This paper originally appeared in Research in Biopolitics, Vol. 5, Steven A. Peterson
Eugenics: Economics for the Long Run
By Edward M. Miller, PhD
and Al Somit, Eds., Greenwich, Connecticut; JAI Press, 1997, p. 391-416.
This paper originally appeared in Research in Biopolitics, Vol. 5, Steven A. Peterson
Paper requested for Recent Explorations in Biology and Politics.
Al Somit & Steven A. Peterson, Ed. JAI Press
Eugenics: Economics for the Long Run
by Edward M. Miller, PhD
Department of Economics and Finance
University of New Orleans
New Orleans, La. 70148
April 8, 1997
There is a simple economic argument for eugenics. Eugenics is defined as efforts to improve the gene pool in a particular population. Standard micro-economic theories of wages hold that a worker's wage equals the marginal product of his working time. Much textbook discussion of his marginal product focus on the quantities of cooperating factors: capital, land, and natural resources which labor has to work with. However, another important determinant is the worker's attributes and abilities. There is evidence that these are strongly affect by his genes (see below). It follows that efforts to maximize a nation's standard of living should try to improve its citizens' genetic quality, especially with regard to intelligence and other economically important traits. Improving the genetic quality of citizens calls for having those carrying the genes for desirable traits (as evidenced by their possession of the traits themselves) producing more than their proportionate share of that nation's children.
A secondary economic goal is to minimize the externalities in the economy resulting from the activities of one citizen affecting another citizen. An example would be minimizing the amounts that must be expended on welfare for those unable to earn the socially established minimum standard of living. Such people may be on welfare because of disease and handicaps, because low intelligence or personality problems make it hard to find and retain jobs, or because of drug addiction and alcoholism. Many of these conditions have an important genetic component.
Another important externality is criminal activity. Again it is known that from adoption studies and other sources that criminality has a significant genetic component (Rowe & Osgood, 1984; Lynn, 1996). As a result, an eugenics program can hope to reduce crime rates.
Notice the above arguments hold regardless of whether the intelligence of the population is believed to rising, falling, or remaining constant. If the intelligence is falling and expected to continue falling, it does follow that eventually something must be done or the maintenance of a modern industrial civilization will prove impossible. The available evidence is that those of higher IQ (who typically have genes that make for higher IQs) are having smaller families than those of lower IQ's (Herrenstein & Murray, 1994; Lynn, 1996; Miller, 1997a).
If a program of eugenics is to be introduced into modern countries, it will most likely be as a byproduct of births being restricted to restrain population growth. Thus, it will be argued below that in the long run society is faced with a choice between having the population restrained by misery, and having it restrained by conscious restrictions of births. Once the idea of preventing some births is accepted, it will then be natural to discuss the question of which births. It is then very likely that decisions will be based at least partially on preventing the births that are most likely to result in what that society regards as low quality citizens. This will be a eugenics program, although as will be pointed out some of the gains may arise from insuring that those children born are born into the families that provide better environments.
To introduce the case for eugenics consider Diagram 1. [Not available. Ed.] There is a simple income distribution on it with income increasing from left to right. Also shown is a certain level of income below which people fail to reproduce themselves. This is shown as a straight line. However, in practice it is probably a band, with women slightly below the line having only slightly less than two children surviving to adulthood. Women far below the line have relatively few children surviving to adulthood. Above the line the differences in survival to adulthood probabilities are probably small. But in the interests of simplicity, these complexities can not be shown.
What are the conditions for long run equilibrium? The first condition is that the population be stable. Obviously a continually growing population eventually exceeds the resources of the earth, or of the home country. This is not the place to get into debates about just what these limits are, or exactly when the world as a whole or particular country will come up against these limits. The purpose here is to show how societies will differ depending on how the state of zero population growth is achieved, and whether it is done by misery of the Malthusian type, or by eugenics.
It is important that the world is asymmetric, such that being far above the line probably does less for childhood survival than being below it. The diagram shows how with unrestrained fertility, the more unequal the income distribution, the higher the average income. The reason is that for population growth to be constrained by poverty to zero, there must be many below the poverty line. A given level of misery among those whose reproduction is being restrained by poverty is consistent with many different standards of living for those above the line. A more unequal distribution of income permits the average to be further above the line, consistent with any given amount of poverty, including that amount of poverty needed to keep the population stable.
If the distribution of income is to be completely equal, the average woman has to be at the poverty line, such that poverty prevents her from raising only slightly more than a single female offspring to reproductive age. It takes extreme poverty to achieve this outcome. Even in many poor third world countries the population is growing, and the typical woman much more than reproduces herself.
If income becomes more unequal, it becomes possible for most of the population to be far above the poverty line, while still allowing a high enough fraction of the population to be far enough below the poverty line to prevent population growth. This leads to the very unpleasant conclusion that for a nation to enjoy a high average income is consistent with that nation having a stable population only if that income is unevenly distributed. Only with high inequality will enough of the population be far enough below the poverty line to prevent population growth.
Without birth control, any attempt to raise the poor's living standard merely increases their children's survival rates, increases the population, and pulls the average standard of living back down. If income is redistributed from the rich to the poor, one predictable effect is that the rich live less well. Another is that the poor increase in number until rising misery returns the population growth rate to zero. This rather unpleasant vision is the standard Malthusian one.
Unfortunately, in the long run, without population control, attempts to eliminate poverty merely increase the population and reintroduce poverty. The obvious solution is to replace misery as a device for controlling population growth with some other program for limiting the birth rate and stabilizing population. While there is certainly something very intrusive about the government acting to limit births, it seems preferable to allowing population growth to be limited by poverty.
If there is to be some family size limitation, at least among certain families, perhaps we should be asking what criteria should be used to decide who should have children, and who should be prevented or discouraged from having children?
This may be a good point to refer to the evidence that many humans traits are strongly influenced by genes (Rowe 1994; Lynn 1996; Miller, 1997a). This evidence come from the science of behavior genetics. The first testable predication of a theory that variability in a trait is genetically influenced is that the trait will run in families. However, traits can also run in families because they are environmentally influenced, and each generation creates for their children an environment similar to the one they themselves were raised in. Thus, it is necessary to look for situations where environmental theories and genetic theories make different predictions.
One such situation is in adoptions, where the environment is created by the family of adoption, and the genes come from the biological parents. If there is no genetic influence, there will be zero correlation between the children's traits and those of the biological parents. To the extent the environment of rearing is influential, the adoptee's traits will be correlated with the family of rearing, while to the extent that genes are influential (or prenatal conditions) it will be correlated with the family of genetic origin.
Another method is twin studies. Here findings that monozygotic twins are more alike than dizygotic twins provides evidence of genetic effects. This is an example of a more general effect, in which, by examining the extent to which those who differ in genetic relationships resemble reach other, one can model the role of genetic factors. Especially impressive are the studies of separated twins that were raised apart. These frequently grow up to be quite similar in personality and intelligence (Bouchard, Lykken, McGue, Segal, & Tellegen, 1990; Pederson, Plomin, McClearn, & Friberg, 1988).
