Left out, but with some right benefits

It is beyond doubt that left-handed people have been a constant minority throughout human history. Right-handed individuals have historically enjoyed a distinct advantage over those who are left-handed.

Perhaps nowhere in the world has a serious census been carried out to measure the exact proportion of left-handers in national populations. There are also some people who are ambidextrous and can use both hands with ease. Most humans, however, have a dominant hand—and often a dominant side of the body—that they favour for routine tasks.

Every year, August 13 is celebrated as World Left-Handers Day. This day, then, is the right day to highlight the importance of left-handers in our society.

Facts first: There is no population on Earth where left-handers form a majority. Though they make up around 10–15 per cent of people, they often have to use scissors, desks, knives, and notebooks predominantly designed for right-handed use.

Left-handers have faced discrimination and suspicion, as reflected in language. In English, “right” also means “correct”. On the other hand, the etymology of the word “sinister” traces back to the Latin for “left”. In India, which remains orthodox in many ways, using the left hand for certain tasks is still considered inauspicious or a bad omen.

Being predominantly left-handed myself, I have often felt like an outsider in a right-handed world. For example, when I used to travel by city bus in the mornings, my natural habit of offering money with my left hand to buy a ticket was met with refusal—the conductor insisted it would “disturb” his work. Such experiences are common for left-handers in many areas of life.

A scientific survey published in 2005 in Neuropsychologia says that handedness may be determined at the early stage of development, in the womb itself. As Natalie Uomin, a senior scientist at the Max Planck Institute for Science, says, “If you know how the tool was held and how it was used, then you can look at the wear trace.” Several non-human species, such as other great apes, also show handedness, though the ratio there is closer to 50:50.

One leading theory explains why left-handers remain a small minority. “The idea is that in hand-to-hand combat or combat with weapons, there is an evolutionary advantage to being a minority left-hander,” says Uomin. 

If this hypothesis is correct, it would mean that although the disadvantages of left-handedness were significant enough to keep numbers low and keep us as a minority, the advantage in combat may have helped left-handers avoid extinction.

Some of the most prominent left-handers in history include, among others, Harry Truman and Barack Obama. India too has produced its share of remarkable left-handers.