Babies time their smiles to make their moms smile in return

Why do babies smile when they interact with their parents? Could their smiles have a purpose? A team of computer scientists, roboticists and developmental psychologists confirm what most parents already suspect: when babies smile, they do so with a purpose -- to make the person they interact with smile in return. To verify their findings, researchers programmed a toddler-like robot to behave like the babies they studied and had the robot interact with undergraduate students.