An interesting piece from Joseph Heath that compares the opposed theories on the origins of human intelligence posited by Yuval Noah Harari and Joseph Henrich:
What makes the field of human evolutionary theory so interesting right now is that, deep down, we really don’t know how any of these capabilities evolved. At some level they must have been adaptive, but nobody really understands specifically why or how any of it was adaptive. On the other hand, we know a great deal about how it could not have evolved, because so many bad theories have been proposed over the years, which have not stood up to careful scrutiny. Typically they start out as speculative theories, until someone comes along and says “show me a model of how that could have evolved,” and someone takes the bait, starts building a model… and then realizes that it couldn’t have evolved that way. Indeed, it has turned out to be so difficult to produce an evolutionary model that could plausibly explain any the items on the above list that formal modeling has been where the most interesting action has occurred over the past several decades of research.
Harari’s model proposes the sequence of development working like this:
intelligence → language → cooperation → culture
Humans first evolved intelligence levels capable of then developing complex language. Then social cooperation and development of culture flowed from these changes.
Henrich inverted the timeline:
culture → cooperation → language → intelligence
In his view, blind mimicry led to complex cultural behavior — think of how a child merely mimics behavior in its vicinity, without explanation or understanding of why. This tendency of humans to mimic one anothers’ actions without understanding eventually led to cooperative behavior. Then as cooperation improved and became more advanced, more efficient means of rich communication developed to improve cooperative outcomes.
It’s fitting to me that someone with the technocratic, utopian worldview of Harari would begin from the position of intelligence-first: “we became really smart, then started doing amazing things.” His priors in other domains seem to be oriented toward the progressive “anything can be engineered” mindset. So it’s understandable how he arrived at his model.
I read Henrich as more of a “human nature is complicated” guy. So his inversion is also understandable. An immensely complex series of events over a long period of time led to the complexification of human intelligence.