To test the theory, student volunteers placed their hands in a bucket of ice cold water while swearing repeatedly.
They then repeated the exercise but, instead of swearing, used a harmless phrase instead.
Researchers found that the students were able to keep their hands submerged in the icy water for longer when repeating the swear word - establishing a link between swearing and an increase in pain tolerance.
They also found that the pain-numbing effect was four times more likely to work in the volunteers who did not normally use bad language.
The team believes the pain-lessening effect occurs because swearing triggers the ''fight or flight'' response.
The accelerated heart rates of the students repeating the swear word may indicate an increase in aggression, in a classic fight or flight response of ''downplaying feebleness in favour of a more pain-tolerant machismo''.
The research proves that swearing triggers not only an emotional response, but a physical one too, which may explain why the centuries-old practice of cursing developed and why it still persists today.
Dr Richard Stephens, who worked on the project, said: ''Swearing has been around for centuries and is an almost universal human linguistic phenomenon.
''It taps into emotional brain centres and appears to arise in the right brain, whereas most language production occurs in the left cerebral hemisphere of the brain.
''Our research shows one potential reason why swearing developed and why it persists.''