Left-Handed People Die Younger

The claim comes from a real 1991 study by Halpern and Coren, which found that left-handed people in their sample had died, on average, nine years younger than right-handed people, a result that got picked up widely in both popular media and serious scientific journals. The problem turned out to be the study's method, not its data: because social pressure to write with the right hand was strong for most of the 20th century, many people alive earlier in the century who were naturally left-handed had been forced to switch, meaning genuinely left-handed people were undercounted among older, longer-lived generations in the sample. That created the statistical illusion of left-handers dying young, when really there were just fewer of them left to count among the elderly. Later, better-designed studies, including one tracking twin pairs of opposite handedness, found no real difference in lifespan tied to handedness at all.