Have you ever wondered why you laughed so hard and loud when you last watched Jerry Seinfeld, Terry Fator or a Russell Peters show? Well, a new study appears to have an answer - it suggests it has something to do with psychotic personality traits in the comedians.

A study published in the British Journal of Psychiatry, Thursday, suggests that comedians can make people laugh because they have personality characteristics that are often found in people who have psychotic disorders (read: crazy). Does that make comedians scary or funny?

Researchers from the University of Oxford and Berkshire Healthcare NHS Foundation Trust had asked 523 comedians to answer the O-LIFE Questionnaire, a four scale test that would measure an individual's psychotic traits. The researchers also asked 364 actors and 831 people who do not have creative jobs to complete the questionnaire. The results showed that the comedians have high levels of extroverted and introverted personality traits and scored significantly higher on all four aspects of psychotic-proneness than the two control groups.

Researchers believe it is their extraordinary personality trait that gives comedians their talent to entertain. "The creative elements needed to produce humor are strikingly similar to those characterizing the cognitive style of people with psychosis - both schizophrenia and bipolar disorder," said Gordon Claridge, a professor at Oxford University's department of experimental psychology. "Although schizophrenic psychosis itself can be detrimental to humor, in its lesser form it can increase people's ability to associate odd or unusual things or to think 'outside the box'. Equally, 'manic thinking', which is common in people with bipolar disorder, may help people combine ideas to form new, original and humorous connections."

Paul Jenkins, CEO of the charity Rethink Mental Illness, however, has advised against stereotyping comedians. "Mental illnesses like schizophrenia can affect anyone, whether they are creative or not. Our knowledge and understanding of mental illness still lags far behind our understanding of physical illnesses, and what we really need is much more research in this area," Jenkins said.

James McCabe, a senior lecturer at the Institute of Psychiatry in London also said that the findings of the study should not be taken as evidence of link between comedic talent and mental illness. "Psychosis is not a problem with personality, it's a more severe disorder than that. People with psychosis and schizophrenia have a very impaired ability to appreciate humorous material," he said. "This study tells us some interesting things about the differences between comedians and actors but not about the link with psychosis."

Oh, well...