Just How Long Ago Did Adam Eat that Apple?

In thinking about how language might have begun, one of the tempting details of the human vocal system has been the “laryngeal descent.” The larynx (aka, the voice box or the “Adam’s apple”) moved a bit down the throat. This anatomical detail was long thought to be exclusive to humans and was also believed to be important in producing certain acoustic distinctions between vowels, so that English speakers can say poke or puke without causing confusion. As the descent appears to have been only 200,000 years old, it seemed that the descent might have had something to do with the introduction of speech, which many people believe to be at most 200,000 years old. Put crudely, the hypothesis said that the human cognitive features needed to support language developed first, but speech only appeared after the laryngeal descent.

This hypothesis supported the Chomsky school of linguistics which asserts that language first emerged as a tool for supporting thinking and only later interfaced with the ability  to vocalize and engage in speech.

It has been known for some  time now that the laryngeal descent is not found only in humans. A report in the latest Science magazine—"Which way to the dawn of speech?” by Jean-Louis Boë et al—reviews the work on laryngeal descent and determined that the previously accepted date for the descent was a bit late. In fact, the paper claims that the trait belongs to many apes, is not essential for making vowel distinctions, and has been part of the human ancestral lineage for at least 20 million years. The surviving great apes all share much of that lineage with us, thus falsifying the conjecture that the laryngeal descent was one of the last steps in evolving speech.

Boë et al go on to ask, “While speech had been thought of as an enabling communication of already developed linguistic cognition, should it now be thought of as an early driver of linguistic cognitive development?” This blog has never expressed the process in quite that way, but it has long supported the notion that vocalizations led to words which led to phrases and, ultimately, to modern language. This latest report does not prove the point, but at least it removes some theoretical obstacles to accepting this blog’s position.