Fifteen years ago, psychologists Barbara Rogoff and Maricela Correa-Chavez ran a simple experiment. They wanted to see how well kids pay attention — even if they don't have to. They would bring two kids, between the ages 5 to 11, into a room and have them sit at two tables. Then they had a research assistant teach one of the kids how to assemble a toy. The other kid was told to wait.