Eugenics
Eugenics
Present problems and applications
Theoretical aspects of eugenics
Eugenics is an applied science that seeks to maintain or to improve the genetic potentialities of the human species. In practice, eugenics is concerned with any qualities that parents confer on their children, because genetic and cultural traits are often correlated or indistinguishable, and because measures that improve one at the expense of the other are to be avoided. Genetics provides the core of eugenic theory, while any implementation must be broadly based on demography, medicine, psychology, and sociology.
Founded by Sir Francis Galton at the end of the nineteenth century, before the rediscovery of Gregor Mendel’s laws of heredity, the early eugenics movement had an insecure scientific foundation and soon became contaminated with class and race prejudice. In the first half of the twentieth century, eugenics was challenged by the growth of equalitarian sentiments and suffered especially from the demonstration of perverted eugenics in Nazi Germany. Since mid-century, the movement has gained respectability by repudiating its early errors and by assimilating scientific advances.
False concepts are still widely propounded in the name of eugenics, and there is disagreement even among geneticists as to the desirability and the urgency of eugenic measures. While some deterioration of hereditary capacities is sure to result from preservation of physically or mentally handicapped persons and from increased irradiation of the population, the rate of this deterioration may be exceedingly slow. Furthermore, medical procedures that ameliorate genetic handicaps do not usually restore complete physical and social normality, so that natural selection still operates against the defects. Although intelligent parents have in the recent past tended to have fewer children than the less intelligent, early predictions of declining general intelligence have not been borne out. Analysis of present trends in reproduction indicates that the increased use and effectiveness of contraception may reverse this fertility difference (Osborn 1963a; 1963b).
The case for eugenics. Three lines of reasoning support the case for eugenics. First, individual families can be spared suffering and disruption if severe hereditary defects are identified and the parents given medical advice or assistance in preventing further births.
Second, the high correlation between parents and children in mental characteristics has some of the same implications whether attributed mainly to heredity or mainly to cultural transmission. Mentally handicapped persons, whose children stand the greatest risk of mental handicap, should at least be assisted if they wish to limit their offspring. More intelligent parents who can provide healthy home environments should be encouraged to bear as many children as they can support.
Third, even a very small improvement in the intelligence of a large civilized population may be expected to increase available leadership significantly. The argument for eugenics does not depend on proving that present trends are downward but on evidence that in important respects the population would be better off with eugenic measures than without them (Shapiro 1959). The only assurance against genetic deterioration is demonstrable genetic improvement.
Modern governments and institutions cannot avoid taking action in the sphere of eugenics. Every large-scale social or economic measure alters the distribution of births among segments of the population, and this distribution determines the genetic potentials of the next generation.
Present problems and applications
Radiation effects. In the past two decades public attention has been focused on possible genetic effects of radiation, namely, gene mutations. Children born to survivors of the atomic bombs in Japan have not shown significant genetic effects, and this supports the belief that to date the deleterious effects of atomic bursts on human heredity are small in comparison with natural mutations already accumulated in concealed form. Yet in absolute numbers, the new induced mutations are probably numerous and destined to take a proportionate toll in death and suffering spread over many generations.
In medically advanced countries the population receives radiation from medical X rays that may greatly exceed the present dosage from fall-out of atomic tests. The debt incurred for future generations by use of X rays or atomic testing must be weighed against the supposed immediate gains in health or national security. Some drugs also induce mutations, and these may need to be controlled in the future. Among the consequences of induced mutations, it is likely that physical defects would be less of a threat to man’s survival under civilization than innumerable small mental impairments.
Race mixture. There is a broad consensus among geneticists that race mixture in man is no eugenic hazard. In plants and animals, the crossing of races may have unpredictable results. Especially if the parent populations were closely inbred, the new generation may show “hybrid vigor”; some other hybrids may show serious disharmonies. In the case of man there is little evidence for either hybrid vigor or hybrid disharmony, and if they occur they are overshadowed by social and cultural phenomena (Chung & Morton 1961). If some small hybrid populations appear to be genetically and culturally inferior to surrounding peoples, this may be due to isolation, inbreeding, or the quality of people who originate or who join such groups. Gene frequencies are not altered by race crossing but only by mutations and selection.
Population policies. The immediate problem of curbing world population growth overshadows problems of population quality. Nevertheless, population policies adopted now are likely to exert qualitative effects for a long time in the future, and these effects should be weighed.
