OXFORD, England, Sept. 14 (UPI) -- A good belly laugh with others helps people feel less pain, but a polite titter has no effect, researchers in Britain found.
Lead author Robin Dunbar, head of the Institute of Social and Cultural Anthropology at the University of Oxford in England, said watching just 15 minutes of comedy -- "Mr. Bean" and "Friends" -- with others increased the pain threshold by an average of about 10 percent, compared to a group who watched TV clips on how to play golf.
"Very little research has been done into why we laugh and what role it plays in society. Using microphones, we were able to record each of the participants and found that in a comedy show, they laughed for about a third of the time, and their pain tolerance rose as a consequence," Dunbar said in a statement.
"We think that it is the bonding effects of the endorphin rush that explain why laughter plays such an important role in our social lives."
When people laugh properly, the physical exertion leaves them exhausted and triggers the release of protective endorphins -- one of the complex neuropeptide chemicals produced in the brain, that manages pain and promote feelings of well being, Dunbar explained.
The study said unforced laughter that creases the eyes -- not polite laughter which does not reach the eyes -- produces a series of exhalations without drawing breath, an involuntary physical mechanism that is limited to humans and appears to trigger the release of endorphins.
The study was published online in Proceedings of the Royal Society B.