Psychopaths have obvious traits that are easily identifiable such as boldness, a lack of inhibition and mean-spiritedness. Photo: Li Hao/GT

"If I kill one person, I am a killer; if I kill 10,000 people, I am a king; if I kill all the others in the world, I am God."

"Only the dead can not call the police."

The chilling words of 22-year-old university graduate Li Sida were posted on his renren.com social media homepage. As far back as 2012 and 2013, Li also wrote: "[I will] kill you" and, "Endure silently, then [I will] kill you in the darkness. Will you beg me for mercy?"

No one found these words worthy of any serious attention, until August 11, when Li killed his female classmate Zhou Yunlu in his rented home in Chaoyang district, after trying to rape her. They were in the same class for four years between 2010 and 2014.

According to the Beijing Evening News, when the police found Li, he was sleeping alone in a hotel room. He calmly told the police that the girl was already dead. When the police asked whether he had a grudge against her, or whether Zhou had done something to offend him, Li said: "No. I only wanted to kill an innocent person to give vent to my frustration."

It's only after Li killed Zhou that he was found to be mentally unstable and very dangerous. So why did Zhou and her classmates not pick this up earlier?

Experts say people with a mental disorder, medically known as psychopathy, are dangerous to both themselves and others, and have obvious traits that can be identified.

Psychiatrists say a psychopathic personality can seldom be changed, and contact with such people should be avoided as far as possible, to protect oneself. Photo: Li Hao/GT

An innate characteristic

According to Song Haidong, a psychiatrist at Beijing's No.7 People's Hospital, although some mental patients may only do dangerous things when they are having an episode, mostly, dangerous psychopaths are of quite sober mind and know what they are doing when they hurt others. In fact, they get enjoyment from inflicting pain. Song said psychopaths are able to understand and make correct judgments about the external environment.
"For example, if a man wanted to kill a woman, torture and rape her, he would be very calm about it, stalking her to get to know her time schedule, buying or making torture instruments at night, while functioning as a normal person, a perfect father and husband during the day time."

Song said certain personality disorders such as anti-social personality disorder, abusive and borderline personality disorders, sexual deviation such as necrophilia and pedophilia, and people with no mental disease other than being a little mentally imbalanced, should be treated with caution.

A common feature of dangerous people is their lack of empathy - the ability to feel and share other people's emotions, senses and thoughts. They do not care about anything other than themselves.

Some experts believe that the lack of empathy may be innate and that psychopaths are born that way.

Robert Hare, a psychologist at the University of British Columbia, conducted an experiment on psychopaths in 1991, and found that those who committed serious crimes could not distinguish between emotions.

According to the Scientific American in July 2014, the researchers recorded two groups of people's brain activity when showed the same words with different emotional tendencies. Some were positive words such as "flower," others were negative such as "scar," and some were neutral such as "door."

In normal people, their brain waves showed a crest when they associated emotions with certain words, but for the criminals, there was no difference. Their brain waves remained almost the same.

Identifying unnatural behavior

So is it possible to identify a psychopath who may harm you? Ge Shujun, a Beijing-based psychologist suggested that people can be analyzed from five aspects: social media, hobbies and interests, talking and behavior, methods and attitudes to cope with frustration and failure, and family and social relationships.

"If people had taken notice of the many times Li used the word 'kill' in his social media posts and there was a psychological intervention to help him, he might not have ended up a killer," said Ge, who thought Li's anti-social behavior was an obvious sign of his mental problems before he committed murder, and that it was a great pity that it went unnoticed.

Besides Li's posts about his desire to kill, he also had a Sina blog which is named after an old Hong Kong horror movie called The Brain (1983).

Li also posted a selfie on the Internet, in which he looked ferocious while holding a knife.

"All these self-disclosures showed that Li has a propensity for violence," said Ge by way of analysis.

"And he disregards others' lives."

"One's attitude for coping with frustration and failure usually reflects one's psychological state," said Song.

"A mentally healthy person may feel frustrated, but recovers soon, and will not deflect their hatred onto innocent people and society."

Song said a man who last week stabbed a woman to death in Sanlitun with a samurai sword, also appeared to have been unable to deal with his anger.

"I do not know what frustration he suffered, but he transferred his misfortune onto others that he did not know, which displays quite a sick mentality."

Song advised that one should not approach people carrying weapons, neither try to talk to or watch them.

Parental responsibility?

To psychologically determine whether someone has psychopathic traits, Hare created the psychological assessment, the PCL-R test, which was published in The Telegraph in April last year.

It is a list of 20 criteria and traits of a psychopath and measured either by giving the person a 0 (meaning the criteria does no apply at all), 1 (partly applies) or 2 (totally applies).

Among the traits of a psychopath are: glibness and superficial charm, a grandiose sense of self-worth, pathological lying, cunning or manipulative behavior, a lack of remorse, emotional shallowness, callousness and lack of empathy, unwillingness to accept responsibility for actions, a tendency to get bored, a parasitic lifestyle, a lack of realistic long-term goals, impulsivity, irresponsibility, a lack of behavioral control, behavioral problems in early life, juvenile delinquency, criminal versatility, a history of revocation of conditional release, multiple marriages, and promiscuous sexual behavior.

According to Hare's theory, a pure and typical psychopath would score 40. This was the score of notorious serial killer Ted Bundy, who raped and murdered more than 30 women in the US during the 1970s. A score of 30 or more also qualifies for a diagnosis of psychopathy.

According to Song, a psychopath's personality usually forms when he or she is very young, usually in childhood. In the case of adults, accidental brain trauma which changes one's brain functioning, may lead to psychopathic behavior, but mostly trauma leads to mental disorders such as anxiety, depression and acute schizophrenia rather than a personality disorder.

"So to prevent a person from becoming a psychopath, the most important responsibility lies with the parents, who have to develop a healthy concept of a family without violence and too much punishment," said Song.

"Staying mentally healthy is a life-time job. Keep happy and relaxed, and consult a professional doctor as soon as you feel something is wrong with your mind."

Both Song and Ge agreed that people should not confront people they suspect of being mentally unstable.

"When you encounter people whom you believe display the characteristics of a psychopath, the first and best way to protect yourself, is to get away from them as soon as possible," said Song. "Do not try to change or cure them. That's the responsibility of psychiatrists."