人类语言的迅速崛起

At some point, probably 50,000 to 100,000 years ago, humans began talking to one another in a uniquely complex form. It is easy to imagine this epochal change as cavemen grunting¹, or hunter-gatherers mumbling² and pointing. But in a new paper, an MIT linguist³ contends that human language likely developed quite rapidly into a sophisticated system: Instead of mumbles⁴ and grunts⁵, people deployed⁶ syntax and structures resembling the ones we use today. "The hierarchical complexity⁷ found in present-day language is likely to have been present in human language since its emergence," says Shigeru Miyagawa, Professor of Linguistics⁹ and the Kochi Prefecture-John Manjiro Professor in Japanese Language and Culture at MIT, and a co-author of the new paper on the subject.   To be clear, this is not a universally accepted claim: Many scholars believe that humans first started using a kind of "proto-language" -- a rudimentary, primitive¹⁰ kind of communication with only a gradual development of words and syntax. But Miyagawa thinks this is not the case. Single words, he believes, bear traces of syntax showing that they must be descended¹¹ from an older, syntax-laden system, rather than from simple, primal¹² utterances¹³.   "Since we can find syntax within words, there is no reason to consider them as 'linguistic⁸ fossils' of a prior, presyntax stage," Miyagawa adds.   Miyagawa has an alternate hypothesis about what created human language: Humans alone, as he has asserted in papers published in recent years, have combined an "expressive¹⁴" layer of language, as seen in birdsong, with a "lexical" layer, as seen in monkeys who utter isolated¹⁵ sounds with real-world meaning, such as alarm calls. Miyagawa's "integration¹⁶ hypothesis" holds that whatever first caused them, these layers of language blended quickly and successfully.