There's one simple physical sign that suggests someone is a psychopath, according to study

When someone says the word 'psychopath', you may have an image of what that might be in your head, from Jeffrey Dahmer to Ted Bundy. But it isn't as black and white as you may think.

What is a psychopath?

All psychopaths are thought to have a severe form of antisocial personality disorder, which is explained by the NHS as a 'particularly challenging type of personality disorder' that can be 'characterised by impulsive, irresponsible and often criminal behaviour.'

The NHS further explains: “Someone with antisocial personality disorder will typically be manipulative, deceitful and reckless, and will not care for other people’s feelings.”

It also explains that someone with the disorder may exploit, manipulate or violate other people without any concern or regret about their feelings, while dealing with anger control issues and blaming other people for their own problems.

Basically, they are deeply and unequivocally unpleasant.

Ted Bundy might spring to mind when you think of a psychopath. (Bettmann/Contributor).

The one tell-tale sign

Although, there is a way to identify a psychopath through one specific action, and almost anyone can pick it out if you look hard enough.

A study that was published in the 200th Personality and Individual Difference journal back January suggested there was one physical sign that could indicate someone is a psychopath.

Apparently, the one sign to look out for is to do with head movements.

A study has suggested that head movements are key. (Getty stock photo)

The study's authors found that people with the condition move their heads less when speaking to those with lower levels of psychopathy.

It was discovered that this form of communication was common in men with antisocial personality disorder, but it was also found to be just as common in women as well.

As stated previously by IFLScience: “Prior work has identified a number of surprising tell-tale signs in the body language of psychopaths.”

According to the study, men with high levels of psychopathy also use more hand gestures than those with lower scores, and short bursts of blinking have also been found in those with higher levels.

However, as expected, there are a number of other signs linked to psychopathy that can be spotted in adults.

There are a number of signs. (Curt Borgwardt/Sygma via Getty Images)

What are the other main signs of psychopathy?

• Care-free responses to others’ suffering or distress
• Does not show remorse after hurting others or breaking rules
• Pathologically lies
• Manipulates people to get what they want
• Often engages in risky or dangerous activities
• Tends not to plan ahead, leaves things until the last minute
• Fails to keep promises or follow through with plans as they are irresponsible
• Superficially charming
• Doesn’t seem to care about performance at school or work
• Frequently brags
• Struggles to maintain relationships, such as friendships and romantic relationships
• Possibly engages in violent or illegal behaviour

It's important to not, however, that there are other reasons why people choose to be violent or part-take in illegal/criminal activities and simply displaying a couple of the traits doesn't mean your mate is a psychopath.