  This brings us to the question of language evolution: if knowledge of language (say, of the principles of UG) really is inborn in the human language faculty, how did such inborn knowledge evolve? For many  years, Chomsky himself refused to speculate about this matter,  stating that “[e]volutionary theory…has little to say,  as of now, about questions of this nature” (1988:167). Other  theorists have not been so reticent, and a large literature has grown up in which the selective advantages of having a language are  adumbrated. It's good for communicating with, for instance, when  trying to figure out what conspecifics are up to (Pinker and Bloom,  1990; Dunbar 1996). It's a mechanism of group cohesion, analogous to primate grooming (Dunbar 1996). It's a non-genetic mechanism of  phenotypical plasticity, allowing organisms to adapt to their  environment in non-evolutionary time (Brandon and Hornstein 1986;  Sterelny 2003). It's a mechanism by which we can bend others to our  will (Dawkins and Krebs 1979; Catania 1990), or make social  contracts (Skyrms 1996). Language makes us smarter, perhaps by being internalized and functioning as a ‘language of thought’  (Bickerton 1995, 2000). And so on.