My three-year-old son and one-year-old daughter were playing in the living room. The toys from their little toy box were strewn all over the floor and under every piece of furniture in the usual minefield fashion. The toy box was turned upside down and the kids were taking turns jumping off of it. As I watched them to make sure no bones were being broken, it struck me just how much my daughter was able to keep up with her big brother. When he was her age, he wasn’t nearly as daring. But the only reason she could keep up with him was because he was setting an example. He was pushing her, sometimes literally, to do what he was doing as well and as fast as he was doing it.