“human neural uniformity” is not “liberal creationism”

Daniel Dennett says somewhere or other that the weak points in an argument are frequently betrayed by the appearance of rhetorical questions, and IME this heuristic has considerable value. One not-quite-an-argument popular among biological racists is expressions of flat incredulity – sometimes in the form of rhetorical questions, sometimes in charges of “liberal creationism” or “evolution stopping below the neck” – towards natural selection resulting in native intellectual equality, or, to use the preferred racist term, “human neural uniformity.”¹ To interpret the claim charitably, it would be that native intellectual dissimilarity – and, particularly, human native intellectual dissimilarity across regional groups – is an antiprediction. Would it not be an extraordinary coincidence for natural selection, that most unforgivingly Tigerest of Mothers, to install the same abilities in everyone everywhere, when the tradeoffs between intelligence (or whatever else is under discussion) and other adaptive goods must surely (except by extraordinary coincidence) vary by climate and social structure? Does HNU not rest on the razor’s edge of probability?

There are two essential points to be made here.

The first, and more trivial, is to distinguish between exact and approximate equality. The “razor’s edge” objection applies to any exact claim about the position of a continuous variable, 15 as much as 0. Far be it from me to dismiss a good anti-racist argument when we can find it, but “blacks are naturally one standard deviation stupider than whites” is just not usefully answered by jeering at the extraordinary prior improbability of a precise difference of one standard deviation: it could, for all that is possible at this level of abstraction, be close enough to one standard deviation to make no difference. So too with zero – things can be close enough to make no difference, or for none to make a credible claim to superiority. Hobbes was a vain enough man to think himself quite smart, but he was also quite smart enough to be reflective about his vanity, when he wrote, in defense of human equality for all practical purposes, that:

NATURE hath made men so equal in the faculties of body and mind as that, though there be found one man sometimes manifestly stronger in body or of quicker mind than another, yet when all is reckoned together the difference between man and man is not so considerable as that one man can thereupon claim to himself any benefit to which another may not pretend as well as he. For as to the strength of body, the weakest has strength enough to kill the strongest, either by secret machination or by confederacy with others that are in the same danger with himself.

 

And as to the faculties of the mind, setting aside the arts grounded upon words, and especially that skill of proceeding upon general and infallible rules, called science, which very few have and but in few things, as being not a native faculty born with us, nor attained, as prudence, while we look after somewhat else, I find yet a greater equality amongst men than that of strength. For prudence is but experience, which equal time equally bestows on all men in those things they equally apply themselves unto. That which may perhaps make such equality incredible is but a vain conceit of one’s own wisdom, which almost all men think they have in a greater degree than the vulgar; that is, than all men but themselves, and a few others, whom by fame, or for concurring with themselves, they approve. For such is the nature of men that howsoever they may acknowledge many others to be more witty, or more eloquent or more learned, yet they will hardly believe there be many so wise as themselves; for they see their own wit at hand, and other men’s at a distance. But this proveth rather that men are in that point equal, than unequal. For there is not ordinarily a greater sign of the equal distribution of anything than that every man is contented with his share.²

But more importantly: it is by no means impossible or even wildly improbable for a population to end up with functionally identical intelligence (or whatever³) even when migration across heterogenous environments imposes different fitness conversion rates between it and other traits. All you need is – and I will be terribly unscientific here and introduce an element of unfalsifiability by saying nothing makes this the only logically possible scenario leading to this outcome; it is but a just-so story – those tradeoffs to be gimmes at all points available within chassis limitations.

If physicalism is correct, strong AI must be possible, and it is fairly certain that there are hardware layouts upon which would supervene minds vastly superior to our own, and perhaps, some day, we shall devise them. But evolution only ever seeks out local optima. This makes it vastly inferior to human design; every transitional form must pay off in terms of fitness (under whatever environmental conditions it appears;) it knows irrationalities plenty but no speculative bubbles. What if intelligence is subject to such chassis limitations – if the human brain is about as advanced along that dimension as can be given its design constraints? Several considerations make this plausible.

