Face time: here’s how infants learn from facial expressions
For example, when infants who are first learning to crawl and walk are presented with a possibly dangerous slope, they look to their mothers’ facial expressions for cues. They attempt to descend the slope only when their mothers offer an encouraging smile; they refuse when their mothers discourage them from going.
Similarly, toddlers avoid new toys when mothers pose a fearful facial expression toward them. But they happily approach new toys when mothers show a smiling face.
.. Perhaps even more surprising is that infants prefer the faces of their own race by three months of age, and have trouble distinguishing between faces of other races by nine months.
Researchers call this phenomenon “perceptual narrowing”: it means that newborns’ brains are flexible enough to distinguish between a variety of different faces (even faces of different species) right from birth.
But as they become experts at identifying the faces they see most often, they lose the ability to differentiate between faces that look different from the ones that are most familiar to them. In other words, they begin to have trouble deciding whether two faces of a different race are the same person, or two different people.
.. The good news is that exposure to people from other races on a daily basis can erase this effect.