Due to space limitations, this is not the place to present all the evidence for the importance of genetic factors in intelligence and personality. However, there is strong evidence that most traits are genetically influenced (see for instance Rowe 1994 for summary evidence on the large number of traits for which genetic influences have been shown). Even what appear to be social attitudes have been shown to be affected by genes (Eaves, Eysenck, & Martin, 1989).
In general, the evidence for the role of genes in so many factors raises the possibility of controlling who bears children to influence the traits found in succeeding generations. This makes it useful to begin to discuss how eugenic policies might be carried out
In the short run, population growth can be restrained by encouraging smaller families by various voluntary means. By lecturing about the dangers of population growth and the environmental problems of a large population, some people may be persuaded to choose smaller families. However, these are likely to be the most responsible people. With each generation, the fraction of such responsible people is likely to decline. There is evidence that altruism (Rushton, 1980) is affected by genes. A voluntary program selects against such genes. Eventually this method will fail.
Because women that have many opportunities for high prestige jobs (professors etc.) frequently take them and choose to have few children, a common proposal for reducing the birth rate is to increase women's access to such jobs (Hoffman, 1975). Rhetorically this makes it easy to be both feminist and concerned about population growth.
For instance, in America the number of children per women 35-44 (when women have virtually completed their child bearing) is 1.6 for women with 16 years or more of education (college graduates usually), while it is 2.6 for those with 0-11 years of education (usually non-high school graduates), with those with in-between levels having 1.9 children for some college, and 2.0 children for high school graduates (Herrnstein & Murray, 1994). Presumably the college graduates delay the start of childbearing to complete their education (which may continue into graduate and professional school), and then frequently choose an interesting career over staying at home for child rearing. If these effects are caused by the education (rather than a common cause, such as a desire for a career causing the education), it would follow that providing more education for females would reduce population growth. If the whole population of the world had the US pattern of female education and birthrates, overpopulation would not be a threat.
Observations like the above lead many to argue that the solution (or at least a major part of it) for excessive population growth is to educate women, and to increase their opportunity to play high prestige roles in society. Women will then choose these roles over child bearing and rearing.
However, there are problems with this policy proposal (besides the obvious ones of whether the education is really causing the low birth rates, and how poor countries could afford to educate their women so well).
Unfortunately, the evidence is that much of what determines whether women will have access to high paying, high prestige jobs is genetic, notably the genes for intelligence (Jensen 1981; Herrnstein & Murray, 1994; Seligman, 1992, Storfer, 1990). Educating women and encouraging them to take up jobs that reduce their childbearing will work for the first few generations, but it will gradually lower the intelligence level of the population.
Herrnstein & Murray (1994) show that the average IQ of female college graduates was 111, versus 81 for the women who did not finish high school. The others were in between (103 for those with some college, and 95 for high school graduates). If we try to control population growth by encouraging the more intelligent women to choose careers over childbearing, in the long run the average intelligence must decline. This occurs because of the high heritability for intelligence. Because the intelligent women usually marry intelligent men, discouraging reproduction by intelligent women also reduces reproduction by intelligent men. Thus, this apparently desirable method for controlling population growth, so consistent with modern feminism, lacks long run viability.
However, there are other problems with any voluntary method for controlling population growth. It is likely that the drives for fatherhood or motherhood run in families for either cultural or genetic reasons. Those with weaker drives to be parents will be more readily persuaded to forgo parenthood. However, efforts to persuade people to voluntarily forgo parenthood merely assure that in the next generation will come disproportionately from those with stronger drives for parenthood. Thus, a voluntary program will eventually eliminate those who are easily persuaded to forgo parenthood. Those left will, for either genetic or cultural reasons (including religious ones), be unwilling to forgo parenthood. This is similar to the argument made above for appealing to the citizen's altruism to limit population growth. After the altruistic have been persuaded to limit their reproduction, and to gradually eliminate themselves, who is left that can voluntarily be persuaded to limit their births?
It is also true that some ethnic groups have higher birth rates than other (most likely for cultural reasons). If these differences persist, the mathematics insure that eventually the nation's growth rate will equal the growth rate of its fastest growing ethnic components. To use an extreme example, Hutterites (a sect that does not believe in birth control) may be the fastest growing group in a nation. If other groups can be persuaded to restrict their birth rates, given enough time the Hutterites will become any nation's dominant group. Then that nation's population growth rate will be that of the Hutterites.
Thus, eventually, population must stabilize and the alternatives are:
1. That this is done by restricting births by government coercion
2. This is done by poverty.
For the type of society that can result from poverty see Scheper-Hughes (1992) description of everyday life in Northeastern Brazil. She paints a disturbing picture in which most families live in poverty and infant mortality is very high, high enough so that parents become reconciled to losing children. Indeed, it appears as if they are subconsciously deciding to let some children die of malnutrition. Yet as bad as the situation described is, the population is still growing. The typical poor women still manages to more than reproduce herself. A even higher degree of misery would be required to limit population growth.
Besides limiting population growth rates, there is one other advantage to limiting family size. Right now the poorest families are the largest (Lynn 1996: Herrenstein & Murray, 1994). Mathematically, this implies that the percentage of the nation's children that are raised in poverty exceeds the percentage of the adults that are poor. In the US, child advocacy groups regularly point out the high fraction of the nation's children who are being raised in poverty. They consistently fail to point out how restricting the birth rates among the poor would help to solve this problem. The effect would be partially by lowering the percentage of children who are born into poor families. If this resulted in lowering family size among the poor, the low income families could spread their resources out more among their children.
Spreading the family's resources among fewer children would increase the per child amounts not only for economic resources such as money, but also of non-economic resources. It also permits (but does not guarantee) more parental time per child, and more supervision, which is usually believed to be good. For instance, it is know that children raised in large families more often grow up to be criminals, and in mainstream criminology this is attributed to such children receiving less parental supervision (Lynn, 1996)
If the government is to decide who is to have children, they may wish to decide on some rational criteria, so as to improve the gene pool or to accomplish other goals.
Admittedly, some might try to restrict population growth by an across the board restriction, thus apparently avoiding hard decisions about who should be allowed to reproduce. For instance, families might be somehow limited to two or three children (China now has a limit of one). However, for a stable population, two is too few, and three too many. In theory, one might alternate restriction of two with those of three for different generations (two children per family in several generations, and then a generation permitting three children per couple to rebuild the population). Likewise, if the number required for a stable population was 2.2, one might randomly assign certain families to the three child category, thus avoiding having to make choices on a rational basis. However, either of these procedures for avoiding making hard choices seems to forgo the advantages of selectivity for little reason.
If parental time for child rearing is very important, or if most adults want strongly to be parents, the goal might be families approximately equal in size. Any limits would then be to two or three children per family, and the selectivity would be limited to deciding on some basis which families would be allowed to have three children rather than two.
If the emphasis is more on insuring that children are born with the best possible genes, a greater degree of variability in family size might be considered desirable. Each family might be allowed a minimum of one child to give them the pleasures of parenthood, and possibly to provide society with whatever benefits may result from adults being parents (more conservative behavior among males for instance). The desired average of a little more than two children per family could then be achieved by having the selected parents have at least three children, and possibly more.
