SWEARING can lessen the feeling of physical pain, scientists have discovered.

Volunteers withstood pain for longer when they swore compared with when they used anodyne words, in a study at Keele University in the English Midlands.

Dr Richard Stephens, who led the study at the university's school of psychology, believes it may explain why most languages contain swear words.

"It could be part of the flight or fight response," Dr Stephens said.

"The volunteers who swore had an elevated heart rate, so it could be increasing their aggression levels.