Why Aren't More Human Beings Left-Handed?

About one out of every ten human beings is left-handed. That might seem like a fitting percentage for a not-so-dangerous abnormality to be produced, but the truth is scientists really have no idea why that figure isn’t zero or one hundred or fifty. In fact, individual apes use whatever hand they feel like during any given task depending on the day, their mood or random chance, and while cats and dogs typically have a dominant paw, it’s actually split pretty evenly down the middle in large sample pools.

So, the question is why ten percent of human beings are naturally predisposed to careers as baseball relief pitchers. SciShow host Hank Green decided to tackle the querry this week, and he actually found a slew of different theories. There are some scientists who think left-handedness was phased out by evolution as a way to allow early human beings to share tools. There are others who think it has to do with the side of our brain controlling written language also controlling the right hand, and of course, there are others who are unhappy with both of these theories.

Hank’s brother John Green runs the YouTube show Mental Floss. Together, it’s quite possible there’s no brother duo offering better Internet content than these two. Here’s to hoping that lofty achievement continues.