While different policies have implications for the percentages of the children that have occupied different birth orders, there is not now strong evidence that would justify preferring children of any particular birth order (Ernst & Angst, 1983). Clearly different strategies could change the percentage of middle children relative to first and last borns. Sulloway (1995, 1996) has presented evidence that first born are more conservative and later born more likely to be rebels, but it is not obvious which society should pick when it can choose.
Of course, if the goal is to provide an even more rapid genetic improvement while still retaining traditional family structures, those couples with the worse genetic endowment would be prevented from reproducing. The deficit would be made up for by much larger families among the couples with the better genes (however defined). This would require that many of these families have four or more children. Since there is no real evidence that large families are bad for children, this would seem to be an acceptable alternative.
Of course, if one is willing to explore unconventional family structures such as making more use of artificial impregnation, even where the wife has a husband who could father her children, or where the potential mother lacks a husband (as with single women or lesbian couples), there is scope for more rapidly spreading desirable genes. One might even consider cloning now that this has been shown to be possible in mammals (Specter, 1997).
Anything that slows the reproduction of those with genetic traits society does not want to perpetuate may be an eugenic policy. These aspects are not always discussed.
For instance, prison visits of wives for sexual purposes may encourage births by those carrying genes for criminality. Yet the discussions of this typically consist of the opponents saying that prison should be as unpleasant as practical, and that it is inconsistent with punishment to provide sexual access. On the other side, those in favor of conjugal visits typically argue they help to hold marriages together, prevent the spouse from being penalized, and perhaps help in managing the prisoners. Mention of any genetic effect seems to be missing.
It is sometimes proposed that rapists be castrated. This is generally proposed merely as punishment, but yet it should reduce the births of those with personality traits (possibly poor impulse control) that lead to rape and other crimes (for a discussion of the role of genes in rape see Ellis, 1989)..
Castration seems to work. Recidivism rates have been found to be 0 to 7.4% in a study of 2,055 European rapists (Bradford, 1990), which is far lower than the US recidivism rates, which have been reported to be as high as 40%. Given that castration is likely to be far cheaper than years of imprisonment, it might be used.
Perhaps even more effective in reducing rapes might be surgery that prevented erections by cutting relevant nerves. This would eliminate the reinforcing effects of fantasies accompanied by masturbation, probably reducing the motivation for rape and other sex crimes. This is purely a speculative proposal at this stage, but one that should be the subject of some discussion.
In principle, castration might be used for other violent crimes also. It has the attraction of being relatively low cost. If there is a substantial genetic basis for most crimes, and the evidence is that there is (Lynn, 1996), castration would reduce the number of offspring left by such criminals. If it is desirable to reduce the rate of population growth for other reasons, as was argued above, criminals would seem to be good ones to deprive of the benefits of fatherhood.
Of course, castration of criminals might deprive their wives or girl friends of parenthood. It is likely in many case they would become pregnant even without artificial insemination. However, with the availability of artificial insemination, they would be expected to frequently choose artificial insemination rather than remaining childless. The result would be replacing the sperm of a criminal with what could be a very high quality sperm. Obviously that would tend to reduce the frequency of the genes most closely related to criminal activity.
One side benefit of such a program would probably be selection against low intelligence. It is known that arrested criminals tend to have below average intelligence. For instance, Herrenstein & Murray (1994, p 248) found that 12% of the male whites in the very dull category were in a correctional facility when interviewed versus 3% for the whole sample.
There are a number of ways people might be induced to limit births that would not involved coercion (other than to pay the taxes to finance the programs). Most such programs would probably have an eugenic effect since those with lower incomes or shorter time horizons would probably find any given incentive program more attractive.
Payments for sterilization might be offered, say $5,000 or $10,000. These sums would be attractive to those who have a weak desire to leave descendants. Very likely such programs would select for other desirable traits such as a tendency to weight income in the distant future less than in the present. Banfield (1974) has argued that a greater desire for current pleasure (related to the economist's concept of time preference) lies behind many of the inner city problems. For instance, if one needs $20 for a date tonight the easiest way to obtain it is to snatch someone's purse. Admittedly, repeated purse snatching is likely to end in a jail sentence, but that is sometime in the distant future. At a high enough interest rate, stealing the purse becomes rational.
Likewise, drug taking brings immediate pleasure even if at the cost of future addiction. Sex brings immediate pleasure even if the cost is unwed motherhood, or for the father, financial responsibility for children. Watching TV is more pleasant than studying, but studying has long run returns in higher income. Maintaining real estate takes time, but over the long run it makes for a more comfortable home. Saving (and forgoing use of credit) reduces current consumption, but increases future consumption. Creating a small business often means putting in long hours and doing without many pleasures. However, eventually, the small business may succeed. One can imagine many such examples.
There is very little solid research on whether time preference has a genetic basis. It is known to vary with ethnic background. For instance, in Trinidad children of Indian descent (ancestors from India) are less willing to accept a small piece of candy now rather than a larger piece of candy in the future than those of African descent (Mischel & Metzer, 1962). However, since most personality traits are strongly affected by genes with a substantial heritability, it is very likely that the ability to defer gratification is a trait with a genetic component.
If a desire for immediate gratification plays a role in criminality, as it appears to (Wilson & Herrnstein, 1985), it is to be expected that restraining the reproduction of convicted criminals would also tend to restrict the reproduction of those with a short time preference.
It is very likely that many modern methods of birth control select for a desire for immediate gratification. Consider for instance the simple condom. Using this for birth control requires stopping the sequence of events (often seduction) that lead to impregnation to put a condom on. Those who have a strong desire for immediate gratification are much less likely to do this. The same argument applies to inserting a diaphragm, coitus interruptus, or using sponges. Even using birth control pills requires obtaining the pills in advance, and remembering to take them at the right time.
A significant fraction of births represent failures of birth control (Van Court, 1983). For the United States, the Kost & Forrest (1995) analysis of the National Survey of Family Growth reported that 36% of births were unplanned. For those with less than twelve years of education, 58% of the births were unplanned versus only 27% among college graduates. Besides the obvious dysgenetic effect on intelligence, these probably have a dysgenic effect in that the families that who have children through birth control failure are probably less willing to defer gratification, and have a lower ability to plan ahead. Also, it is very likely that inability to defer gratification goes with a lower intelligence. Incidentally, the high fraction of births that are unplanned suggests that improved methods of birth control that are easier may have a significant eugenic effect.
One other trait that may go with accidental pregnancies is drinking alcohol. Many people are inhibited about sex and loosen up with alcohol (or are plied with alcohol by their potential sex partners). Alcohol in general lowers inhibitions. These lower inhibitions are both towards having sex, and towards having unprotected sex. In the modern world, where most children born are raised to sexual maturity, the fact that birth control methods are readily available to most everyone to be used or not, may act as a selective agent for alcohol consumption. The reason is that people who are drunk, or merely under the influence of alcohol are less likely to use birth control, and are therefore more leave offspring with the same propensity for alcohol consumption. However, this desire for alcohol also goes along with alcoholism, and this makes a mate less desirable (and intoxication can make the sex act harder for males).
