It's almost instinctive -- you see an adorable baby, and you start to coo, smile or make a face to elicit some kind of response. But even if you get a blank stare back, rest assured that the tyke is processing every change in the shape and rhythm of your mouth and face. Researchers, led by Whitney Weikum at the University of British Columbia, found that infants under 8 months old may rely on such visual cues to learn language, even using variations in facial expressions to distinguish one language from another.
Working with babies raised in two different language environments--one...