Chances are you know somebody who’s left-handed. But do you really know them? Left-handedness might not be a defining characteristic, but lefties do have struggles that righties don’t. If you do know a lefty, you’ve seen the smudges on their hands from writing in pen, and you’ve heard the grunts and groans of them trying to open a can of soup. However, lefties have more going on than anybody realizes. It’s a fascinating quirk of human evolution that we’ve developed a preference for one hand over the other, but more than that, it has all kinds of unexpected effects on us. Who knew?