Boulding (1969) has proposed transferable licenses for child bearing, each couple to get 2.2 licenses. They could then be bought or sold. Those who valued children most would have the larger families (probably a good in itself). In practice, many poor people and those with short time horizons would sell their licenses for the money. This would have a desirable eugenic effect.
Barry (1969) has proposed payments for potential parents who have no more than two children, such payments to be proportional to income. He bases the proposal to make the payments proportional to income on a desire to have the upper and middle classes restrict their fertility as much as the lower classes. His rationale for trying to restrict fertility as much in the upper and middle classes is to maintain the opportunity for upward mobility for the poor. Interestingly, this paper, although appearing in a journal stating on the cover that is was formerly the Eugenics Quarterly, displays no awareness that restriction of fertility among the lower classes would increase the genetic quality of the population. However, his explicit rationale for trying to avoid disproportionate fertility restriction among the lower classes does point out a possible disadvantage to eugenics programs. If fertility is disproportionately restricted among the lower classes as a successful eugenics program would do, there is likely to be more social downward mobility, with more of the population feeling they were ranked lower than their parents (and they will be correct). If moving downwards in the social hierarchy makes people feel bad (and it does), this is a disadvantage to an eugenics program.
Any plan that offers large sums of cash for sterilization, or for restricting child bearing, would reduce the birth rates most among those with a strong desire for current consumption. Such large cash payments would be especially attractive to drug addicts who often need money to purchase drugs. There could be expected to be effects on future rates of drug abuse from such an eugenics program.
If it were politically possible, one might even trade drugs for sterilization or implantation of a birth control device, or at least provide enough drugs so that there would not be withdrawal problems around the time of the sterilization.
Since crack, alcohol, (and probably other drugs) affect the fetus, there would be strong social savings if these addicted women could be prevented from having children. It could also slow down the spread of AIDS, which is frequently transmitted from mother to child. Notice that such benefits are environmental in nature.
An obvious idea is to tie the receipt of welfare to using a drug which prevents having additional children while on welfare, such as Norplant. Given the correlation of being on welfare with low intelligence, and probably with other undesirable genetic traits, such a proposal would improve the nation's genetic stock. Given the difficulty of knowing whether promises to use birth control are being observed, tying receipt of welfare to using most methods of birth control is probably infeasible. Penalizing mothers for having babies after they promised not to would either end up penalizing the children, or force the mothers into having abortions.
It is to be expected that any measure that reduces the pool of low IQ, uneducated individuals would reduce the competition for the jobs such people can do. Such a program should reduce the unemployment rate, and raise incomes among the low IQ part of the population.
The final outcome of such birth control would be to reduce inequalities by two mechanisms.
1 Reducing the number of those with traits leading to low income (low IQ, short time preference, etc.) in the society. This raises the weighted average skill level.
2. By raising the wages rates for unskilled labor. It is a standard prediction of economic models that reducing the supply raising the price. It follows that reducing the supply of low wage labor would raise the wage rates for such services.
Although the word eugenics is very unpopular among intellectuals, there may not be as much opposition among the ordinary voters.
One Texas legislator in an informal poll found 3,533 to 2,604 in favor of sterilization for welfare moms with 3 or more children. (Reilly, 1991, p.161). The Boston Globe found, in a call in telephone poll, that 49% supported sterilization of the mentally ill.
China has apparently adopted a sterilization law targeting mentally retarded parents in one province (Reilly, 1994, p. 164). While China is politically quite different from the United States, this still shows that such actions may be possible
Singapore has announced eugenic programs aimed at promoting births by the better educated (Chan, 1987), and in particular by graduate women. There was also announced a program to reward low income families under 30 with less than two children for being sterilized with US$4,000 as a down payment for a government low cost apartment.
Of course, there are arguments against eugenics programs. Government power over private citizen's lives is always subject to abuse. So history teaches. US state run programs seem to have had problems with some sterilizations that were not for good eugenic reasons (Reilly, 1991). Any government program is going to make numerous mistakes and possibly suffer from some corruption. Certainly it has not always been known which traits were genetically influenced, and there were some sterilizations done under the various laws that probably do not contribute to improving the genetic stock. For instance, there is a case of a woman who was the offspring of incest, but apparently otherwise unhandicapped, being sterilized.
Currently, we are far from having much knowledge of which genes influence particular traits, or from knowing all the traits that are subject to genetic influences. If we were given complete copies of the genetic sequences for two individuals we could not tell which one we preferred. That is true. However, such a high level of knowledge is not needed for a useful eugenics program.
It is generally known that many traits are genetically influenced (see above) and people generally agree on which direction is good. For instance:
1. High intelligence is good.The above provides a basis for deciding whose reproduction to encourage. At this point we could proceed with a start on programs, hoping to improve knowledge in the future.
2. Self control is good.
3. Criminality and rape are bad.
4. Most diseases are bad.
One theoretical concern is that many traits may be influenced by pleitropic genes such that selecting for a desirable trait also selects for another trait that is undesirable. Thus there could be unintended consequences from an eugenics program.
To illustrate the type of problem that is theoretically possible consider myopia. This is widely considered to be a genetically influenced condition. It is known to run in families, and twin studies show it to have a high degree of heritability (Curtin 1985). However, it is also known that high intelligence and myopia go together (Teasdale, Fuchs, & Goldschmidt, 1988; Rosner & Belkin 1987; Benbow & Benbow 1984, p. 484 and 1986). High intelligence is also known to be a partially genetic trait. The evidence is that the two genetic traits are pleitropic, with one gene affecting both (Cohn, Cohn, & Jensen, 1988). One possibility is that the close work that results from reading and studying leads to myopia. Another, which the writer has proposed, is that a single gene (or gene complex) affects both brain size and the size of the eyeball (which is embryologically derived from the same tissue as the brain) and this produces the correlation (Miller 1992, 1996d).
Now, if someone tried to discourage those with myopia from reproducing, a byproduct would be selection for lower intelligence. This would be unfortunate, since myopia is relatively easily handled with corrective glasses. Of course, enough is known so that the above mistake appears unlikely. About the only way it could be made would be for a version of political correctness to make selection for intelligence impossible, while selection against genetic disease related conditions was promoted.
A slightly more difficult problem is the possibility that genes that promote certain forms of mental illness are also genes that contribute to genius or originality. There is some evidence for this proposition (Eysenck 1995; Goodwin & Jamieson, 1990; Karlsson, 1991). Efforts to discourage reproduction by those with manic-depressive illness or schizophrenia, both of which have been shown to have a genetic component in twin studies, might produce adverse effects on creativity.
One can also imagine other unanticipated genetic problems. Many polymorphisms are believed to protect against one disease but to increase vulnerability against another. They survive in the population over the long run because whenever a particular allele become more common, the diseases it makes for vulnerability to become more common, and the allele making for vulnerability is selected against.
It must be admitted there is a chance that this could happen. If we knew that a particular allele made for vulnerability to a particular well-publicized disease, say AIDS, there might be pressure to discourage reproduction by carriers of such an allele. Indeed, a mutation that appears to protect against AIDS has been recently found (Kolata, 1996). This could increase vulnerability to another disease where the effect was not known, or just possibly a new disease would then emerge that could then spread more rapidly. It is also conceivable that a gene for a desirable trait may also increase vulnerability to a disease.
