Psychopaths aren't just crazed killers in the movies. They are among us - and not very easy to spot.
Psychopaths - it's not just dictators and movie maniacs
Do psychopaths run the world? The answer might seem obvious. But not quite in the way you'd expect.
"Psychopath" is often bandied about as an insult against those we perceive through the prism of news, popular culture, or personal experience. Charles Manson. The axe-wielding Jack Torrance in The Shining. Your Facebook stalker.
The reality is far more complex.
Outwardly, psychopaths appear normal. However, they feel no shame, guilt, or remorse, and gain satisfaction out of antisocial or violent behaviour. Above all they share a distinct lack of empathy for others, and are unable to foster genuine human attachment. In the 1880s the French psychologist Philippe Pinel coined the term manie sans delire ("mania without delirium") for them. They are not easy to spot.
In his recently published book The Psychopath Test: A Journey Through The Madness Industry, Jon Ronson raises, like many other psychiatrists before him, this question: do psychopaths rule the world? The author set out to investigate "this brain anomaly that leads some people to become killers [and] leads other people to become ruthless, vicious CEOs" and why "capitalism is a physical manifestation of psychopathy."
Central to psycho-spotting is the titular test, a series of 20 questions devised by Dr Robert Hare that outline the traits shown by sufferers. Each is marked with a 0,1 or 2. Score 30 or over, and you're a psychopath.
The items on the list are revealing, if only in how they relate to figures recently in the news.
Grandiose sense of self-worth (Anders Behring Breivik); callous/lack of empathy (Col Muammar Qaddafi); failure to accept responsibility for own actions (Hosni Mubarak); and criminal versatility (Osama bin Laden) are just a few of those categories.
But what of psychopaths whose vocation is not to kill and maim? Where do the undetectable ones dwell? The answer is, all around us.
Psychopathy afflicts almost 1 per cent of us. If you have 500 friends on Facebook, five are psychopaths.
And since, with a few exceptions, we avoid intentionally befriending mass murders and maniacal dictators, that means a percentage of our friends, colleagues and people we encounter on a daily basis - say, on our roads - are psychopaths.
Armed with Hare's checklist, spotting them might be easier. Alternatively, there is a danger in seeing psychopathy in the most mundane of actions. Sometimes, she's simply just not into you.
"I was attaining a new power, like a secret weapon," Ronson said in his book. "I was contemptuous of those naive people who allowed themselves to be taken in by slick-tongued psychopaths."
So, that creepy roommate? Potentially a psycho. The horrible boss? Psycho. A hit-and-run perpetrator? Definitely a psycho.
But are psychopaths self-aware, or do they live their lives blissfully unaware of the damage they inflict? Do dictators sleep well at night?
In Joseph Heller's bureaucracy-critiquing book Catch-22 - which gave its name to the widely used phrase - his fictional World War II US airmen could avoid flying dangerous, almost suicidal, missions only if they were clinically insane. The "catch" is, anyone who is fully aware of the risks and requests to be grounded is automatically deemed of sound mind, and therefore has no option but to fly.
By the same logic, does the mere act of acknowledging you are a psychopath, and hence able to control your actions, mean that you are no longer one? Opinion is split.
Psychopathy, as things stand, has no cure: empathy cannot simply be instilled into a person, nor can an individual be made to feel love. Today, there is no consensus among psychiatrists and physicians on its diagnosis, and many believe that even the term psychopath is inappropriate, as most people exhibit at least a few of the traits on Hare's list.
Hurtful words, after all, are not the same as killing someone softly, whatever Roberta Flack says.