|Turned up to eleven: Fair and Balanced|
Friday, May 31, 2002
"Bulldog" has made some interesting points (by the way, I am more than honored to be Darwin to his Huxley, although I am pretty certain I don't deserve it), so I will try to respond to them in kind.
This is true, as far as it goes. I was probably unwise to say that his statement about a "range of intelligence values" was wrong, but more correctly that it leads to an underestimation of human potential, IMO. The reason I brought up all of this was so I could introduce the notion of signal transduction into this topic (intelligence, "g", genetics and environment, for those keeping score at home). At the level of single-celled organisms, the ones I know best, signal transduction from the sensory proteins on the cell surface is crucial to the bacterium's survival. Bacteria take in signals about their surroundings all the time; they detect chemical gradients, pH, Oxygen, CO2, Nitrogen (in various forms), and in many cases light, and they respond by way of gene expression. Not only is all of this true in larger animals, such as people, but the systems are bound to be more complex, more finely tuned, and "pleiotropic" (that means one stimulus has many effects). So when "Godless" says
I say, yes, but the upper bound may be a lot different from what we think it is, based on the rather crude epidemiological studies that we can currently do.
This reminds me of David Brin's Uplift series, in which human beings, using technology and genetic engineering, "uplift" chimps and dolphins to sentience (i.e., human-like intelligence). It is an intriguing series, that I heartily recommend. The best book in the series is, IMHO, Startide Rising. In any event, I think this argument is a tad too pat, and maybe needs to be explored. While it is true that monkeys probably don't have the brains for DE's (many humans don't either!), we are talking, to some degree about apples and oranges. After all, my (not quite) hypothesis is purportedly that human intelligence is unbounded, but actually, I would be quite satisfied with the notion that all humans could be potentially "stimulated" to very high intelligence, for all practical purposes equivalent. This is not "radical egalitarianism", but simply entertaining the notion, which I think we cannot reject a priori, that the genetic bounds of intelligence are outside, at the high end, the environmental bounds. For example, one might propose the hypothesis that there exist a relatively few different genetic brain types. The normal brain, with a very wide range (but not infinite) of "g" values, the mentally retarded, who might have some specific defect (possible reparable by genetic means, even), genius, a brain with a virtually unique structure, in some way we don't yet understand, that allows for revolutionary insight, and insanity, which is again almost certainly some chemical or physical problem with the brain.
Lets examine an "allelic" model of the brain more closely. Suppose some relatively small number of genes (say, a few hundred), describe the structure of the brain. It seems quite likely to me that of the four brain types listed above, a small number of differences separates the clinically insane from the "normal" from the genius from the retarded. If the brain is like most other complex biological systems (and it probably is, from a molecular standpoint), most of the genes involved are "housekeeping" genes, which simply proscribe a basic structure, that is relatively invariant. Probably, deleterious mutations in some of these genes are what cause certain forms of insanity (schizophrenia, for example, is strongly hereditary). There is likely to be some combination of allelic variations that correspond to severe mental retardation, in various forms, and others that correspond to minor forms such as dyslexia. The bulk of the allelic variation, however, may (or may not) have an effect on "g", and this is where the meat of the question is. I submit, therefore, that genius and retardation be dropped from consideration, for this purpose.
So, where does this leave us? Well, I think, at this point, we have two competing hypotheses. One would be that the allelic variations (which we have no quantitative idea of) play a large role in determining intelligence, and the other is that they do not. The best answer we have (based on heritability studies), is that the influence is about 50/50. Ok, so I still ask the question, to what extent can we use modifications of the environment (and this could include medical treatments), to enhance intelligence? I submit that as we learn more about these phenomena, we will come to the realization that there are specific points in development where certain environmental cues are crucial (they may well be unexpected in nature). I wouldn't be surprised if, when optimized, the intelligence of a population is much more narrowly distributed than currently is the case (note, at this point we have abandoned the distinction between "g" and multiple intelligences; this is not, gentle reader, because I have conceded the argument, but rather because as a shorthand it is more convenient), because environmental disparities between human populations are probably much larger than genetic ones, based on evolutionary rates compared with the history of humanity. This actually goes back to my very original point (who remembers that?), which was that the "races" have not been physically or reproductively separate long enough for the kind of deep, population genetic differences that GC was originally speculating on.
I have not really discussed very much the notion of signal transduction and environmental factors in development in this post, unfortunately, but I am of the opinion that this is actually where the future of "enhancing humanity" lies. It strikes me that genetic enhancement of cognitive ability will be very difficult, since it will likely require the development of a coherent biological theory of consciousness. Even then, we won't be able to enhance humans beyond the limits of our "maximal intelligence gene set", and will be further limited by as yet unknown environmental and developmental factors. Maximizing gain by optimizing the environmental cues for developing children, however, seems to me more promising because we can do non-invasive, quantitative study of these factors, with minimal ethical hurdles (no experiment in this regard would involve hurting a child in any way, but simply providing them different stimuli, such as toys, and different diets, etc, and monitoring their development).
In the end, however, it seems to me that GC and I are differing largely on the structure of the bounded set of intelligence(s), and whether the distribution can be perturbed significantly by conditional changes.
P.S. Don't get into a mathematical argument with this guy, he will run circles (chaotic ones) around you. I am interested in Chaos theory myself (that is to say, I read Gleick's book of the same title), but I wouldn't have come up with that one!