Another theoretical argument that is sometimes heard is that genetic diversity is needed for further evolution and that eugenic programs might reduce this diversity, eliminating a desirable allele. The analogy is sometimes made with certain crops where the genetic diversity may have been greatly reduced, increasing the vulnerability to certain diseases.
However, in any one generation any realistic program will make only minor changes in the gene pool. This will give plenty of time to reverse direction if unintended consequences emerge. Desirable genes are unlikely to be eliminated from the gene pool by a feasible short-term eugenics programs. Any appreciable reduction in diversity is so far in the future that little concern is needed for now.
Frequently those who object to eugenics programs to reduce births in families suffering from a particular problem assert that the targeted social problem is environmental in origin. For instance, if it is proposed to raise average intelligence levels by reducing the number borne to parents with low intelligence, it may be argued that low intelligence is of environmental origin. It is definitely true that there is an environmental component to most social problems, including low intelligence and poverty.
However, it does not follow that eugenics programs cannot reduce problems caused by social causes. Whenever a problem is known to run in families, reducing the number of children in families with the problem should reduce any problem's incidence. Suppose low intelligence was caused by a unknown type of bad parenting that was in certain families, with each child as an adult copying its own parents' bad parenting. Increasing the fraction of children in the families that practiced good parenting (which might be determined by the parents themselves being of high intelligence) would still increase intelligence in the next generation. An environmentally caused problem whose exact mechanism is unknown can be handled by decreasing the fraction of births in certain families, just as a genetically caused problem can be handled. In most cases the policy implications of environmentally and genetically caused low IQ are the same as far as who is encouraged to have children. The key question for predicting the effects of a program is the correlation between the IQ's of parents and children. Knowing the causes of this correlation is not critical.
There are a few cases of low IQ known to be due to environmental causes (say an accident that injured the brain) where there would be no eugenic objection having children. However, such cases are rare. Even in these cases, one might feel that it was best for the child not to have a low IQ parent and wish to discourage childbearing.
Eugenic programs that work by manipulating family size can be expected to work, although slowly and over a period of generations. If there are unrecognized environmental factors being transmitted from parents to children, such programs will also increase the percentage of children exposed to such positive environmental effects.
Westman (1994), convinced that bad parenting leads to most problems has written a book which proposes licensing parents. Some of his proposals would probably end up having eugenic effects. Those who could not get licensed as parents would probably be of genetically low intelligence, and the proposal would end up having positive eugenic effects.
Admittedly, if it were known that there existed a particular environmental factor that affected intelligence, an obvious alternative would be to deal directly with the factor. For instance, if it turned out that rocking children to sleep promoted intelligence (the reference is to speculations in Storfer 1990), it would still be true that we could increase the percentage of intelligent children in the next generation by encouraging parents who were intelligent (who had probably been rocked to sleep themselves). Even more efficient would be to encourage those who planned to rock children to sleep to have large families. Of course, if we did have knowledge that such a simple intervention raised intelligence, we would not choose to exploit it by manipulating family size depending on their proclivity to rock children to sleep. Instead we would have a program to teach mothers to rock their children to sleep, or perhaps we would discover that mothers themselves had already read the research results and were rocking their children to sleep.
However, as of now we know of few environmental interventions that do much for children's intelligence, or that improve other aspects of their personality. Spitz (1986) has traced the history of efforts to raise intelligence by environmental means. There is a long series of episodes in which some intervention was proposed, received much favorable publicity, and was then found to have little permanent effect. The most recent such episode has involved early childhood programs of the Head Start type. These were found to temporarily raise intelligence scores. However, once removed from the program the children were found to gradually return to the low level of performance of those who had never been in such programs.
That there is little hope for environmental manipulation in raising IQ is shown by adoption studies in which even the intervention of putting children into whole new environments seems to have little effect on their adult intellectual performance, although some effect on childhood performance is seen.
For instance, Loehlin, Horn, & Willerman (1989) found that unrelated adopted siblings, when tested at 13-24 years of age, had essentially no resemblance to each other (r=-.01). Scarr and Weinberg (1978) studied children aged between 16 and 22 in adopted and biological families. In the adopted families the correlations were .16 between adopted father and child, .09 between mother and child, and -.03 between siblings. Children who were raised from infancy together differ as much as unrelated pairs of children. This provides powerful evidence that the environment of rearing has little impact on adult intelligence. If the massive intervention of changing the family of rearing (which also affects things like schooling) has little impact, the chances seem small that more modest interventions that affect only schooling, housing, health, or a similar variable will have much impact.
The same study showed correlations between siblings of .35 when raised in biological families, and .40 between father and child, and .41 between mother and child. Since it was argued above that the family of rearing had relatively little impact, most of these similarities must be because parents, children, and sibling share genes. This, of course, is evidence for genetic effects.
However, regardless of what is causing the resemblance between parents and children in biological families (which are the vast majority of families), the fact of such resemblance suggests that increasing the percentage of children borne into high IQ families will raise the intelligence of the next generation. One should not hope for a massive rate of improvement, but the potential for improvement is there.
It is here that one finds the chief political problem with eugenic programs. At best one can hope for only slow increase in the frequency of genes for a trait. If a politician is looking for something he can announce that will plausibly make a difference by the next election, or even by when he retires, eugenic programs will seldom appeal. Given the ease of confusing correlation with causation, and the large number of variables that can be correlated with social outcome variables, there will virtually always be some intervention that can be plausibly argued to have the potential for having a quicker impact. Some may even be plausibly claimed to capable of solving the problem, eliminating the need for a eugenics program. Since there is usually significant prestige and money associated with sponsoring such an intervention, there can be expected to be partisans for one or more such interventions arguing for them. For a politician looking for a program he can announce that will plausibly be dealing with a serious social problem, there will usually be several candidate programs supported with at least correlational evidence (even if no one has yet done a well controlled intervention study).
How are such partisans to be defeated, or how is one going to determine whether they should be defeated (since there is a small chance that one of their interventions will indeed prove very effective)? It is probably wise to press for actual experimental evidence (from studies with adequate controls) that such programs work. A problem is that partisans are likely to be so convinced that their programs work that they will argue that it is unethical to deprive some citizens of the program in order to provide a control group. Yet this must be done if we are to know which, if any, interventions work. When the interventions take the form of providing poorer children with what the educated prosperous families already enjoy, the evidence from the low correlations of adopted children with siblings can be used to suggest the programs will not work.
Eugenic type programs are unlikely to be adopted because of arguments that they are solutions for social problems. They work too slowly to be attractive for this alone. They are likely to be adopted when there is agreement that birth rates are too high, and that some will have to forgo child bearing. This then forces consideration of the question of who should forgo childbearing. One can then argue that the parents which do not exhibit the traits that society values, and (who are likely to be carrying undesirable genes), are those that should forgo child bearing.
The biggest political problem with eugenics now is its association with Nazi Germany and the claim that the extermination of the Jews was part of their eugenics program (see Kuhl, 1994). While there is not space here for a full answer, it appears the Nazi Anti-Semitism was why they tried to exterminate the Jews (see Saetz, 1985). Given the strength of that drive, the outcome would have been the same regardless of their views on eugenics.