Birth rate differences between educational classes or between occupations appear in most civilized countries to be unfavorable to social and genetic progress. Eugenically sound population policies would therefore reduce or reverse these differentials at the same time that they accomplish their main purpose. A program to reduce births might, for example, facilitate voluntary family limitation and at the same time extend and advertise the economic benefits of such limitation to the more fertile and less secure economic classes. A program to increase births might best achieve this by assisting with higher education and other goals that deter reproduction by persons of high ability.
Genetic counseling. Genetic factors undoubtedly play some role in nearly all diseases and abnormalities, but avoidance of reproduction is genetically indicated only in conditions for which the risk is known to be high. Even in these instances the advisability of reproduction depends on the nature of the disease, on other genetic variables, on socio-economic circumstances, and above all on the parents’ willingness to sustain the risk. People who avoid childbearing for fear of hereditary defects sometimes have negligible genetic risks and are potentially superior parents. Yet those who seek genetic advice often fail to make use of it. Many universities now have centers for genetic counseling, but hereditary diseases will remain unchecked until family planning becomes general and effective. Whether it will ever be possible to transform harmful genes to the normal form by artificial means is a subject of speculation (Hotchkiss 1965).
Theoretical aspects of eugenics
Heredity and behavior. Gallon believed that human behavior could be improved by genetic as well as by cultural progress (1883). Is there today any secure basis for such a belief? On theoretical grounds, the answer to this question is clearly yes. Over the past million years man’s forebears made rapid genetic progress with respect to intelligence and social behavior. The only known mechanism of genetic progress is natural or artificial selection of favorable variations, and selection produces permanent gains only if the selected variations are hereditary. Therefore, hereditary variation must have existed as long as mental capacities were evolving, and there is no theoretical reason to suppose that it has now disappeared. Such hereditary variation in behavior provides the necessary basis for further genetic improvement.
Many psychologists and geneticists have adduced what they regard as evidence for hereditary psychological differences. The most important variation seems to be that between individuals, whereas the observed differences between races and social classes are mainly cultural in origin. Even the concept of good and bad “family stock” is erroneous; both good and bad may occur in any family, and psychological traits shared with grandchildren or cousins must be attributed in large part to common environmental factors or to assortative (selective) mating.
Natural selection. Natural selection is the only known guiding influence in organic evolution and is a necessary correlate of reproduction in a genetically variable organism. Individuals who contribute more progeny than others to the next generation have, by definition, greater biological fitness. So far as the differences in fitness may be hereditary and the environment stable, the next generation will have a higher average ability to survive and reproduce. At equilibrium the gain in each generation is offset by new harmful mutations. The first test of fitness is survival; but even among the survivors, natural selection operates through differences in fertility.
Although it acts on whole organisms, natural selection produces evolutionary effects by changing the relative frequencies of single genes. In each generation, sexual reproduction recombines genes so that all are tested in new combinations. The ultimate frequency of a gene depends on its average effect on survival and reproduction; if it is to become frequent, a new gene must be consonant with the major existing adaptations of the species. Natural selection is therefore conservative, tending usually to stabilize established norms.
Natural selection is inefficient for at least three reasons: (1) Many deaths or reproductive failures are due to chance. (2) Individual differences in fitness are often not hereditary. (3) Most hereditary differences in fitness are small. Some of this inefficiency can be overcome under artificial selection, but at a price. When it entails breeding from a few selected individuals, artificial selection may sacrifice both genetic stability and reserve variability. The artificial reproductive success conferred by the breeder on animals with commercially valuable traits may result in feeble or sterile strains. On the other hand, natural selection adapts a species only to its present environment or set of environments, and when the environment changes radically the species may become extinct. Man can foresee some changes in the environment and can, if he will, select for long-term fitness. In the last analysis this is probably a crucial advantage of scientific eugenics over natural selection.
The genetic stability of populations. Evolution is slow not only because natural selection is inefficient but because natural populations have a great inherent genetic stability. This stability is considerable even in small populations, for example, with a few hundred breeding individuals. Because of large numbers and small individual contributions to the next generation (compared with most species), civilized human populations should be very resistant to change.
