Despite warnings by moral conservatives, advances in genetics and reproductive technology have created the conditions for a consumer-driven mass eugenics industry. Like it or not, science is about to pose a slather of moral, ethical and societal dilemmas
A legal, social and biological revolution is taking place worldwide without much serious thinking of the consequences. Consider this: in Britain the House of Commons recently approved the use of “three-parent IVF” to remove defective mitochondrial DNA from babies.
Each year in Britain about 100 children are born with mutated mitochondrial DNA, resulting in about ten cases of fatal disease to the liver, nerves or heart. A new in vitro fertilisation (IVF) technique developed at the University of Newcastle allows doctors to replace a mother’s defective mitochondrial DNA with that of a healthy donor, presumably using pre-implantation sequencing and microscopic operation on the zygote. Mitochondrial DNA does not affect appearance, personality or intelligence, and it reduces kinship—genetic similarity—by only about 1 per cent. Still, the resulting child, though its nuclear DNA would come from its main parents, would have three parents.
Critics warned that this would set society off down a slippery slope to eugenics and “designer babies”. A government official, the “British Fertility Regulator”, replied to this warning with the observation that most people support the therapy. This was intended to assuage the concerns expressed. In fact it would seem to confirm them, since widespread support for a product or service indicates a readiness to adopt it. Sure enough, though there had been little public discussion in advance of the Commons debate, the new techniques were nonetheless approved by a large parliamentary majority. Australian scientists have since called for the British policy to be emulated.
This essay appears in the May, 2015, edition of Quadrant.
Click here to subscribe
Despite half a century of warnings by moral conservatives, advances in genetics and reproductive technology have created the conditions for a consumer-driven mass eugenics industry. Here is the Oxford dictionary definition of “Eugenics”: “the science of improving a population by controlled breeding to increase the occurrence of desirable heritable characteristics”. It has a bad historical reputation because authoritarian governments have denied civil liberties in the name of eugenics. But as we shall see, both the definition and the reputation of eugenics have been overtaken by advances in science, medicine and marketing. Eugenics has since reappeared in many countries in the form of voluntary genetics counselling—a medical service provided to help parents avoid genetic disorders in their children; and IVF has become a sizeable industry that offers parents the genetic screening of embryos and other eugenic choices.
Genetic improvement is becoming a market phenomenon—a situation discernible as long ago as the 1980s when Daniel Kevles, the leading historian of eugenics in the USA, quoted a biotechnology expert thus: “‘Human improvement’ is a fact of life, not because of the state … but because of consumer demand.”
The underlying reason why we can expect massive demand for eugenics services is the human misery caused by deleterious mutations as reported in stories about health and lifestyle. Beneficial mutations do occur, though rarely. When they do they enable adaptive mutations to spread throughout the population. But most evolution involves the sifting out of harmful mutations which occur in every generation. Most natural selection is like the Red Queen in Lewis Carroll’s Through the Looking Glass, always running in order to stay in the same place. The resulting balance was upset by the scientific and industrial revolutions. Prosperity, modern medicine and the welfare state caused the mutation load in humans to rapidly increase by relaxing the relentless winnowing of large families that made life “nasty, brutish and short”.
In the past, individuals could suffer death or disability due to small genetic defects, for example in their immune systems, for which modern medicine now routinely substitutes and which welfare cushions. But even modern medicine and welfare have their limits. W.D. Hamilton stated that when the misery resulting from mutations grows too great to bear—for medical, economic or humanitarian reasons—the load will be reduced, either naturally or artificially—painfully through elevated rates of mortality, or painlessly through eugenics.
Eugenics themes in the media
The public is reading and viewing a steady stream of information bearing on genetic improvement, priming a mass market for eugenics services. What follows is a small random sample of press clippings from the last two years. It indicates great advances in eugenics science and not much thinking about its social implications.
Any survey of eugenics themes in the media must discuss reports of animal breeding. One newspaper article in the Weekend Australian in August 2012 described how farmers breed animals, using the latest DNA assay techniques as well as traditional folk genetics. The article, “Breeders split on the best way to pick a champ”, reported the new computerised DNA method for choosing Merino studs for fineness and length of wool, worm resistance and fertility. Another report of animal breeding was an ABC television report of how Sydney’s Taronga Zoo imported a male gorilla, Kibali, from a French zoo. He was needed to replace the ageing silverback male and continue the breeding program. The zoo needed a western lowland gorilla, a subspecies or race facing extinction in its native Africa. The zoo aims to conserve population characteristics, a dimension of biodiversity. Kibali was chosen partly based on consideration of eugenics. His genetic profile showed that he had a low degree of genetic similarity (inbreeding) to the females at Taronga, reducing the risk of inbreeding depression. Also he came from a good family, because his mother showed excellent maternal behaviour. In addition he showed low aggression—dominant but not vicious.
