Whether you’re right-handed, left-handed or ambidextrous, there’s a good chance you’ve come across the alarming statistic that the life expectancy of left-handed people is nine years shorter than the life expectancy of right-handers.
The reality, however, is that although left-handed people may be slightly more likely to incur minor injuries while living in a world designed for right-handers (think scissors and can openers), there appears to be no statistical difference in life expectancy based on handedness.
The nine years statistic comes from research conducted in the late 1980s by Diane Halpern and Stanley Coren, based on their examination of lists of deaths that had taken place in the Southern California. To determine whether handedness had a role in life expectancy, the researchers asked relatives whether the deceased had been right-handed or left-handed. They found that the average age of death was around nine years younger for left-handed people than right-handers, leading to the conclusion that left-handers are more likely to suffer from serious accidents as well as fatal physiological factors related to their left-handedness.
Over the years, however, other studies have contradicted these findings. The problem with the original research is that the prevalence of reported left-handedness increased during the 20th century. It became much more acceptable for naturally left-handed children to remain left-handed, whereas earlier in the century, many left-handers were forced to learn to write with their right hand and ultimately identified as right-handed for the rest of their lives.
Thus, when Halpern and Coren conducted their research, many people who died at an old age and were naturally left-handed were included among the right-handers, as they had identified as right-handed. Conversely, due to the growing acceptability of left-handedness over time, when looking at people who had died at younger ages, there would have been comparatively more left-handers among them. Thus, the mistaken conclusion that few left-handers were achieving the same longevity as right-handers, leading to the life expectancy myth.
Rightie or leftie?
- Left-handedness became less common in the 19th century as more children were given access to formal schooling – albeit schooling that forced them to write with their right hand. The growth of factories, with nearly all machines designed for right-handers, also contributed to fewer people using their left hand, even if it was naturally dominant.
- Chris McManus, a professor at University College London who conducted extensive research on handedness for his book Right Hand, Left Hand has compared a 9 year drop in life expectancy to “smoking 120 cigarettes daily plus doing a number of other dangerous things simultaneously.”
- The natural rate of left-handedness is around 10% or 11%, but back in 1900, it was artificially pushed down to around 3%, before rising gradually during the 20th century.
- Barack Obama, Prince William, Oprah Winfrey, Paul McCartney, and Julia Roberts are among the world’s most famous left-handers.
