On Being Human — A Reflection

@John_Harshman
Noam Chomsky
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From something I wrote I quote another scientist:

From the materialist point of view our human brains are the product of evolution — an ape-like brain grown larger and more sophisticated. Physically a human brain is three times the size of a chimpanzee brain, and uses considerably more energy. Our brain represents 2 percent of our body weight but uses 20 percent of the oxygen we breathe. However, our brains are not merely enlarged ape brains — there are other differences. Our brains contain neural structures, enhanced wiring, and forms of connectivity among nerve cells not found in any animal.1 Our neurons continue dividing well into adulthood and have a 10-fold higher density than chimps. The human brain is something new, something different, as can be seen by the things we do that animals don’t.

In fact our differences are likely to be greater than our similarities. David Premack, the late psychologist at the University of Pennsylvania said:

In examining claims of similarity between animals and humans, one must ask: What are the dissimilarities? This approach prevents confusing similarity with equivalence. We follow this approach in examining eight cognitive cases — teaching, short-term memory, causal reasoning, planning, deception, transitive inference, theory of mind, and language — and find, in all cases, that similarities between animal and human abilities are small, dissimilarities large. 2

Are the dissimilarities so large as to make Darwinian evolution of our brains and abilities impossible? Our brains have vastly more ability than is needed for survival, most notably the capacity for language and abstract thought. We are orders of magnitude beyond anything animals can do.

Let’s consider language. As a thought experiment, imagine what life required about 500,000 years ago (noting the irony of the experiment as you do so). The people alive then were hunters and gatherers. Their tools were Acheulean hand-axes and sharpened wooden spears. Fire was used for cooking. Listen to David Premack again:

I challenge the reader to reconstruct the scenario that would confer selective fitness on recursiveness. Language evolved, it is conjectured, at a time when humans or protohumans were hunting mastodons…Would it be a great advantage for one of our ancestors squatting alongside the embers, to be able to remark, “Beware of the short beast whose front hoof Bob cracked when, having forgotten his own spear back at camp, he got in a glancing blow with the dull spear he borrowed from Jack”?

Human language is an embarrassment for evolutionary theory because it is vastly more powerful than one can account for in terms of selective fitness. A semantic language with simple mapping rules of a kind one might suppose that the chimpanzee would have, appears to confer all the advantages one normally associates with discussions of mastodon hunting or the like. For discussions of that kind, syntactical classes, structure-dependent rules, recursion and the rest, are overly powerful devices, absurdly so. 3

  1. David Premack, “Human and animal cognition: Continuity and discontinuity,” Proceedings of the National Academy of Sciences, 2007, vol. 104 no. 35, pp 13861–13867.
  2. Premack, ibid.
  3. Premack, D. “‘Gavagai!’ or the future history of the animal language controversy.” Cognition 19: 207-296.
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OK, I suppose two counts as “some”. You must admit that the overwhelming majority of scientists, including the overwhelming majority of those who work in the field of human cognition, don’t consider that gap unbridgeable.

I will also point out that “unbridgeable” and “unbridgeable solely by natural selection” are not the same thing. Why not try theistic evolution on for size? Should solve all your problems.

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That a look at this book. Homo Erectus and then all later human species bridged all of Chomsky gaps and all of the gaps describe by one other scientist you reference from 2007. This book is on the latest discoveries on human language.

https://www.amazon.com/How-Language-Began-Humanitys-Invention/dp/0871407957

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Yes, the advancement of human language is based more on advancing culture, human creativity, and human innovation than by natural selection.

@John_Harshman
Here is a blockbuster. Look at the authors, then read the abstract. Scorched earth. They do offer some suggestions at the end.
https://www.frontiersin.org/articles/10.3389/fpsyg.2014.00401/full

That’s an unsettling display of triumphalism about what we don’t know. Ignorance is strength?

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“Science can’t give us all the details therefore GAWDDIDIT”. That’s been ID’s only argument since Day 1.

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@Timothy_Horton I didn’t say anything about God. I was pointing to scientists ( some big ones!) who say we have gaps in our evidence for language evolution. Lots of theory. Little to no evidence. Nothing about gaps.

Please don’t put words in my mouth.

Likewise @John_Harshman I was answering your question. When I called it a blockbuster it was in reference to the tone of the paper itself, and the same for scorched earth. There have of course been indignant responses in the literature. My only intent was to show that there are scientists not convinced there is a path or that we have found evidence for an evolutionary path to language.

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Those are two different things, you know. And “unbridgeable” is a third.

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Which of these have been demonstrated to be unbridgeable?

We are animals, so what we can do animals can do. Also, you have not shown that our intelligence is not needed for our survival. You have merely asserted it.

Our current level of intelligence was needed for those tasks.

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Not knowing how specific human attributes evolved is not the same as saying they couldn’t evolve. Surely you understand the difference.

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I didn’t say you did. I didn’t quote you. I wasn’t even responding to you, just making a general observation about how ID operates. My apologies for bumping that chip on your shoulder.

But since you’re here, do you agree there’s no scientific evidence for a supernatural origin of human language capabilities?

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This is one of the grand mysteries of human origins. We don’t have strong evidence one way or another. It is in fact a singular event in history, even if it arose among a population of our ancestors. Who could really know if God was involved or not?

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“We don’t know” doesn’t infer or imply “a supernatural entity did it”. I’m sure you realize that.

Science rejected all “God of the Gaps” arguments as useless three centuries ago, and for good reason.

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Of course I realize this. Explaining ignorance makes space for different ways of thinking about it, without adjudicating which one is correct.

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That question applies to all of science, not just to human evolution. What we could do is understand the genetics of human evolution, and determine if those changes are consistent with the processes we observe in the world around us. That seems to be consistent with how @agauger approaches the problem, given the experiments she has proposed in the past.

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@T_aquaticus
Yes. If I understand you correctly.

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On being human … as if we had any other choice??? :wink:

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@T_aquaticus

I think it’s important to understand what is meant by “unbridgeable.” It doesn’t mean, “we’re throwing up our hands, the transition to “human” is too fast and so God had to intervene.” Things could have been accomplished through purely natural processes with a saltational jump. Chomsky definitely isn’t thinking of divine intervention. For him, I’m pretty sure language came about through a random mutation.

Surely our intelligence, etc. was advantageous in the evolutionary process but it isn’t clear to me why the talent of a Bach, or Shakespeare or Einstein or (personally) David Gilmour or John Petrucci should exist IF evolution is primarily about adaptation. Does it not seem that consciousness is what evolution is ultimately heading towards, and in the case of humans (and dolphins, octopuses and apes to a lesser degree) an exceptionally gifted consciousness? This could have been accomplished through an entirely natural process, but the philosophical question of WHY DID IT HAPPEN THIS WAY seems to present itself.

I’m curious what you think of Plantinga’s evolutionary argument against naturalism. Or Thomas Nagel’s work.

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No. Evolution doesn’t seem to be heading toward anything. That you suppose so is an artifact of you being at the end of a long lineage, while you ignore the rest of the tree as just “side branches”. Consider that most life is single-celled, and only a few twigs have gone past that. A good number of multicellular species have no brains at all; I’d say “most species” if not for insects. And most brains are tiny, the organisms that have them being without anything we would call “consciousness”.

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