Rocks! But wait, there’s more: the technology heralded by these Acheulean hand-axes that you see (noted for their pear and oval shapes) signify not just the very cutting-edge (groan) way to cut into bone developed between 2 and 1.6 million years ago, but also, the formation of human language and maybe even the genesis of abstract thought.
This is a very big claim, advanced by linguist Derek Bickerton, who studies language evolution and the genesis of pidgin communication. It’s not possible to get direct evidence for the creation of language or abstract thought, of course, because neither are made of matter, but the questions are so important that evolutionary anthropologists have considered them for hundreds of years.
Bickerton’s argument (the super trimmed-down version) is that this type of axe coincided with #1: the appearance of tooth marks which were superimposed with cutting tool indentations on large megafauna that predominated across the planet at that time, and #2: (he argues) a switch in human scavenging from the marrow and refuse remains of these animals in a small territory over to large-distance scavenging to target animal prey. This speaks to a time when environmental changes in Africa created new conditions that would have favored the humans (Homo erectus, specifically) who could have cooperated in hunting, and who could have pivoted from small- to larger- group involvement depending on conditions.
The new behaviors would have favored the use of human language — generalized nouns and verbs that expiated our ancestors’ success in their new lifestyles.
Only *after* language, argues Bickerton, could abstract thought develop. We humans had the genetic predisposition, but language drove natural selection to favor brains whose capacity for it was a major trait.
Bickerton’s arguments are radical among linguists, who manifest their own abstract Acheulean hand-axes in verbal combat fighting about the origin of language.
(*Among other things, Bickerton takes on Chomsky and his idea that the human brain is innately hardwired for grammar without behavior change*)
But, you may ask yourself, didn’t humanity experience a much greater change with the development of complex culture by Homo sapiens sapiens about 50,000 years ago? Where does language fit into that? Bickerton argues that between the genesis of language/complex thought and complex human culture there was a general stagnation of language — for 1.5 million years it was more like pidgin where words were strung together like beads and more nuanced hierarchical language didn’t exist. He posits that H sapiens competing with H neanderthal might have changed things there. I wonder — if this is the case, did humans then experience a shift in their mental abilities analogous to Bickerton’s ideas about the initial development of language bringing about abstract thought? If we speak with more nuance, does our ability to think abstractly then increase?
Sources: Especially page 220, but the whole book _Adam’s Tongue: how humans made language, how language made humans, Derek Bickerton, Hill and Wang, New York, 2009