Between 10 percent and 12 percent of the world's population is left-handed, and scientists have no idea why. It could be genetic. It could be due to damage in utero. And while there are no obvious differences between those who are right-handed and those who are left-handed, we do know that lefties tend to excel at visual and spatial tasks and seem to be overrepresented among geniuses, reports LiveScience.com. What makes southpaws special? Here are ten facts:
1. Just as humans favor one hand over the other, animals also favor one paw over another. But unlike humans, which paw is favored is split about 50-50.
2. Although there is likely a genetic component involved in handedness, environment is also important. For example, researchers have found that identical twins often have different dominant hands.
3. Studies have found that southpaws have higher rates of dyslexia, schizophrenia and autoimmune diseases, such as allergies and lupus.
4. Males are overrepresented among lefties, so some scientists theorize that exposure to testosterone in the womb may affect handedness.
5. Many geniuses and leaders are lefties. Albert Einstein, Benjamin Franklin, Isaac Newton and Charles Darwin were all southpaws, as well as eight U.S. presidents: James A. Garfield, Herbert Hoover, Harry S Truman, Gerald Ford, Ronald Reagan, George H.W. Bush, Bill Clinton and Barack Obama. Fully 25 percent of the Apollo astronauts were left-handed.
6. Lefties tend to excel in fields that require excellent visual-spatial abilities, including architecture and graphic design, but are underrepresented in math and science.
7. Being left-handed can be an advantage in a fistfight when a surprise left hook can be a decided benefit. As many as 45 percent of expert fencers and tennis champions are lefties.
8. Lefties may have a more balanced view of their bodies. Right-handed people are more sensitive to their right side; for example, their right arm is typically stronger and larger. Left-handed people don't have a similar bias; for example, their arms are equally strong.
9. Mothers who are over 40 at the time of a child's birth are 128 percent more likely to have a left-handed baby than women who give birth in their 20s.
10. August 13 is Left-Handers Day, which celebrates left-handedness and raises awareness of the difficulties and frustrations lefties endure in a right-handed world.