What Makes a Person Left- (or Right-) Handed?
Scientists aren’t sure why some people turn out to be left-handed. But they have noticed that being left-handed runs in families. So they’re pretty sure your genes, or DNA, influence whether or not you turn out a lefty. Since you get all your genes from your parents, you might be left-handed because your parents are lefties. But genes can’t be the whole story because some kids have right-handed parents and still end up being left-handed. Getting hurt can also make a person a lefty. Sometimes righties badly injure their right hand and can’t use it anymore. Those kids and adults usually learn to use their left hand and become lefties. A lefty can also become right-handed if they hurt their left hand. So it works both ways.
