My new daughter is now two months old, and she has just discovered that she controls her own hand. My older daughter did the exact same thing at around the same age. She would make a clenched fist and hold it up in front of her like a demagogue giving a speech. She would stare at it for twenty minutes or half an hour at a stretch, awestruck at her control of this amazing hand.

Daughter number two isn't quite such a rabble-rouser. She doesn't just hold her fist up and stare at it triumphantly. Instead she clenches a fist, looks at it, then stretches it out toward her toes while following it intently with her gaze. Then she lifts it up again, looks at it again, and stretches it again.

It's almost like she's conducting a scientific experiment: Can I really control this thing? Okay, let's see. Can I lift it up? Check. Can I stretch it out toward my toes? Check. Can I duplicate the results? I'll repeat the experiment!

I looked it up this morning and apparently all babies do this. They even have a word for the behavior- it's called “hand regard,” and apparently it happens when the baby first starts noticing that she has conscious control over her limbs.

It's pretty neat, when you think about it. We aren't actually born with the understanding that we control our own bodies. That's something we have to figure out by trial and error, and a process of painstaking experimentation.