Jun 20, 2022Liked by Sarah Constantin

I had trouble parsing part of this, so let me rewrite it in my own words:

There used to be a question of why there was 100ky of "anatomically modern humans" before there were "behaviorally modern humans." Recently, the evidence of behavioral modernity has been pushed back, so there no longer is a gap in time between anatomical modernity and behavioral modernity. But this gap was only the tip of the iceberg. It was a tidy way of talking about the mystery, but removing it doesn't remove the actual mystery; comparing anatomical modernity and behavioral modernity is a category error, because anatomical modernity is an endpoint, whereas behavioral modernity is a starting point. The brains got larger for millions of years, leveling off 150kyo, and then behavioral change accelerated, lots of new behavior starting then. But if the big brains lead to the modern behavior, why didn't the behavior accumulate for millions of years? This is the real mystery and moving modern behavior back 100k more years doesn't help address it.

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I'm surprised that you have not even mentioned language, something which took evolution of the jaw, tongue, throat as well as brain and which would have revolutionized hominid culture. Have you read Julian Jaynes "The Origin of Consciousness in the Breakdown of the Bicameral Mind". I don't know if I believe Jaynes, but he made the importance of language clear to me.

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If AMHs are genetically identical with BMHs, I think the only reason why there is an intelligence gap is that there was some 'software upgrade' among the ancient humans, approx. 40k-60k years ago, roughly the time when humans landed in Australia. It was more of a cultural thing, instead of a physical/genetical thing. To be more specific, it can only be caused by the evolution of LANGUAGE. If we could have a chance to turn our lens a bit closer, it was very probable that the ancient language was way different than the more modern ones (from 40k-60 years ago afterwards). For example, can we really imagine a language without the pronoun 'I' (to symbolize 'self'), or a language without the concept of 'therefore' (to symbolize logical causality)? If that was possible, then the evolution of intelligence after the emergence of AMH can be taken as something like Operating System upgrade (We are now all very familiar with this, experiencing the automatic OS upgrade pushing from Big Tech companies like Apple/Microsoft), instead of CPU upgrade.

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I appreciated these thoughts. I was struck by this: "If humans 'got smart' through some kind of feedback loop where sophisticated behaviors drove greater evolutionary or cultural selection for ever more sophisticated behaviors . . ."

I wonder whether it's necessary to link a feedback loop with selection at all. I'm thinking of the extended concept of mind in approaches related to embodied cognitive science, where "thinking" (both reflective and in the form of purposive action) is a dynamic between the brain and the environment in which it is living and acting. In those models, changes in the environment and changes in thinking are complementary, and restructuring the environment will, over time, restructure thinking--all independent of issues of genetic evolution and selection. As the social group inscribes more and more of its "thinking" in the lived social world, its actors' minds (not brains) are modified and make their own modifications in an incrementally new way. A feedback loop.

There was an ancient Chinese thinker named Xunzi who developed such a theory of human social evolution (although his version envisioned the initial structures of the social environment as being devised by a small number of sages who gained political power). His basic notion was that humans are distinct as a species primarily in their ability to formalize norms of behavior and inscribe their surroundings in ways that create a dynamic of constantly evolving cultural, technological, and economic institutions. "The human mind molds things not of its species to nurture its species," the term for 'nurturance' implying dynamic growth, not simply static sustenance. (Sorry for the intrusion of this theme, it just seemed such a neat parallel with the 'feedback loop' model.)

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'The evolution and prehistory of Homo sapiens and its ancestors seems to weakly point against the “single discrete origin point for human intelligence” hypothesis.'

That must be the understatement of the entire article! Human uniqueness lies in the invention and use of complex tools, which depends on an integrated interplay of brain, hands (i.e. bipedalism), vocalisation (language) and socialisation. Clearly, this requires biological and cultural co-evolution, with a positive feedback loop creating a rapidly accelerating "upward spiral" (over perhaps hundreds of millennia, but still only a blink in geological time). Imagine the genetic mutations underlying all the necessary CNS re-wiring, and subtle distal anatomical changes!

Tool-making requires a concept of problem and solution, of before and after, of distant pasts and futures, of purposes and goals, i.e. teleologism -- and this underlies religious belief, an inevitable feature of all known human societies. If the rest of the world is here for our use and benefit, then we must also be here for someone else's purposes: QED. (I don't happen to believe that, but I can fully understand why many other people might.

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My knowledge of human history pre-civilisation is very sparse but I see development like this:

1. Hominids start using tools. ~1 million years ago

2. Homo Sapiens start using much more sophisticated tools. ~100,000 years ago

3. Agriculture. ~10,000 years ago

4. Philosophy. ~2,500 years ago

5. Industrialisation. ~250 years ago

For these last three "great leaps forward" there was no significant change in humans genetically and yet there were huge gaps in time between them. It probably just takes a long time to consolidate past gains, then wait for the right conditions, before a new spark is struck.

The last significant genetic change likely happened between steps 1 and 2. I imagine looking at knapping provides the key, why did it take so long for improvements there (100 generations of knapping the exact same way?).

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Thought capabilities were provided by space aliens, deciding to accelerate complexity of life to see how long it would take for the constructs to self-destruct.

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Surely the development of complex speech must be an important factor. This enables cooperative action, social history, teaching of skills etc.. Thiswould have been a great evolutionary advantage.

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