One out of a hundred people that you work with will be a psychopath.

At the start of my career, one of my first bosses was an out and out psychopath. A narcissistic layabout, this person's career was driven by hiving off the talent of others, taking credit for work that was not hers and bullying her staff to the point of abuse.

She was a pathological liar who was highly manipulative and destructive, and because of that she had a turnstile at the door of her department. People just didn't last long because she made working conditions absolutely intolerable.

I didn't know too much about psychology then, all I knew was that she was disturbed and dangerous. It was only later when I began to study the phenomenon of workplace bullying that I discovered she fitted the profile of a psychopath, perfectly.

I see psychopaths

Thanks to movies and televisions, when most people think of psychopaths they get a disturbing image of a serial killer with a violence-filled childhood, who remorselessly hacks people to death for fun. Shows like "Dexter" serve to fuel this image, but the truth is a lot scarier. We live and work and walk past psychopaths every day of our lives. They are our neighbours, run the lift club or can be our colleagues or our bosses.

Euphemistically termed "borderline personalities", it's a startling fact that the majority of psychopaths aren't emotionless killers, but people holding nine-to-five jobs, just like you and me. "The common misconception with psychopaths is that they're all violent extreme kind of criminals. The majority of them are living and working around us in jobs, psychologically destroying the people that they work with," says Dr John Clarke, an Australian-based psychological profiler and author of the book Working With Monsters. The book offers advice on how to identify and deal with workplace psychopaths.

Workplace psychopaths are more common than you'd think and they are individuals who charm and manipulate their way through business and life, often leaving an indelible mark on their victims. They are often extremely narcissistic, lacking in empathy, highly destructive, ruthless and can make life hell for those that work with or for them. According to Clarke, up to 3% of adult males are psychopaths, while less than 1% of women are.

How do you spot a psychopath? Well, there's the Hare Psychopathy Checklist that was developed by Dr Robert D Hare, professor emeritus of the University of British Columbia.

Hare has often called for CEO to be screened to weed out psychopaths, saying financial scandals could be prevented if CEOs were profiled to ensure they were psychologically fit to lead multimillion-dollar companies, and steer the fate of thousands of employees. Hare says the average psychopath easily moves through headhunting interviews and HR processes that don't reveal enough about candidates' psychological profiling.

The checklist was created by Hare as a diagnostic tool to rate people's psychopathic or anti-social tendencies. In short, psychopaths display anti-social behaviour that is evidenced by pathological lying, a completely lack of empathy, no sense of guilt, a lack of a conscience and very superficial emotions. Psychopaths enjoy what they do, so will have a history of victimisation and will leave a trail of destruction in their wake.

Hare's checklist:
* Glibness/superficial charm
* Grandiose sense of self-worth
* Pathological lying
* Cunning/manipulative
* Lack of remorse or guilt
* Shallow affect
* Callous/lack of empathy
* Failure to accept responsibility for own actions
* Promiscuous sexual behaviour
* Need for stimulation/proneness to boredom
* Parasitic lifestyle
* Poor behavioural control
* Lack of realistic, long-term goals
* Impulsivity
* Irresponsibility
* Juvenile delinquency
* Early behaviour problems
* Revocation of conditional release
* Many short-term marital relationships
* Criminal versatility
Obviously, the checklist isn't a tick-box for laymen diagnoses and interpretation, but is a good departure point for understanding borderline behaviour. Clarke says you can spot workplace psychopaths by looking out for the following:
* They are guiltless: Workplace psychopaths will back-stab and victimise without showing any remorse.
* They are cunning and manipulative: They can justify breaking rules and bending corporate systems to their benefit, and they prey on weakness and people's lack of self-esteem.
* They are emotionally erratic. According to Clarke, psychopaths are unable to nuance their emotions and only experience primary feelings such as happiness, sadness and anger. They shift very quickly and erratically between these feelings.
* They are charmers: They have the gift of the gab, are good orators and prefer dealing with people one-on-one than in groups.
* They are pathological liars and can often talk their way out of trouble.
* They are parasitic in that they live off others' good deeds and good work. They often take credit for innovations and ideas that are not their own.
Speaking to psychologists when writing this article, I asked whether real psychopaths could be reformed. The answer I got was that therapy simply makes psychopaths more cunning, because it gives them the tools to become better manipulators and liars, and teaches them how to fake socialisation or empathy to get what they want.

The expert's advice on what to do if you come face-to-face with a psychopath in the workplace? Quit, leave or get out the way before you get hurt.