Genetic stability resides primarily in the “gene pool” of a population. Each gene has a characteristic frequency, usually determined by a stable equilibrium between opposing forces of selection and mutation. Sudden changes in selective pressures may have more effect on complex traits than on the underlying gene frequencies, but even such traits are not likely to change fast. Thus, if lactation ceases to have survival value, its dependence on several physiological systems may make it vulnerable to mutations in any of a great many genes. Before any single genetic defect reached a frequency of 2.0 per cent, most women might have one or two rarer defects that prevented lactation. But an increase from 0.1 per cent to 2.0 per cent by mutation would take at least a hundred generations. Defects of lactation that were positively selected because of effects on other traits might increase ten times this fast, but they would be few and represent coincidence only.
Probably all human behavioral traits, except some grossly pathological ones, are controlled by multiple genetic factors and by the environment. Most of these traits are graded or continuous. Natural selection tends to eliminate both extremes in such a continuum and produces evolutionary change mainly from slight differences in fitness among the more numerous intermediate individuals. Thus, the gene pool retains a large reserve of variability and accommodates any new variations that do not have extreme effects.
Sources of variation. It has been suggested that ionizing radiation may speed human evolution by inducing more mutations. While mutations are the raw material of evolution, increased mutation rates now would probably do much more harm than good. First, nearly all mutations are harmful and must be eliminated by impaired fitness of the carriers, often extending over many generations. Second, nearly all of the possibly beneficial mutations have occurred before and are already so frequent that rare additions will not help. Third, the few new useful mutations would increase so slowly under moderate selective pressures that they would remain very rare for centuries.
Variations already present in human populations would suffice to carry human evolution forward a very long distance. New useful mutations that have arisen in the past few millennia are still in the early stages of response to natural selection. The great majority of variable genes, kept at intermediate frequencies by conflicting or inefficient selection, should have an immense potential for improving the species. Some useful genes may be mainly restricted to small populations or to certain races; intermarriage between nationalities and between races will make these generally available. Finally, man’s constantly changing environment under civilization changes the survival value of genes, making some useful that were previously neutral or harmful.
The role of an optimum environment. Early Darwinian enthusiasts supposed that natural selection was inevitably cruel and that human evolution could proceed only in a harsh environment. Diverse environments are desirable since they develop diverse potentials and, under natural selection, maintain genetic variability. But present human environments are often restricting and largely beyond control of the individual and even of the family.
Man’s future environment will probably be closer to the best than to the worst of present living standards. Eugenic planning for long-term adaptation should seek not only to equalize opportunity but to equalize it at a high economic and educational level. This would have no eugenic effect by itself but would enhance whatever selection was operative, either negative or positive.
Direction and choice in programs. A number of experts have warned that man may become dangerously dependent on medical technology. Such dependence, on a genetic basis, may develop gradually over centuries or millennia, but it is evident that throughout human evolution innate physical capacities have tended to deteriorate as compensatory mental abilities increased. In subhuman evolution, adaptability has repeatedly proved superior to specialized adaptation, and intelligence in its many aspects opens the way to almost unlimited adaptability. In any eugenic program, therefore, intelligence, broadly defined, should take precedence over physical fitness.
The above implied choice is an example of problems that would continually arise in eugenics. It is sometimes contended that the planning of human evolution would require superhuman wisdom. In practice, eugenics need not imply detailed foresight or genetic planning but would select for adaptability and diversity among variations already discernible. If the problems were faced one by one and periodically reviewed, they should be no more grave or insoluble than present political, educational, and social problems.
Dysgenic and eugenic environments. The environment is the instrument of natural selection since it sets the conditions for individual biological fitness, that is, the ability to survive and reproduce. For the continuation of our culture, and perhaps ultimately of the species, some other traits are as important as fertility. A society in which culturally important traits are positively correlated with fertility may be defined as a eugenic environment; the opposite is a dysgenic environment. One society may be eugenic within some social strata and dysgenic in others. Any discussion of a eugenic environment requires specification of the traits considered culturally important. One might assume that the greatest need in our culture is for traits leading to superior achievement in one’s chosen occupation. A thorough treatment of the subject would give weight to more specific traits such as intelligence, social maturity, and parental responsibility.
Proposed systems of selection
Promoting optimum expression of each person’s genetic capacities would not by itself constitute genetic progress. Eugenic selection, either natural or artificial, is also needed. Any deliberate program to promote eugenic selection would require much research before it could be instituted and careful monitoring of its progress.
