a sense of empathy," she told Business Insider. "They do not and will not develop a sense of empathy, so they can never really love anyone."
1. Ted Bundy. Perhaps one of the most prolific and famous sociopaths and psychopath figures in modern history.
This study revealed that Blood group O was most frequent among the ABO blood groups occurring with highest frequency in most of the crimes recorded in this study.
"Many experts agree that serial killers have a vision in mind of their victim. This person would be thought of as their “ideal victim” based on race, gender, physical characteristics, or some other specific quality.
In a normal person, the left side of the brain has more activity than the right- side. The brain of a serial killer also has lack of activity in the prefrontal cortex that is responsible for personality and cognitive behaviors. Serial killers go through a different thought process than the average person.