Brain

The brain is basically built from the bottom up. First the brain builds basic circuits that are responsible for basic skills, and then more complex circuits are built on top of those basic circuits as we develop more complex skills. Biologically, the brain is prepared to be shaped by experience. It's expecting the experiences that a young child has to literally influence the formation of its circuitry. It's built into our biology. The interaction between genetics and experience that shapes brain architecture is embedded in the reciprocal relationships that children have with the adults in their lives. And by that we mean what we refer to as the serve and return nature of children's interaction with their adults. Development and the impact of experience on development is not a one-way street. It's a back-and-forth interaction.