Not very many years ago, it was common for language researchers and theorists to argue that language development was somehow special and separate from other aspects of development. It was a period when the "1 ittle 1 inguist" view of language development was common, and much discussion was devoted to develop mental "linguistic universals," in contrast to more broadly defined cognitive universals. It seemed to me at the time (and still does) that such views reflected more their promulgators' ignorance of those aspects of cognitive development most likely to provide illuminating parallels with...