Does speech--that uniquely human trait--come from our genes, or is it learned? Luminaries such as linguist Noam Chomsky of the Massachusetts Institute of Technology have championed the role of evolutionary inheritance over that of culture. But for many years, proponents of this position could only look to languages themselves for evidence. They observed that many tongues share grammatical structures and other attributes, bolstering the argument that speech is innate. The suspicion that a "speech gene" might exist, however, remained unresolved. Then, in 1990, something extraordinary happened.
It could not have been a coincidence that a particularly large number of children from one family showed up at an English speech therapy school. The children mumbled almost unintelligibly and stumbled over grammar--they could not, for instance, describe events in a correct chronological order.