[now we know why Obama terrifies some people while others just chuckle]
Horror film gene makes some scream while others laugh
The secret of why horror films make some people scream in terror while others may simply laugh has been revealed
By Stephen Adams
Telegraph 0 UK
11 Aug 2008
Scientists say different versions of a single gene linked to feelings of anxiety can explain the way in which some people simply cannot abide such movies, while others enjoy the suspense and the gore.
The findings may explain why it is that over the past 35 years people have had wildly different reactions to the classic horror film, The Exorcist.
While many screamed and some even fainted in cinemas at scenes of spinning heads and shaking beds, others simply laughed.
A particular variant of the ‘COMT’ gene affects a chemical in the brain that is linked to anxiety, they have found.
People who have two copies of one version of the gene are more easily disturbed when viewing unpleasant pictures, the scientists discovered.
That version of the gene weakens the effect of a signalling chemical in the brain that helps control certain emotions.
The scientists found that those carrying two copies of it were significantly more startled by frightening images than others.
By contrast, those who had one copy of the gene and one copy of another version were able to keep their emotions in check far more readily.
The study, published today in the scientific journal Behavioural Neuroscience, also found that those with two copies of the latter gene were also able to keep a lid on their anxiety more easily.
Researchers from the University of Bonn in Germany made the discovery after testing 96 women.
Then they showing them three different types of pictures – emotionally “pleasant” ones of smiling babies and cute animals, “neutral” ones of items like electric plugs or hairdryers, and “aversive” ones of weapons or injured victims.
The Exorcist was banned by some councils in Britain upon its release here in 1974, but broke box office records in the US to become the biggest selling horror movie of its day.
Psychologist Christian Montag, one of the University of Bonn researchers, said he thought the gene variant linked to scaring more easily had only recently evolved, as it was not present in other primates like chimpanzees.
He said the propensity to scare more easily could have offered an evolutionary advantage to humans.
While bravery appears to be prized in the animal kingdom, recklessness could have been a disadvantage to humans with their larger mental capacity to go away and figure a problem out.
Mr Montag said: “It was an advantage to be more anxious in a dangerous environment.”
However, he said a single gene variation could account for only some of people’s anxiety differences, otherwise, up to half the population would be anxious, he said.
“This single gene variation is potentially only one of many factors influencing such a complex trait as anxiety,” he said. “Still, to identify the first candidates for genes associated with an anxiety-prone personality is a step in the right direction.”