A news report headed “Next-generation IVF makes perfect delivery” was published in July 2013. A baby was born in the USA using a new IVF technique that greatly improves the chances of successful implantation while substantially lowering the cost. Previously, IVF procedures suffered high rates of failure due to embryos having the wrong number of chromosomes. Only 30 per cent of implanted embryos result in full-term pregnancies. To compensate, doctors would implant several embryos, often leading to multiple conceptions. Chromosomal defects usually lead to an embryo spontaneously aborting, but when a baby does result it has genetic disorders, such as Down and Turner syndromes. In the case being reported, thirteen eggs from the thirty-six-year-old woman were fertilised in vitro, allowed to grow for five days, then some cells were screened to count the number of chromosomes. Only three embryos had the right number. Just one of these was implanted, resulting in a baby. The procedure—pre-implantation screening—doubles the pregnancy rate and halves the miscarriage rate. The monetary cost of next-generation IVF is reduced by the falling cost of genome sequencing combined with the greater reliability of implantation, allowing more patients to afford the procedure. The article noted that in Britain doctors are permitted to screen embryos only for the most serious genetic defects. However, in principle the technique, when expanded to screen genes as well as chromosomes, would allow much greater scope for eugenics. Parents could avoid many genetic predispositions in their children, such as that to cancer.
In January 2014 the Guardian Online reported that IVF babies suffer much higher rates of complications—born pre-term, stillborn, or dying within four weeks of birth. Doctors were unsure whether the cause was the IVF procedure or was related to the infertility that led women to seek IVF. Another finding indicates that the extra risk of pre-term birth does not arise with embryos kept frozen for some time before being thawed and implanted. Researchers speculate that this is due to the mother’s hormones having a chance to settle down following treatment to produce multiple eggs.
Further research in China supports this finding and adds a eugenics twist. Children resulting from frozen embryos were more socially adept than those implanted fresh after eggs were fertilised. The children also moved better, had superior communication skills and showed more independence. Allan Pacey, a fertility expert at the University of Sheffield, suggested that this was caused in part by the rigours of the thawing process. Not all embryos survive thawing, and perhaps those that do are “stronger”, he said. Perhaps freezing and thawing embryos is an inadvertent eugenics process, most successful with embryos having a low mutation load. This example reminds us that genes affect many characteristics including personality and social behaviour, not just physique and intelligence.
An August 2013 article, “Take the test or hope for the best?”, told the story of an Australian family carrying a rare mutation, CDH1, that bestows an 83 per cent risk of developing stomach cancer by mid-life. Modern sequencing techniques allow the faulty gene to be identified. So affected individuals could take what is a heroic preventive measure, namely removing the stomach. What was not discussed in the article was that screening of embryos would allow affected individuals to avoid passing the mutation on to their children (who otherwise have a 50 per cent chance of inheriting it). The article did note that thousands of medical genetic tests are now available in Australia, though in 2013 only fifteen such tests were covered by Medicare.
In 2011 almost 580,000 medical genetic tests were performed in Australia, 280 per cent higher than in 2006. Media coverage and medical advice are driving up the demand for genetic tests faster than the medical establishment’s capacity to provide them. Mass awareness was boosted by actress Angelina Jolie’s decision to have a double mastectomy following the discovery that she carried a mutant gene that causes breast cancer.
Another Australian report in January 2014, headed “DNA sequencing to be commonplace”, described the HiSeq X Ten sequencing system, purchased by the Garvan Institute of Medical Research in Sydney. This new machine is manufactured by US company Illumina, and can sequence up to 18,000 genomes per year at a cost of US$1000 each. That is one millionth the cost of sequencing the first genome. If this pace of development continues, the cost will continue to fall sharply. Professor John Mattick, head of the Garvan Institute, explained that whole-genome sequencing helps doctors prescribe drugs most compatible with the individual patient. It also allows identification of deleterious mutations. “Roughly 1 per cent of children suffer a significant genetic disease, but individually [the diseases are] rare and many are new mutations.” Already some parents of children with early onset diseases are having their genomes sequenced.  Identifying a mutation contributing to the disease not only aids diagnosis but “gives the parents the opportunity to avoid having further affected children”. Mattick stated that to take that step requires the parents’ genomes to be sequenced, to determine whether the mutation originated from them or occurred during reproduction.
Research reported in March 2014 found higher rates of gene defects in sperm as men age. Women pass on about fifteen new mutations to their children, but already by the age of twenty men typically pass on twenty mutations, by the age of forty this has risen to sixty-five, and by fifty-six the number has reached about 130. Children conceived by older fathers are at greater risk of autism, schizophrenia and other diseases. The trend for men to delay marriage is contributing to the overall mutation load. Theoretically a greater mutation load degrades all adaptations including immune resistance and general intelligence. 
All the reports reviewed above discussed genetics because eugenics relies heavily on knowledge about heredity. Genetics often evokes ideas about how to reduce disease or improve some characteristic. Genetical themes are ubiquitous in the media, in relation to family history, medicine and more.
Eugenics market takes off
Taken together, these reports indicate that “slippery slope” is an inadequate metaphor for the combustible mix of genomics and reproductive technology. A better metaphor would be “launching pad”. We have ignition.