Breeding programs. Next to preoccupation with race, the advocacy of artificial breeding programs has probably done most to make eugenics unacceptable. Early proposals were incompatible with concepts of conventional marriage and families as social units. Since the introduction of artificial insemination, the possibility of multiplying the progeny of selected men has become real. If artificial insemination from donors is practiced, all eugenists would agree that the donors should be carefully selected. But proposals for large-scale use of semen from a few great men (Muller 1960) may attach too much importance to fortunate combinations of genes that have little general value in the gene pool or in ordinary environments.
Assistance to selected families. British eugenists, especially, have advocated financial assistance, resembling scholarships, to parents with good eugenic prognosis (Blacker 1952, p. 307). This would enable them to have as many children as they wanted. Economically dependent families, with generally poorer prognosis, would be assisted in limiting their progeny.
With exceptions for grossly pathological heredity, eugenic prognosis in such a program ought to be based upon a couple’s social and cultural attainments and on physical and mental health of their earliest progeny. Discrepancies between attainments and genetic potential might be compensated by social transmission of traits, so that this eugenic program would achieve limited cultural improvement if not also genetic improvement. If future environments achieve near equality of opportunities, attainments will more closely reflect genetic capacities.
Automatic selection. Some eugenists have been dissatisfied with the potential for error or misuse in any arbitrary system of selection. Others see eugenic processes as requiring both broad application across all families and stability beyond that of most political systems. From these concerns have come suggestions for automatic selection: economic measures or social conditions under which natural selection will favor qualities of greatest value to society.
If the newest methods of contraception become widely available, they may eliminate nearly all unwanted pregnancies. This in itself would bring family size more in line with parents’ capacities for education and achievement (Osborn 1963a). The rewarding of fertility with uniform family allowances is not eugenically effective, but some countries offer other benefits. Highly effective automatic selection would require a more carefully planned eugenic environment (Osborn 1940). This might include high degrees of (1) social mobility, (2) individual opportunity, and (3) voluntary assortative marriage, that is, between persons with similar abilities. It might also require special educational, economic, and social measures to make child rearing more acceptable to socially competent persons and less so to the socially inadequate.
GORDON ALLEN
[Other relevant material may be found inEVOLUTION; GENETICS; RADIATION; and in the biographies ofDARWIN and GALTON.]
BIBLIOGRAPHY
BLACKER, CHARLES P. 1952 Eugenics: Galton and After. London: Duckworth.
CHUNG, C. S.; and MORTON, N. E. 1961 Genetics of Interracial Crosses in Hawaii. Volume 1, pages 134–138 in International Congress of Human Genetics, Second, Rome, Proceedings. Rome: Istituto G. Mendel.
DOBZHANSKY, THEODOSIUS 1962 Mankind Evolving. New Haven: Yale Univ. Press. ? An authoritative exposition for the general scientist of genetic principles relevant to human evolution.
Evolution and Man’s Progress. 1961 Dæedalus 90:409–586. ? A symposium. See especially pages 416–476, dealing with genetic evolution.
GALTON, FRANCIS (1883) 1952 Inquiries Into Human Faculty and Its Development. London: Cassell.
HALLER, MARK H. 1963 Eugenics: Hereditarian Attitudes in American Thought. New Brunswick, N.J.: Rutgers Univ. Press.
HOTCHKISS, ROLLIN D. 1965 Portents for a Genetic Engineering. Journal of Heredity 56:197–202.
MEDAWAR, PETER B. 1960 The Future of Man. New York: Basic Books; London: Methuen. ? A simple discussion of some central questions.
MULLEH, HERMAN J. 1960 The Guidance of Human Evolution. Pages 423–462 in Sol Tax (editor), The Evolution of Man. Volume 2: Evolution After Darwin. Univ. of Chicago Press.
OSBORN, FREDERICK H. (1940) 1951 Preface to Eugenics. Rev. ed. New York: Harper.
OSBOBN, FREDERICK H. 1963a Excess and Unwanted Fertility. Eugenics Quarterly 10:59–72.
OSBORN, FREDERICK H. 1963b Eugenics and the Races of Man. Eugenics Quarterly 10:103–109.
SHAPIRO, HARRY L. 1959 Eugenics and Future Society. Eugenics Quarterly 6:3–7.
WORLD HEALTH ORGANIZATION 1957 Effect of Radiation on Human Heredity. Geneva: The Organization.