Lefties appear to have shorter average life spans than right-handed people, researchers said Wednesday.

An examination of nearly 1,000 death certificates in two Southern California counties - combined with information from survivors - found that being left-handed appears to translate into an average nine-year reduction in life span."When we turn to the effect of handedness on life span, the results are striking in their magnitude," the researchers reported in a letter published in The New England Journal of Medicine.

The study found the right-handed people in the study tended to die at age 75, compared to age 66 among the left-handers, the researchers said.

Diane Halpern of the California State University in San Bernardino, who helped conduct the study, said the findings are consistent with a previous study she helped conduct on professional baseball players that also found a life span advantage for right-handers.

"But in that case, the difference was fairly small," she said. "In this new study, we were really surprised by the size of the difference we found in life span between the two groups."

Although it has long been known left-handers suffer from a variety of disorders at a greater rate than right-handers, the only clear reason the researchers could find for a portion of the life span disparity was a much larger accidental death rate among lefties, she said.

Among the 987 cases included in the study, death due to accident was listed nearly six times more often for left-handers than right-handers, she said.

Stanley Coren of the University of British Columbia, said left-handed men appear to be prone to dying from industrial accidents and car crashes.

A study he conducted found left-handed men were significantly more likely than right-handed men to die from injuries suffered in car crashes or using tools.