The other major political problem is that desirable genes are distributed unequally among the racial groups, as is the socioeconomic status and phenotypic traits that would be used as surrogates for the possession of desirable traits. The trait that is most economically important is intelligence (Herrenstein and Murray, 1994; Seligman 1992). There is no real dispute that races differ in measured intelligence, and not much dispute among experts on intelligence that the difference is real in the sense that it is reflected in unequal school and job performance. There is more debate as to what causes it.
Even in the 1980's the experts were divided three to one in favor of explaning for black/white differences in IQ by both genetic and environmental causes (Snyderman and Rothman, 1988).
Perhaps the most powerful evidence for a difference in the frequency of genes affecting intelligence is provided by the outcomes of the experiment of adopting black children into white households, where at age 17 the gap between black and white adoptees was approximately that which is found when children of each race are raised in families of their own race (Levin, 1994; Lynn, 1994).
Among the recent pieces of evidence that at least part of the racial difference is genetic is the Jensen & Johnson finding (1994) that the black/white difference in head size in children disappeared when intelligence was controlled for. Jensen (1994) also found that the extent of the g loading on a test (roughly how well the test measures only intelligence) was significantly related to the correlation of the test with head size.
There are numerous other reasons for believing that the genes affecting many socially important traits differ in frequency between the races (Miller 1994b, c, d, 1995a, b, 1996a, b, 1997b, 1997c; Rushton 1995).
It follows that any eugenics program in the United States that does not contain special provisions for blacks will restrict the reproduction of blacks more than it does of whites. In the current environment, such a program would be denounced strongly as racist. This alone would prevent such a program from being adapted. Of course, programs could be designed to provide quotas for different racial groups, or to make other special provisions. On the other hand, if the program offers voluntary payments for sterilizations or for having Norplant inserted, blacks and other low income groups would receive a disproportionate proportion of the financial incentives. However, this is unlikely to keep the current black leadership from objecting vehemently to such programs.
However, in the developed world of the US, Europe, and Japan there does not seem to be the compelling need to restrict family sizes. Birth rates are near, and often below, that needed to keep the population from growing. In these circumstances, the power elites will see eugenic programs as restricting their freedoms and are unlikely to be supportive. This leaves one with the somewhat pessimistic conclusion that a slow deterioration in the genetic quality of the developed world's population is likely to continue. What could change this?
Probably the most likely thing to change is the state of scientific knowledge. As time passes, more and more knowledge of genetics accumulates. More importantly, the molecular genetics revolution makes it likely that someday the working of the relevant genes will be discovered at the molecular level. It is also possible that the biology behind intelligence and certain forms of behavior will come to be understood well enough so that it will seem very plausible that genes are determinative.
For instance, Tu & Israel (1995) have found that alcohol consumption by Orientals in North America is predicted largely by a single gene. Berman & Noble (1995) have found reduced visuospatial performance in children with the D2 dopamine receptor A1 allele. Plomin et al (1995) have found evidence for genetic markers being related to IQ. Skuder et al (1995) have found evidence for a polymorphism in mitochondrial DNA that is associated with IQ. Reed et al. (1995) have shown lower cognitive performance in normal older adult male twins carrying the apolipoprotein E*4 allele. The apolipoprotein E*4 allele (Kamboh, 1995) is known to increase susceptibility to Alzheimer's disease. Keltikangas-Jarvinen, Raikkonen & Ki (1993) have shown apolipoprotein E phenotypes affect temperament in children, adolescents, and young adults. Bertilsson et al (1989) have shown that there are personality differences that correspond to differences in Debrisoquine hydroxylation (a genetic difference). Lesch et al (1996) have very recently presented evidence that differences in a gene affecting the regulation of serotonin affects anxiety. As findings of this type accumulate, it will be easier for the public to accept the idea that genes affect behavior.
As another example, the author has put forward a theory in which intelligence depends on the extent of myelination (Miller 1994a, 1996c). The theory is supported by extensive empirical analysis and explains a wide variety of facts. It is also empirically testable by directly measuring the amount of myelin after death for the more intelligent, and comparing it with the amounts found in the less intelligent brains. Likewise, there is now a large literature showing that brain size (and head size as a proxy for brain size) is correlated with intelligence (Miller, 1992; Rushton & Ankney, 1996; Wickett, Vernon, & Lee, 1994; Willerman, Schultz, Rutledge, & Bigler, 1991). As such evidence becomes better accepted, more people will find it easy to believe that such variables as brain size or myelination are subject to strong genetic effects. Hopefully, this in turn will make it easier to accept that intelligence is itself genetically influenced. For those that doubt that brain size has substantial heritability there is already evidence that head size has substantial heritability (Rushton & Osborne, 1995).
Another possibility is that technology may make some types of eugenics more feasible, and they become popular. Modern fertility enhancing technology is expensive and is primarily used by families of high income who badly want a child. Thus it probably has some eugenic effects.
Artificial insemination has a potential for being used for eugenic purposes. In many couples where the male has inadequate quantity or quality of sperm, the couple chooses to use artificial insemination in order to have children. There is probably some positive eugenic effect in the current sources of sperm since many are reported to be near universities or medical schools where the population would be of above average intelligence. However, while great care is taken to screen donors for genetic diseases and for sexually transmitted diseases, it is not now customary to use an intelligence test to select donors of high intelligence, although such tests would be easy to administer.
Yet given the willingness of parents to pay for expensive college educations for their children, it would surely seem worthwhile for the potential parents to pay the slightly higher costs of higher quality sperm. The costs would be slightly higher because not only would there be the cost of testing, but it would probably be necessary to pay more to donors in order to have a larger pool to select from. However, the cost would still be minor in relation to the total cost of conceiving and rearing a child. If well-heeled parents seek the best designer jeans for their offspring, why shouldn't they seek the best genes?
However, one sperm bank has received considerable publicity by seeking high quality, intelligent donor, originally Nobel prize winners. (See Grahm, 1983) There is no reason other sperm banks could not adopt similar methods. Since one sperm donation can supply several inseminations and donors can be expected to donate repeatedly, the cost of seeking high quality donors would be low.
In spite of the apparently very high benefit-cost ratio from selecting sperm on the basis of the donors intelligence, an Italian doctors group has decided that there should be no selection of sperm based on the social, economic or professional standing of the donor (Montalbano, 1995). Yet, these are all cheaply ascertained surrogates for intelligence, and other genetic traits that contribute to obtaining high social and professional standing.
Should Lesbians or single women become mothers by artificial insemination? If the sperm used is of high quality, it is very likely that the offspring will be of high intelligence, and unlikely that they will become public burdens. Should post-menopausal women have babies using advanced technology and their husbands sperm, as a 62 year old women recently did in Italy (Montalbano, 1995). Given the high cost of such technologies, it is very likely that their husbands had genes for high intelligence. Yet this measure was to be banned by the new Italian doctors code, as was artificial insemination after a partner's death .
More speculatively, it is now feasible to fertilize a woman's egg outside of the womb and then implant it. Right now the procedure is used only for couples who would otherwise be infertile. One can imagine a time when the wealthier couples have potential embryos checked for genetic problems, or perhaps have several embryos fertilized and then select the one for implantation that appears genetically the best.
