Psychologists found that people who watched an eight minute clip from a scary movie suffered more symptoms associated with post traumatic stress if they were left handed than if they were right handed.

When asked to recall events from the film clip, taken from near the tense climax of thriller Silence of the Lambs, left handed volunteers gave more fragmented accounts filled with more repetition than their right handed counterparts.

This effect is common in people suffering from Post Traumatic Stress Disorder.

The scientists now believe their results could provide new insights into how people develop post traumatic stress and the way the brain deals with fear.

Dr Carolyn Choudhary, who led the research at Queen Margaret University in Edinburgh, said: "The prevalence of post traumatic stress disorder is almost double in left handers compared to right handers.

"We used a portion of film from Silence of the Lambs that we know elicits fear, so we could check the recalled account against the film. People who were left handed showed significantly more fragmentation in their memories and more repetition.

"It seems that after experiencing a fearful event, even on film, people who are left handed had subtle behaviours that were like people suffering from post traumatic stress disorder."

Silence of the Lambs, starring Anthony Hopkins as serial killer Hannibal Lector and Jodie Foster as FBI agent Clarice Starling, is widely regarded as one of the most tense thrillers ever made.

Participants who were left handed showed more signs of symptoms found in patients suffering from post traumatic stress disorder after watching the eight minute clip from the movie.

Dr Choudhary, who will present her findings at the annual conference of the British Psychology Society this week, added: "The mistakes they made were subtle errors in verbal recall.

"It appears these are tied to the way the brain makes memories during fearful experiences.

"It is apparent the two sides of the brain have different roles in PTSD and the right hand-side of the brain seems to be involved in fear. In people who are left handed, the right hand side of their brain is dominant, so it may have something to do with that.

"We need to do more experiments to understand what exactly is going on here."