- A psychopath’s pupils do not dilate when they look at distressing or sad scenes
- This is the exact opposite behaviour as is expected for a non-psychopath
- Most people experience some empathy and their pupils dilate as a response
- Researchers say this shows psychopathy is not associated with an overall difficulty in responding to emotion, but insensitivity to threatening information
Experts discovered that the eyes of people that suffer from the personality disorder have a unique reaction to horrific scenes – their pupils do not widen. Pupils of non-psychopaths dilate when they see upsetting or distressing images as part of a natural response.
While the eyes of a psychopath behaved abnormally when looking at distressing scenes, the researchers were amazed when they saw their eyes behaved normally when looking at positive pictures.Lead author, Dr Dan Burley, from Cardiff University’s School of Psychology, said: ‘Our findings provide physical evidence of an emotional deficit common to psychopathic offenders.