First, there does not appear to be much low-hanging chemical fruit available for improvements to intelligence. There haven’t been any conspicuously successful nootropics other than caffeine (which shifts cognitive capacity around in time; the piper must yet be paid,) and large-scale studies have consistently failed to find SNPs that impact intelligence. (Recent reports of the KL-VS gene observably impacting intelligence have been making a splash, but the reaction among even the hereditarians I know is one of skepticism.) Obviously, I would be happy to be proven wrong on this point – low-hanging fruit are a good thing, after all! But they appear to be rare at best – aside from the correction of dietary deficiencies, removal of toxins, &c. (Likewise, while genes associated with superior intelligence are inglamorous or tentative at best, we have identified genetic correlates of mental retardation.)

Second, intelligence is likely the result of an intra-human arms race, rather than struggle with the extra-human environment. Humans have intelligence enough to kick the ass of (non-human) nature ten times over everywhere on the planet – the myth of the noble savage, living in harmony with her natural environment, is exactly that – but we do have a tendency to get into more nettlesome battles of wits with each other. This means that the fitness benefits of intelligence are internally driven, and are monotonically useful. Of course there may be a point where further advances become prohibitively expensive – but that point may well be past the point imposed by fundamental design limitations.

Third, humans have unusually low genetic variation; we are a bottleneck species. This point has been emphasized in previous anti-racist arguments; the point here is not just that absolute current variation is comparatively low, but that there is less room for maneuver.

This is, of course, not a general argument for “HNU,” nor is it meant to be – only a refutation of a particular enthymeme. Cde Krul has more general treatments of the subject here and here.

f.n.

  1. The term, taken literally, would of course imply that humans all have the same memories, current mood and thoughts, and so on. This elision between neurology and genetics in hereditarian rhetoric is of course purposeful if not necessarily deliberate – neural determinism flows almost directly from metaphysical materialism, while genetic determinism is considerably less trivial – and makes up much of what Cordelia Fine has justly called “neurosexism.”
  2. Thos. Hobbes, Leviathan, ch. 13
  3. I think the relevant trait under selection here is actually something like “social intelligence,” which implies things like social programmability and weird things like rituality. Randal Collins’ Interaction Ritual Chains convinced me that a parsimonious view of human nature is actually quite plausible, and something like strong selection for the trait in question explains why we end up with miniscule, rather than massive, modularity.
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11 Responses to “human neural uniformity” is not “liberal creationism”

  1. Multiheaded says:

    Whoa.

  2. nydwracu says:

    Second, intelligence is likely the result of an intra-human arms race, rather than struggle with the extra-human environment.

    The environmental arguments I’ve seen (cold winters, mostly) were really about time-preference.

    On the one hand, that means I haven’t seen environmental arguments for IQ differences, unless time-preference is correlated with IQ. (Which doesn’t seem improbable, but I don’t know.) On the other hand, if time-preference is relevant and has non-negligible genetic determination…

    • Matthias says:

      I agree that that subpoint works better for IQ (or the like) than time preferences. (My almost-fully generalizable counterargument here is that trainable time preferences, which opens up as a possibility once you have our kind of brain complexity, are generically superior to fixed ones. But that’s a nontrivial claim (I can anticipate a few objections) and its own discussion.)

    • satt says:

      The environmental arguments I’ve seen (cold winters, mostly) were really about time-preference.On the one hand, that means I haven’t seen environmental arguments for IQ differences, unless time-preference is correlated with IQ.

      Cold winters arguments for racial IQ differences have been put forward by the hereditarian academics Richard Lynn

      The theory I have advanced to explain these race differences in IQ is that when early humans migrated from Africa into Eurasia they encountered the difficulty of survival during cold winters. This problem was especially severe during the ice ages. Plant foods were not available for much of the year and survival required the hunting and dismembering of large animals for food and the ability to make tools, weapons and clothing, to build shelters and make fires. These problems required higher intelligence and exerted selection pressure for enhanced intelligence, particularly on the Orientals.

      and J. P. Rushton

      The climate differences influenced mental abilities. In Africa, food and warmth were available all year round. As Homo sapiens moved out of Africa they faced an entirely new problem — cold winters. Gathering and storing food, providing shelter, making clothes, and raising children during these long winters were more mentally demanding tasks than those that humans had faced previously. These tasks called for larger brains and slower rates of growth.

