Psychopathy – the absence of empathy or caring about other people – is characterised by a number of traits, such as being selfish, manipulative and having an antisocial lifestyle.
There are a number of ways to spot a psychopath, such as lack of empathy, superficial charm and self-centered impulsivity.
However, there are also some more straightforward methods to do with physical behaviours, scientists have found over recent years.
Immunity to contagious yawning....
Tests showed lower yawn frequency was associated with having less empathy...
Poor sense of smell
By Hannah Osborne
Via Edwin Rutsch