I think it’s more than coincidental that the sound repertoire of babbling babies, compared with the speech sounds in a diversity of languages across the world, lends credence to the idea that there was a mother tongue that goes back to prehistoric times. Readers of the Bible will recall that it was after the fall of Babel that people separated and spoke in many languages. (Our language contains the interesting coincidence of Babel and babble having the same sound but a slight difference in spellings.) Students of language, such as myself, are fascinated by the occurrence in diverse languages of words that bear remarkable similarity to each other. It would be interesting to study the idiosyncratic speech that often develops with twins to see if the language they develop bears similarities to the language we speak in all or any respects.
Newton Centre, Mass.