Where have all the lefties gone?
Star Tribune, March 4, 1993
Lewis Cope

About 13 percent of Americans are left handed, but only about 5
percent of those in their fifties are left handed. A recent study by
Robert Glynn concluded that left handed people live as long as
right-handers suggesting that the fact that their are fewer left
handers among older people can be accounted for by pressure to
become right handed. The author of earlier studies which claimed
that left handers live less long, Stanley Coren, believes that left
handers have a higher rate of deaths from accidents because tools,
driving customs etc. favor right handers.

The fact that there are a higher proportion of left handers among
younger people and that younger people have a higher proportion
of accidents has allowed both Coren and Glynn to claim that the
other has not answered the question. Coren can claim that Glynn,
by limiting himself to subjects over 65, has taken out the very
group where the danger of being left-handed has an effect. Glynn
can claim that Coren by not controlling for age will necessarily
find a shorter lifetime for left handers just because there are more
left handers among the younger people and younger people have a
higher accident rate.