Mammalian cloning has been shown to be possible, and if applied to humans will probably involve the cloning of high IQ individuals, even if the basis for choosing an individual to clone is something else (being the dictator, or having extraordinary talents in certain areas).
It is also conceivable that selective abortion might be used to avoid bearing children that carry what are considered undesirable combinations of genes. This is done to a limited extent now for Downs syndrome and certain other genetic conditions. If such expensive procedures are adapted they may be adapted by the wealthier couples rather than the poorer ones.
A factor that could lead to eugenics programs is that the power elite is likely to have the genes that we would like to encourage. This elite will be very receptive to rationalizations that will permit those who wish for large families to have them. A rule that exempted those of high IQ from family size restrictions would virtually always exempt the elite (politicians, executives, professors, union leaders, army officers etc.) from family size restrictions. Likewise, programs that discourage those convicted of crimes (or suffering from alcoholism or drug abuse) from having children are unlikely to impact heavily on the ruling classes. If circumstances emerge where nationwide family size restriction is desirable, eugenics may come to provide the rationale for the rule makers to exempt themselves from the rules.
There is sufficient knowledge now about the importance of genetic factors to indicate that, over time, income could be raised by eugenics. Such a program is not politically feasible now, but someday it may be, especially when overpopulation makes it necessary to restrict births. Eugenics may then become popular among the ruling classes because it provides a rationale for exempting them from the restrictions that would otherwise apply.
In practice, eugenics programs may take the form of trying to reallocate child bearing from families with undesirable traits to families with desirable traits. This should increase for the next generation the proportion of the population with desirable traits. Although such programs are traditionally referred to as eugenics programs (i.e. ones to improve the population genetically), such programs can be expected to work for traits transmitted within families from parents to children regardless of whether such transmission is by genetic means or by other means. All that is necessary to predict the success of such programs is to know the correlation to be expected between parental traits and those of the offspring, information that is already available for many traits.
Even when the degree of political support for direct eugenic measures is weak (say only 20% of the population would vote for them) consideration of the eugenic effects of alternative ways of accomplishing certain goals might change the ranking of alternative methods for accomplishing these goals, and produce some eugenic benefits.
Banfield, E. C. (1974). The Unheavenly City Revisited. Boston: Little Brown.
Barry, L. D. (1969). Population policy: Payments for fertility limitation in the United States. Social Biology, 16, 239-248.
Benbow, C. P. & Benbow, R. M. (1984). Biological correlates of high mathematical reasoning ability, In G. J. De Vries (Ed.), Progress in Brain Research, Vol. 61. Amsterdam: Elsevier Science Publishers.
Benbow, C. P. & Benbow, R. M. (1986). Physiological correlates of extreme intellectual precocity. Mensa Research Journal, 21 , 54-87.
Bertilsson, L.; Alm, C., de Las Carreras, C., Widen, J., Edman, G, Schalling, D. (1989). Debrisoquine hydroxylation polymorphism and personality. Lancet I, 555.
Berman, S. M. & Noble, E. P. (1995). Reduced visuospatial performance in children with the D2 dopamine receptor A1 allele, Behavior Genetics, 25, 45-58.
Bouchard, T. J., Lykken, D. T., McGue, M, Segal, N. L. & Tellegen, A. (1990). Sources of human pyschological differences: The Minnesota study of twins reared apart. Science, 250, 223-228.
Boulding, G. K. (1969). Marketable licenses for babies, in Hardin, G. (Ed.) Population Evaluation and Birth Control. San Francisco, W. H. Freeman as cited in Chadwick, R. F. (Ed) Ethics, Reproduction and Genetic Control, p. 181.
Bradford, J. (1990). The antiandrogen and hormonal treatment of sex offenders. In W. Marshal, D. Laws, & H. Barbaree (Eds.), Handbook of Sexual Assault: Issues, theories, and treatment of offenders. Pp 297-310. New York: Plenum.
Chan, C . K. (1987). Eugenics on the rise: A report from Singapore. in Chadwick, R. F. (Ed) Ethics, Reproduction and Genetic Control, pp. 164-171.
Cohn, S. J. Cohn, C. M. G. & Jensen, A. R. (1988). Myopia and intelligence, a pleiotropic relationship. Human Genetics, 80, 53-58.
Curtin, B. J. (1985). The Myopias, Philadelphia: Harper & Row.
Eaves, L. J., Eysenck, H. J. & Martin, N. G. (1989). Genes, Culture, and Personality. London: Academic Press.
Ellis, L. (1989). Theories of Rape. New York: Hemisphere Publishing.
Ernst, C. & Angst, J. (1983). Birth Order: its Influence on Personality. New York: Springer-Verlag.
Eysenck, H. J. (1995). Genius : The Natural History of Creativity. Cambridge: Cambridge University Press.
Goodwin, F. K. & Jamieson, K. R. (1990). Manic-depressive Illness. New York: Oxford University Press.
Graham, R. K. (1983). Interview with Robert K. Graham on The Repository for Germinal Choice. The Eugenics Bulletin, Winter, 1983, 1-11. Future Generations site www.eugenics.net
Herrnstein, R. J. & Murray, C. (1994). The Bell Curve: Intelligence and Class Structure in American Life, New York: The Free Press.
Hoffman, L. W. (1975). The employment of women, education and fertility. In Mednick. M., Tangri, S., & Hoffman, L. (Eds). Women and Achievement: Social and Motivational Analyses. Washington, Hemisphere Publishing.
Jensen, A. R. (1994). Psychometric g related to differences in head size, Personality and Individual Differences, 17, 597-606.
Jensen, A. R. & Johnson, F. W. (1994). Race and sex differences in head size and IQ, Intelligence, 18, 309-333.
Kamboh, M. I. (1995). Apolipoprotein E polymorphism and susceptibiity to Alzheimer's disease, Human Biology, 67, 195-215.
Karlsson, J.L. (1991). Genetics of Human Mentality. New York: Praeger.
Keltikangas-Jarvinen, L., K. Raikkonen, & T. L. Ki (1993). Dependence between apolipoprotein E phenotypes and temperament in children, adolescents, and young adults. Psychosomatic Medicine, 55, 155-163.
Kolata, G. (1996). Gene mutations may once have warded off diseases. New York Times, December 3, 1996.
Kost, K. & Forrest, J. D. (1995). Intention status of U.S. births in 1988: differences by mothers' socio-economic and demographic characteristics. Family Planning Perspectives, 27,11-17.
Kuhl, S. (1994). The Nazi Connection: Eugenics, American Racism, and German National Socialism. Oxford: Oxford University Press.
Lesch, K., Bengel, D., Heils, A.,Sabol, S., Greenberg, B. D., Petri, S., Benjamin, J. (1996)Association of anxiety-related traits with a polymorphism in the serotonin transporter gene regulatory region. Science 274, 1527-1531.
Loehlin, J. C., Horn, J. M., & Willerman, L. (1989). Modeling IQ changes: Evidence from the Texas adoption project. Child Development, 60, 993-1004.
Levin, M. (1994). Comment on the Minnesota transracial adoption study. Intelligence, 19, 13-20.
