Left-handed people make up 10 percent of the human population on average, but chances are you know a southpaw. Why some people are left-handed has always been a bit of a puzzle, but researchers have found some interesting defining leftie characteristics that highlight the differences from the right-handed majority. Here are just a few of them.
1. They're over-represented in athletics. Maybe you've seen a leftie pitch a baseball game or win a tennis match and wondered why left-handers seem to be so prevalent in the sports world. It's because of the element of competition, according to a study from Northwestern University. Researchers found that left-handed people are a result of the balance between cooperation and competition in human evolution. Cooperation favors same-handedness, such as for sharing tools, whereas competition favors surprise, and a left-handed person might win in a fight, the study said.
The Northwestern scientists built a mathematical model that "can predict accurately the percentage of left-handers in a group — humans, parrots, baseball players, golfers — based on the degree of cooperation and competition in the social interaction." They claim their model accurately predicted the number of left-handed athletes in baseball, boxing, hockey, fencing and table tennis — in which southpaws numbered well above 10 percent (and up to 50 percent for baseball players).
2. They're more likely to have a slender face. According to a (somewhat odd) study, people with slender lower faces are 25 percent more likely to be left-handed. Those slender-jawed folks also are more susceptible to tuberculosis, for what it's worth.
3. They're good at math. Have you ever noticed the lefties in your life are particularly quick with arithmetic? While a link between mathematical ability and left-handedness has long been rumored, a 2016 study found a "moderate, yet significant correlation" between the two. Math scores were five to 10 percent higher among lefties in a study of 2,300 students in Italy between the ages of 6 and 17 who were asked to complete simple mathematical tasks and problem-solve.
Also, a 2006 study published in the journal Neuropsychology found that left-handed people were more likely to have faster connections between the right and left hemispheres of the brain, meaning they processed information faster. Researchers said this could be a beneficial skill in areas like video games or sports.
Lefties like this batter are over-represented in athletics. (Photo: Richard Paul Kane/Shutterstock)
4. They're less likely to be ' left-hemisphere dominant.' For 95 percent of right-handed humans, the left side of the brain is their dominant side and where language function is localized, reports Psychology Today. However, for lefties, only 70 percent are left-hemisphere dominant, with the remaining 30 percent distributing language ability across both sides evenly or moving it to the right side of the brain.
5. They're slightly more susceptible to allergies, migraines and some diseases. Left-handedness is a result of biological diversity, and while lefties may have the advantage in a fight, they may have disadvantages in other areas. For example, this study found that left-handed people may be predisposed to allergies earlier in life. And the New York Times reported on a series of studies that showed "left-handed people are more likely to suffer from learning disabilities, stuttering, migraine headaches and, according to the latest findings, autoimmune diseases, like ulcerative colitis, myasthenia gravis and celiac disease, in which the body attacks its own tissues."
...[ Continue to next page ]
Comments