Letters to the Editor

LETTERS TO THE EDITOR Dear Sir: Dr. Müller has misrepresented many of my opinions in his review of my broadcast lectures on The Future ofMan; he has a great gift for saying whathe means, but none at all for saying what J mean. Müller concedes that artificial measures like the eradication of malaria may sometimes lead to genetical improvement, not to deterioration; but then he goes on to accuse me ofregarding this as the "typical" case. What I said was that the arguments which treat genetic deterioration as a necessary consequence ofmedical improvement "are serious and respectable, but they are not generally valid; they may sometimes represent the very opposite of the truth." But malaria is a very important case, whedier typical or not; some two and one-halfmillion people are said to die ofmalaria every year. Even in advanced industrial countries we are not more than two or three generationsremoved from populations scourged byinfectious diseases: consider only the bills ofmortality ofNew York City ofthe eighteenforties. Can Müller be sure that inborn resistance to cholera, typhoid, pox, and plague was not also—as with malaria—bought by genetical devices thathave been discredited by the advances ofmedicine andhygiene? Müller seems to me to take a parochial and unhistorical view ofthese problems. Tremendous medical advanceshave already occurred—that is the point—and there is no good evidence that they have led to genetic deterioration. Müller classifies me as a member ofdie "cult" which maintains that the heterozygous state is something laudable in itself. I expressly repudiated this view (p. 115 ofthe book). My argument cannot be condensed into a sentence, but the gist ofit was that a genetical systemenforcing heterozygosity represents a compromise between getting the best out of individuals while maintaining a population versatile enough to cope with hazards that change from time to time and from place to place. A case can be made for saying that a genetical system that attaches great weight to genetic diversity is part ofour heritage, and partoftheheritage ofmostotherfree-livingand outbreeding organisms. Ifthisinterpretation is true, we should adjust our thoughts accordingly, not tryto shout it down. Muller's harping on my alleged championship of mediocrity is unworthy of a great scholar: it sounds like a political speech. The reason why I do not regard the secular decline of intelligence (if it is indeed happening: some geneticists think not) as seriously alarming is because I think that the negative correlation between intelligence and fertility may be a temporary demographic episode. There is moderately good evidence, some ofthe best ofit from America, that the difference betweenthefertilitiesofthe more and theless intelligentis declining. Ifit is, our anxieties may decline proportionately. 585 Muller declares that I regard "cultural" and genetic evolution as mutually exclusive processes, and takes this as evidence of a "deplorable compartmentalism of mind." I thought and said nothing ofthe kind. I said that the two processes are entirely different, as indeed they are; and with the recognition ofthis difference, most ofthe older social Darwinism collapses in ruins. As to "geneticism" (he hates die word; I, what it stands for), Müller knows as well as I do that many geneticistsinthe past, and not onlyin the past, have passed damfooljudgements on a huge variety ofhuman affairs, and have made cocksure predictions which die growth oftheir own science has brought into contempt. One day I shall compile a ghoulish anthology, a kind of genetical horror comic, of the fatuous and sometimes cruel opinions that geneticistshave held abouthow to promote the genetic welfare ofmankind. Muller's name will not appear in this anthology, because, in addition to being one ofthe world'sleading geneticists,he is apassionatehumanistbesides; butinreviewing The Future ofMan he has allowed his passions to cloud his judgement. Let me make it clear that though Irepudiate aheroiceugenicsthatprofesses concernfor mankindin general, forthe species Man, I am strongly in favour of a humane and circumspect eugenic policy that might be described—paraphrasing Karl Popper—as a piecemealgenetical engineering. It is a policy that has die welfare ofhuman beings considered individually as its paramount concern. But obviously I cannot argue the matter here. P. B. Medawar University College London, W.C. ? Dear Sir: The history ofscience amply...