How does a baby's brain develop? Do you plop them in front of some Baby Einstein DVD's with a Mozart soundtrack? Hell no. The brain is designed for movement, and movement is what wires it up. To grow a child's brain, give them a safe place to play.
Here's an amazing video of Charles-Edward, a nine month old boy who knows how to go to work. Check out what he does when given four hours to play in a room full of toys. Filmed and time lapsed down to two minutes by his father Francis:
Beautiful. Well done Charles, you are well on your way to world domination.
What may look like chaos here is actually a series of highly controlled movement experiments performed one after the other by a master scientist. Every second Charles is making a plan, checking the results, comparing the resulting data to expectation, and then making adustments for the next round of experiments.