By LOUISE CARR, Associate Editor and Featured Columnist
Do you know someone who's overly confident, selfish, insincere and prone to violent outbursts that they later take no responsibility for? If so you could be married to, best friends with, or related to a psychopath.
With around 1 to 5 percent of the world's population classified as psychopaths and the population of the United States standing at nearly 314 million, that's 3.14 million psychopaths living in the US today.
Why the huge number? Are there risk factors for psychopathy as there are for diabetes, or heart disease? Do all psychopaths kill or use violence? Should you be afraid - and could you even be a psychopath yourself?
What is a Psychopath?
The term "psychopathy" is a combination of the Greek words "psyche" (meaning soul) and pathos (meaning suffering).
The term "psychopath" was first used in the 1800,s after a group of doctors noted that certain patients in mental institutions suffered from what they called a "moral depravity" or "moral insanity" - these people seemed not to possess any sense of responsibility to other people or any ethics.
Scientists later changed the term to "sociopath" to highlight the damage these people caused in society.
Today, researchers are again using the term psychopath and sociopath is generally taken to refer to a less "dangerous" individual.
Sociopathy is linked to a set of behavior that is antisocial or violates social norms, while psychopathy is more broadly defined. In fact, it may surprise you to know that there is no medical diagnosis of psychopath - no psychiatric or psychological body will classify a patient as a psychopath.
Instead, the current approach to defining a psychopath is to use a set of criteria. The most commonly used checklist is the Psychopathy Checklist, Revised (PCL-R), created by Robert D. Hare.
Each of the 20 questions in the checklist is rated on a three-point scale and classification is usually completed during a face-to-face interview. High scores - over 30 in the United States and 25 in the United Kingdom - are said to label psychopaths.
Characteristics of a psychopath, derived from this and other tests, include: an uncaring attitude; a lack of emotions especially shame, guilt, and embarrassment; irresponsibility; insincere speech (from bending the truth to outright lying); overconfidence; selfishness; inability to plan for the future; and, violence or a low threshold for aggression.
The Psychopath Next Door
Pinning down how many people actually have psychopathic tendencies is difficult. Scientists can't exactly take a blood sample or measure brain activity. And the criteria are notoriously difficult to analyze. As such, it is difficult to know how many psychopaths there are in the world.
The FBI says perhaps 1 percent of the general population is a psychopath. A 2008 study from the University of North Texas and the University of British Columbia using the checklist found 1.2 percent of a US sample scored enough to indicate "potential psychopathy".
A 2009 UK report from Barts and the London Medical School, Queen Mary University of London reported a prevalence of 0.6 percent "potential psychopaths".
Higher scores were significantly associated with more violence, higher alcohol use, and estimated lower intelligence - the FBI states 10 to 15 percent of offenders in the criminal justice system are psychopaths.
But not all psychopaths are killers. And not all killers are psychopaths. Adolf Hitler, for example, was not a psychopath according to clinical forensic psychologist Glenn Walters because he didn't callously disregard feelings, he didn't lack impulse control, and he was not always egocentric.
Many psychopaths display their personality disorder not through murder but in their ability to lie, steal, hurt, cheat, and mislead others without feeling any shame, guilt or concern about the destruction or chaos they leave in their wake.
Many appear to be intelligent, charismatic and driven and they go about their everyday lives just like the rest of us. If there are 3.14 million psychopaths in the US, the chances are one could be living next door to you.
…And the Psychopath in the Boardroom
If we have an image of a psychopath in our head he (or she) probably won't be dressed in a suit making notes in a meeting.
But the scary fact is a high number of psychopaths hold positions of great power. Business leaders, lawyers, doctors and politicians can all be labeled psychopaths if you use a definition that broadly classes a psychopath as someone who is often intelligent and charismatic but feels no guilt or remorse when carrying out cruel or ruthless acts.
But surely psychopaths are more likely to be tracked down by the police than hold top office in business and politics?
Not so, say Paul Babiak, Ph.D., and Robert Hare, Ph.D. in their 2006 book "Snakes in Suits: When Psychopaths Go to Work."In business or politics, success is dependent in many cases on the ability to charm people, perform with confidence and go to great lengths to get what you want."
Many of the characteristics of psychopaths are valued in the business world.
In fact, 3 percent of corporate movers and shakers assessed in a 2010 study by HRBackOffice, Hopewell Junction, New York scored in the psychopath range - that's above the generally accepted incidence of 1 percent in the general population.
Are Our Children Psychopaths?
The high number of psychopaths can also be explained by the existence of psychopathy in children.
As many as one in 100 kids may be psychopaths, according to UK research in 2012 by University College London.
Psychologists are only recently recognizing that psychopathic children are different from the more common anti-social and aggressive kids.
Psychologists now put them in a distinct group, labeled "callous-unemotional" (CU), and believe that these children lack empathy and remorse and possess the ability to be ruthlessly cruel to other children, animals and adults.
The idea that children can also be psychopaths goes back to the 60s, when John M MacDonald described a trio of behaviors - bedwetting, animal cruelty, and fire starting - that were possible indicators of psychopathy when occurring together.
Bedwetting has since been ruled out as a significant sign and the trio of behaviors has largely been discredited. However, the connection between animal cruelty and psychopathy in later life is still important to many researchers.
Do Bad Parents Make Psychopaths?
The fact that children are sometimes labeled psychopaths brings up an important question. Are psychopaths born or bred?
Unlike children displaying other types of antisocial behavior, psychopaths are not the products of bad parenting according to 2012 research by University College London, UK.
In fact, researchers carrying out this study found a strong genetic link to psychopathy in kids. The scientists point out that children are not necessarily born to be antisocial or psychopaths but that some kids are born more susceptible to the environmental triggers that can cause problem behavior.
Robert Hare, creator of the psychopath checklist, has another view on the matter. He says that male psychopaths have a propensity to mate with many different women and subsequently abandon them, meaning there are a lot more children born to psychopaths than to non-psychopaths. These children, according to Hare, may inherit a predisposition to psychopathy.