      • satt says:

        Huh, seems you shouldn’t use paragraph tags in a blockquote. Where I quote nydwracu there should be a paragraph break before “On the one hand”.

  3. Pingback: notes on Peart & Levy’s “Vanity of the Philosopher” | Vulgar Material

  4. Douglas Knight says:

    Your third point doesn’t make sense to me. Absolute diversity does not seem to me relevant to a relative claim that measures inter-racial differences on the internal scale of the standard deviation.

    • Matthias says:

      The argument here isn’t just that lower absolute genetic variation should imply lower absolute phenotypic variation, but that low absolute genetic variation implies less room for maneuver. If you imagine a hill in a fitness landscape with individuals distributed about the acme, a more tightly distributed cluster is less likely to overlap with an alternate hill.

      • Douglas Knight says:

        What are these hills? IQ 100 and IQ 85? Those hills are one standard deviation apart, the same size as the crowd. Asserting that everything is small doesn’t change that fact.

        Maybe humans don’t have enough diversity to move 30 standard deviations, which is typically achievable by selective breeding. But 1 standard deviation is just the size of the crowd, so such movement is always possible.

  5. Wulfrickson says:

    Ashley Montagu makes a similar argument to your second point, “intelligence is likely the result of an intra-human arms race,” in the introduction to his book Race and IQ. The part I’m referring to is visible in the Google Books preview (starting on page 8). Just to quote some (apologies for the long quote, but it’s all good):

    Certainly the brain has undergone considerable evolutionary change, but the pressures of natural selection have not acted directly on the brain but indirectly through its functions, especially capacities for its culturally acquired functions. The complexity and size of the human brain represent the end-effects of the action of selection on the functions of human behavior in human environments. What has been under selective pressure is not the brain as an organ, but the skill in using it and its competence in responding as a culturally adaptive organ,

    Contrary to Jensen, there is every reason why the brain should be exempt from his generalization [that there are substantial racial differences in biology and physiology]. […] As Professor George Gaylord Simpson later independently put it, “There are biological reasons why significant racial differences in intelligence, which have not been found, would not be expected. In a polytypic species, races adapt to differing local conditions but the species as a whole evolves adaptations advantageous to all races, and spreading among them all under the influence of natural selection and by means of interbreeding. When human races were evolving it is certain that increase in mental ability was advantageous to all of them. It would, then, have tended over the generations to have spread among all of them in approximately equal degrees. They would, in fact, have to become distinct species; but human races are all interlocking parts of one species.” And as the geneticists Paul David and L. H. Snyder have written, “flexibility of behavioral adjustment to different situations is likely to have had a selective advantage over any tendency toward stereotyped reactions. For it is difficult to conceive of any human social organization in which plasticity of response, as reflected by ability to profit from experience (that is, by intelligence) and by emotional and temperamental resilience, would not be at a premium and therefore favored by natural selection. It therefore seems to us highly improbable that any significant genetic differentiation in respect to particular response patterns, populations or races has occurred in the history of evolution.” “To assert the biological unity of mankind,” write Professors Sherwood L. Washburn and C. S. Lancaster, “is to affirm the importance of the hunting way of life. It is to claim that however such conditions and customs may have varied locally, the main selection pressures that forged the species were the same.”

    […]

    The important fact that Professor Jensen fails to understand is that while physical environments may have differed in the extreme, the conditions of selection under which man’s mental evolution occurred were everywhere alike. The cultural differences between a Congo Pygmy and an Eskimo of the Far North are only superficially different. If you live in the Congo you need neither clothes nor sleds; if you live in the Far North you need both. There are great differences in detail between the foodgathering-hunting cultures, but in the responses they have made to their particular environments they are strikingly and fundamentally alike. They are alike in their material culture, in their social organization, in the absence of chieftains, political or state organization, permanent councils, belief in gods, warfare, and the like.

    Again, this is a theoretical rebuttal to a theoretical argument: it doesn’t work by itself as a rebuttal to, say, particular sets of IQ data showing racial differences, but it’s a good response to the usual argument from incredulity.

    • Matthias says:

      Gracias, but also, sorry for taking so long to approve this! I took a hiatus from writing for a while and since then have accumulated hundreds and hundreds of spam comments, so glad there was at least one substantive one in there.

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