Universalism was most prominently set forward by the linguists Joseph Greenberg and Noam Chomsky. Chomsky, attempting to account for the celerity with which children grasp the subtle grammatical rules of their native tongues, argued that the best explanation is that the human brain has "modules" capable of generating an entire grammar on the basis of a small set of "generative rules." We should therefore expect to find grammatical features shared by all human languages. Greenberg, on the other hand, painstakingly listed the grammatical features shared by multiple languages, positing that such commonalities must reflect innate cognitive biases. Greenberg's data paid special attention to word order, yielding the hypothesis that some grammatical features of languages must be codependent. Chomsky's view, in turn, predicts that as languages evolve and change, the grammatical features generated by the same rule should covary. A team led by Russell Gray, a New Zealand psychologist, recently released the results of a massive study that they claim casts doubt on these universalist predictions. Borrowing the technique of phylogenetic analysis from evolutionary biology, Gray and his colleagues reconstructed four family trees containing more than two thousand languages. They found that the co-dependencies in word-order change varied among families, suggesting that each family has evolved its own rules. Moreover, if co-dependencies were common to two families, there was evidence that they had separate origins within each family, thus yielding no evidence of family-invariant rules. Many universalists, however, were unimpressed: that languages vary widely is well-known. But given that some language is spoken by virtually all human beings, it would be strange if it did not reflect cognitive universals. It is the search for those universals, not the cataloguing of variations, that should take priority.