Few things in life provide as much happiness as watching our baby smile at us for the first time. We feel goosebumps, run to find a camera to catch the moment, and pray that they will smile a second time. And yes, after a while, the baby does it again! They seem to perfectly understand that we want them to brighten our day with their happy face. And the funny thing about the matter is that, according to a study from the University of California, San Diego, babies consciously smile at their mothers, because they expect them to return the expression.