Lynn, R. (1994). Some reinterpretation of the Minnesota transracial adoption study. Intelligence, 19, 21-28.
Lynn, R. (1996). Dysgenics: Genetic Deterioration in Modern Populations, Westport: Praeger.
Miller, E. M, (1992). On the correlation of myopia and intelligence, Genetic, Social, and General Psychology Monographs, 118, No. 4, , 363-383.
Miller, E. M. (1994a). Intelligence and brain myelination: A hypothesis, Personality and Individual Differences,17, 803-833.
Miller, E. M. (1994b). Paternal provisioning versus mate seeking in human populations, Personality and Individual Differences, 17:2, 227-255.
Miller, E. M. (1994c). The Relevance of group membership for personnel selection: A demonstration using Bayes theorem, Journal of Social, Political, and Economic Studies, 19:3, 323-359.
Miller, E. M. (1994d). Tracing the Genetic History of Modern Man. Mankind Quarterly, 35. 71-108.
Miller, E. M. (1995a). Environmental variability selects for large families only in special circumstances: Another objection to differential K theory, Personality and Individual Differences, 19:6, 903-918.
Miller, E. M. (1995b). Race, socioeconomic variables, and intelligence: A review and extension of the bell curve, Mankind Quarterly, 35:3, 267-291.
Miller, E. M. (1996a). The Evolution of Australian and Amerindian Intelligence, Mankind Quarterly, 37, 149-186.
Miller, E. M. (1996b). BackFire: A Review and Extension, Journal of Social, Political, and Economic Studies, 21, 477-491.
Miller, E. M. (1996c). Intelligence and myelination, Mensa Research Journal, 38, 6-54.
Miller, E. M. (1996d). Myopia and intelligence, Mensa Research Journal, 38, 55-75.
Miller, E. M. (1997a). Income, intelligence, social class, and fertility, Journal of Social, Political, and Economic Studies, Vol. 22 (Spring 1997) No 1, 95-117.
Miller, E. M. (1997b). "Out of Africa": Neanderthals and Caucasoids? Mankind Quarterly. 37:3, 231- .
Miller, E. M. (1997c). Race, intelligence, and income. In Leading Essays in Afro-American Studies, edited by Nikongo BaNikongo. Carolina Academic Press, 1997.
Mischel, W. & Metzer, R. (1962). Preference for delayed reward as a function of age, intelligence, and length of delay interval, Journal of Abnormal and Social Psychology, 64, 425-431.
Montalbano, W. D. (1995). Code of ethics given to fertility doctors. Times-Picayune, April 17, 2.
Pederson, N. L., Plomin, R., McClearn, G. E., & Friberg, L. (1988). Neuroticism, extraversion, and related traits in adult twins reared apart and together. Journal of Personality and Social Psychology, 55, 950-957.
Plomin, R., G. McClearn, D. Smith, P. Skuder, S. Vignetti, M. Chorney, K. Chorney, S. Kasarda, L. Thompson, D. Detterman, S. Petrill, J. Daniels, M. Owen, & P. McGuffin (1995). Allelic associations between 100 DNA markers and high versus low IQ, Intelligence, 21, 31-48.
Reed, T. et al. (1995). Lower cognitive performance in normal older adult male twins carrying the apolipoprotein E e4 allele, Archives of Neurology, 51, 1189-1192.
Reilly, P. R. (1991). The Surgical Solution: A History of Involuntary Sterilization in the United States. Baltimore: John Hopkins.
Rosner, M. & Belkin, M. (1987). Intelligence, education, and myopia in males. Archives of Opthalmology, 105 1508-1511.
Rowe, D. C. (1994). The Limits of Family Influence. New York: Guilford Press.
Rowe, D. C. & Osgood (1984). Sociological theories of deliquency and heredity: A reconsideration. American Sociological Review, 49, 526-540.
Rushton, J. P. (1980). Altruism, Socialization, and Society, Englewood Cliffs: Prentice Hall.
Rushton, J. P. (1995). Race, Evolution and Behavior: A Life History Perspective. New Brunswick: Transaction Publishers.
Rushton, J. P. & Ankney, C.D. (1996) Brain size and cognitive ability: Correlations with age, sex, social class, and race. Psychonomic Bulletin and Review, 3, 21-36.
Rushton, J. P. & Osborne, R. T. (1995). Genetic and environmental contributions to cranial capacity in black and white adolescents. Intelligence 20, 1-13.
Saetz, S. B. (1985). Eugenics and the Third Reich. The Eugenics Bulletin, Winter 1985, p. 1-31, found at the Future Generations website. www.eugenics.net
Scarr, S., & Weinberg, R. A. (1978). The influence of "family background" on intellectual attainment. American Sociological Review, 43, 674-692.
Scheper-Hughes (1992). Death Without Weeping: The Violence of Everyday Life in Brazil. Berkeley: University of California Press.
Seligman, D. (1992). A Question of Intelligence. New York: Birch Lane Press.
Skuder, P., Plomin, R., McClearn, G., Smith, D.,Vignetti, S., Chorney, M., Chorney, K., Kasarda, S., Thompson, L., Detterman, D., Petrill, S., Daniels, J., Owen, M., & McGuffin, P. (1995). A polymorphism in mitochondrial DNA associated with IQ? Intelligence, 21, 1-12.
Snyderman, M. and Rothman, S. (1988). The IQ Controversy, the Media and Public Policy. New Brunswick, Transaction Books.
Specter, M. (1997). After decades and many missteps, cloning success. New York Times, March 3, Sec. A, p.1.
Spitz, H. H. (1986). The Raising of Intelligence: A Selected History of Attempts to Raise Retarded Intelligence. Hillsdale, N. J.: Erlbaum.
Storfer, M. D. (1990). Intelligence and Giftedness, San Francisco: Jossey-Bass.
Sulloway, F. J. (1995). Birth order and evolutionary psychology: A meta-analytic overview. Psychological Inquiry, 6, 75-80.
Sulloway, F. J. (1996). Born to Rebel: How Sibling Rivalry Fosters Revolutionary Genius. Pantheon, NY.
Teasdale, T. W., Fuchs, J. & Goldschmidt, E. (1988). Degree of myopia in relation to intelligence and educational level. The Lancet, 1351-1353.
Tu, G. & Israel, Y. (1995). Alcohol consumption by Orientals in North America is predicted largely by a single gene. Behavior Genetics, 25, 59-65.
Van Court, M. (1983). Unwanted births and dysgenic reproduction in the United States. The Eugenics Bulletin, Spring, 1983, 8-16. Available at Future Generations website www.eugenics.net
Wickett, J. C., Vernon, P. A. & Lee, D. H. (1994). In vivo brain size, head perimeter, and intelligence in a sample of healthy adult females. Personality and Individual Differences, 16, 831-838.
Willerman, L., Schultz, R., Rutledge, J. N. & Bigler, E. D. (1991). In vivo brain size and intelligence. Intelligence, 15, 223-228.
Westman, J. C. (1994). Licensing Parents. New York: Insight Books.
Wilson, J. Q. & Herrnstein, R. J. (1985). Crime and Human Nature. New York: Simon & Schuster.