Most of us could easily distinguish between spoken English and French. But could you tell the difference between an English and a French speaker just by looking at the movements of their lips? It seems like a difficult task. But surprising new evidence suggest that babies can meet this challenge at just a few months of age.

Young infants can certainly tell the difference between the sounds of different languages. Whitney Weikum and colleagues from the University of British Columbia decided to test their powers of visual discrimination.

They showed 36 English babies silent video clips of bilingual French-English speakers reading out the same sentence in one of the two languages. When they babies had become accustomed to these, Weikum showed