There has been a lot of talk in recent years about the intellectual and linguistic capacities of Neanderthals. This brief overview published last year in the research news section of the website of the Max Planck Institute reflects the currently popular view that their capacities were more or less equivalent to ours.
More controversial is the claim that the origins of modern language date not from about fifty or a hundred thousand years ago but from about one million years ago, "somewhere between the origins of our genus, Homo, some 1.8 million years ago and the emergence of Homo heidelbergensis." [Homo heidelbergensis is thought to represent our most recent common ancestor with Neanderthals, the split occurring about 500,000 years ago.]
More controversial still are claims being made by researchers at the Institute – and publicized in a recent New Scientist article [paywall] which is big on speculation but largely devoid of substantive content – that the cultural interactions between modern humans and their Neanderthal cousins included linguistic exchanges which left discernible traces in the syntax of non-African languages. Possible subtle structural differences between African and non-African languages coupled with detailed computer simulations of language spread would supposedly reveal something about the structural properties of hypothetical Neanderthal languages (which hypothetically impacted on non-African languages only). This is drawing a very long bow.
In a few days I will post some notes and reflections on some broader questions about early humans and the prospects for making progress in understanding their cultures and the nature of their languages.