There is a questionnaire, the Self-Report Psychopathy Scale, which assesses psychopathic traits in the general population. There are twenty-nine statements, and the respondent indicates the extent to which each statement applies to them, from “strongly agree” to “strongly disagree”. Early in my PhD, a friend asked if he could see the questionnaire. He read out one of the items: ‘I sometimes tell people what they want to hear.’ He looked concerned. ‘But I would agree with that – I do that sometimes,’ he said. ‘Does that make me a psychopath?’ I reassured him no, it did not - only someone who scored very highly on most of the statements might meet criteria for what we think of as a “psychopath”. But he had hit on something important: very few people score zero on the questionnaire.

Can an online quiz spot a psychopath? Read more

Have you ever lacked empathy in certain situations, or for certain people? What about lying, or cheating, or breaking the rules for the fun of it? Almost all of us can identify with at least some element of psychopathy. In fact, in some situations, moderate levels of psychopathic traits can even be helpful. For example, a surgeon who is able to be emotionally detached from his patient may operate on them more effectively. In the business world, manipulating and cheating others while promoting yourself may be one strategy to reach the top. Whether it is a tendency to charm others, a desire to take risks or an inclination to have one night stands, most people endorse some aspect of psychopathy.

In its full-blown form, psychopathy is a highly destructive personality disorder. It combines antisocial and sensation-seeking behaviour (aggression, substance abuse, thrill seeking) with cold-hearted social and emotional traits, such as a lack of empathy or guilt and a willingness to manipulate others. It is this cold emotional persona that makes individuals with psychopathy so dangerous. The things that commonly stop people from committing crimes - victim empathy, guilt, fear of punishment – do not serve as “brakes” in this group. Individuals with psychopathy are entirely unconcerned by the effect their behaviour has on others. They present a charming front whilst manipulating and abusing others to get what they want, and then readily drop anyone who is no longer useful to them. When we read about individuals with very high levels of psychopathic traits, we are frightened and fascinated by their behaviour: who are these creatures, so inhumane, so different from us – and what allows them to treat others the way they do?

But here’s the scariest thing of all: psychopathic traits do not only exist in people that have the full manifestation of the personality disorder. This is because, like all mental illness, psychopathic traits exist on a continuum that runs throughout the population. The vast majority of us have endorsed at least some element of psychopathy. In the general population, the distribution of psychopathic traits is skewed, meaning that most people have relatively low levels of these traits, with smaller numbers of people endorsing gradually higher levels. People with varying levels of psychopathic traits sit in our train carriages, work in our offices, and live in our homes. Psychopathic traits are not reserved for prisons or psychiatric hospitals; all of us lie somewhere on the “psychopathic spectrum”.

Researchers are currently trying to understand what determines where you end up on the spectrum. Genetics play a role: we know that some people are born with a predisposition towards developing psychopathic traits. That’s not the full story though. Environmental factors are also important – things like how much violence there was in your community as a child, or the kind of parenting and friends that you had. Like so many aspects of our personality and behaviour, psychopathy is not simply a question of nature versus nurture, but a complex interplay between the two.

Psychopathy is not a pathway set in stone, a destination set at birth that cannot be altered. Recent research suggests that some interventions – like supporting the parents of children have high levels of these traits – may help to reduce levels of psychopathy. As the field moves forward, we hope to increasingly have access to interventions and treatments that can reduce the severity of psychopathic traits.

At present, however, there remains a great many people – in prisons, psychiatric hospitals, and our day-to-day lives – who exhibit very high levels of psychopathic traits and wreak havoc on those around them. But it is critical to remember that these individuals that are called “psychopaths” are not different beings to us entirely. Instead, they are simply people with more extreme versions of traits and behaviours that we all have and understand. Of course, the behaviour of some of these individuals – murder, torture, rape – is utterly abhorrent, and it is right that we find it difficult to comprehend. But in reality, this behaviour, like all human behaviour, is a matter of degree. Psychopathy is simply the awful endpoint of a line on which we all stand.