Here are a few of the most interesting facts about lefties (and by the way, this answer was written by a lefty):
Overall, eight of the 45 American presidents have been lefties (the others are James Garfield, Herbert Hoover, Harry Truman, and Gerald Ford).
Lefties make up about 10 percent of the general human population. Some researchers believe that right-handedness became much more common than left-handedness because humans rely on social collaboration—like using the same tools—to survive.
For much of human history, left-handedness was associated with negative personality traits. In the Middle Ages, “the Devil himself was considered a southpaw, and he and other evil spirits were always conjured up by left-handed gestures,” per TIME Magazine.
The word “sinister," which means harmful or evil, derives from the Latin and Old French words for “left” or “on the left side.”
So, why were lefties shunned? Some researchers believe that anti-lefty bias was pragmatic. Most tools were designed for right-handed people, so societies encouraged people to use their right hands, regardless of their individual preferences. Over time, that bias turned into superstition.
Lefties have a significant advantage in many sports. One study found that over 50 percent of elite baseball players are left-handed, and lefties are also overrepresented in boxing, fencing, and table tennis. This isn’t because lefties are more athletic—these sports have built-in biases that favor lefties.
The idea that lefties are more creative is a myth. Generally speaking, lefties aren’t more “in their right brain" than righties, they’re no more artistic, and they’re no less logical than their right-handed counterparts.
However, lefties' brains are often organized differently. But again, it’s not believed to affect intelligence, creativity, or any other cognitive functions.
Older mothers are more likely to have left-handed babies. This comes from a 1990 study from the University of British Columbia in Vancouver, which surveyed 2,228 first-year university students.
Per the research, mothers aged between 30 to 35 have a 25 percent higher chance of having left-handed children, while mothers aged 35 to 39 had a 69 percent increase. When mothers were over 40, their children were 128 percent more likely to be lefties.
Why might that be? Well…
Left-handedness might be more common in stressful pregnancies. Research shows that birth stress and birth risk factors are associated with an elevated percentage of left-handedness. In other words, the more difficult the birth and pregnancy, the higher the chances that the baby will be a lefty.
Left-handed people seem more likely to have schizophrenia and other mental disorders. A 2013 study found that lefties were more likely to have psychotic disorders. However, their left-handed brains aren’t necessarily more prone to developing these conditions; since left-handedness is linked to prenatal and perinatal stress, it’s possible that birth conditions are the cause.
One study found that lefties are less likely to be financially successful. Harvard researcher Joshua Goodman led the study, which found that lefties are 2.4 percent more likely to end their education after high school. On average, American lefties earn 6 percent less than righties, which means an income of about $1,300 less per year.