However, there are some signs that you may not be aware are linked to psychopathic tendencies.
Mainly talk about food, money or sex
Most people enjoy a good chat about these topics, but psychopaths take it to another level.
Researchers at Cornell University compared stories of 14 psychopathic male murderers with 38 murderers who had not been diagnosed as psychopaths.
They found that when asked to discuss their crimes, the former group were twice as likely to discuss food, money and sex.
Whereas the non-psychopaths tended to use words relating to religion, family or spirituality.
Less likely to yawn contagiously
It's the age old thing isn't it? If you see somebody yawn, you can't help but do it yourself.
But according to researchers from Baylor University in Texas, students who scored highly for 'cold heartedness' were also less likely to yawn when others did, due to a lack of empathy.
Brian Rundle, a PhD student involved with the 2015 study, explained to The Times: "One of the biggest lines of evidence is that [contagious yawning is] very much related to empathy.
"While this is a really interesting finding, it doesn't mean that if you're not affected by a contagious yawn, there's something wrong with you.
"There's some evidence to show that in baboons, dogs, or chimps, the alpha male tends to yawn first.
"If you're sitting around the campfire, it cues everyone else to yawn, and instead of going to bed at separate times, they all do it simultaneously."
Increased hand gestures
Most people like being expressive with their hands when talking, but it is said that psychopaths often employ rapid up and down hand movements.
They may do this as a way to emphasise parts of their sentence that they want people to hear in a subtle manipulation tactic.
One example of this is from a police interview with murderer and rapist Paul Bernardo where FBI agents noticed he used powerful hand gestures to distract from his spoken lies.
Unusual sleeping habits
While others sleep at night, psychopaths tend to be kept up by highly stimulated minds.
In 2013, Australian researchers found that a preference for staying awake into the early hours was linked to anti-social behaviour and and 'Dark Triad' traits which includes narcissism, psychopathy and Machiavellianism.
Dr Paul Hokemeyer told Bustle: "Some psychopaths do have incredible minds that they need to keep highly stimulated."
Limited head movements
Researchers at the University of New Mexico in Albuquerque tested over 500 inmates to see if severe and long lasting antisocial behaviour was linked to head movements.
Those who had persisted in this behaviour were found to have more rigid head movements during recorded conversations.
Although historically head movements have been linked to deceptiveness, it's speculated that the rigidness may be a cover deployed by psychopaths.
The more you know, eh?
Topics: Mental Health