Consider what is already happening in the large IVF market. Monash IVF, an Australian company with sales of $114 million, is positioning itself to compete with larger rivals by offering the latest technology for genetically screening embryos. The initial benefit is better pregnancy outcomes but as customers learn more of the science, they will inevitably wish to avoid deleterious mutations. Market-based eugenics will have taken off when the screening add-on becomes a major draw in its own right. There are early signs of this: for example a US firm, New Jersey Fertility Center, advertises pre-implantation genetic testing of embryos in conjunction with IVF. Such screening “allows for the selection of genetically normal embryos that can increase the chance of a successful pregnancy, decrease the risk of a miscarriage, minimise the risk of passing certain genetic diseases to your children and provide gender selection for family balancing”. (Emphasis added.)
The Center has six offices in the USA and caters to international patients. Eugenics services are becoming commonplace, for those who can afford them. In California, Stanford Fertility and Reproductive Medicine Center (SFRMC) freezes the eggs of women who expect to delay bearing children. This is associated with IVF because if a client should seek to have her eggs thawed and fertilised, that is done in a test tube (using sperm injection). When embryos are available, pre-implantation screening would be an option. Freezing eggs is becoming so popular that women in their twenties are beginning to use the procedure to insure themselves against infertility. The practice is also becoming popular in Britain. A poll of British and Danish women in 2014 found the following results: 20 per cent would freeze their eggs if the need arose, 90 per cent approve of others doing so for social reasons, and 99 per cent extend the same approval for medical purposes, such as preserving fertility in case of cancer.
Half of SFRMC clients work in the tech industry. Some women believe that the procedure gives them the option of a male-type career by slowing down the ticking clock. Savvy employers offer free egg freezing to attract or keep valuable female employees—a service that can cost US$20,000, which makes it unaffordable for many Americans. SFRMC also offers IVF and eugenics add-ons, such as a service for families with inherited cardiovascular disease. They offer genetic counselling to help construct a pedigree and thus identify risks. Clients can also purchase IVF with pre-implantation screening to choose only those embryos without the predisposition to heart problems.
In Australia, Monash IVF is looking to expand into Asian markets powered by its new screening technology. IVF has become big business largely due to demand from women who find it difficult to conceive after postponing childbearing. In 2013 9 per cent of Australian women had difficulty conceiving naturally. However, many had eggs of insufficient quality for use in IVF, with the result that demand is growing for egg donors. In the USA donors receive up to $10,000. In Australia donors are not paid, which contributes to a shortage of supply. Even so the lucrative Australian fertility services market was worth over $500 million in 2013. Demand continues to grow. The world market for IVF was US$9.3 billion in 2012, projected to grow to US$21.6 billion in 2020. And it has grown this large even though it has not provided many options for genetic improvement as yet.
Until the new British law, this market had grown largely under the radar of politics. But evidence has been mounting that demand for eugenics is putting pressure on legislators. A noteworthy article in 2003 by Tania Simoncelli, then a policy analyst at the International Center for Technology Assessment in Washington, decried the use of IVF with pre-implantation genetic diagnosis (screening) to select the sex of babies for non-medical purposes (as offered by the New Jersey Fertility Center). One reason is that unlike the old state-sponsored eugenics, the new type is “individual, market-based”. Consumer demand can be difficult to regulate—and the stronger the demand, the more difficult the regulation. As shown with prohibition of alcohol in the USA in the interwar period, with recreational drugs from the 1960s, and with prostitution since time immemorial, it is difficult to prevent wealthy consumers of goods or services from getting what they seek from willing providers.
The particular difficulty in regulating this new eugenics market was illustrated by a 2006 court case. The Italian Constitutional Court ruled that a couple using IVF could not use pre-implantation screening to eliminate the (high) risk that their children would suffer from thalassaemia, a blood disorder that greatly increases the risk of anaemia, loss of vigour, and in severe cases organ damage, stunted growth, liver disease, heart failure and even death. What the parents wanted was to implant those of their embryos that lacked the mutation that causes thalassaemia. The woman had already had two abortions after her foetuses were diagnosed with the condition and she wanted to avoid a repeat by using pre-implantation screening. After the court ruling, the couple considered travelling abroad to have IVF with genetic screening.
Their gynaecologist meanwhile reported strong demand for eugenics services. Between 1977 and 2004 his clinic in Sardinia had conducted prenatal screening of over 35,000 foetuses. When a significant genetic or chromosomal defect was found, 98 to 99 per cent of the couples involved chose abortion. What we see in this episode is a new social reality emerging: the rich travel to countries that allow IVF with pre-implantation screening or what the gynaecologist called “procreative tourism”; the poor choose abortion.
A note on terminology: Let me concede at once that from the standpoint of the Catholic Church, most evangelical Christians, and other moral conservatives, all of these couples are aborting their babies because they are discarding and destroying embryos some of which might otherwise be born and live lives. That is a moral stance deserving of respect which, as will become clear later, it will receive from me throughout this article. But I don’t share their view that an embryo at the earliest stages of pregnancy—a blastocyte of 100 cells—has the same personhood and human rights as a foetus, from about eight weeks. Indeed, I think one of the advantages of pre-implantation screening is that it reduces the frequency of pregnancy terminations at a stage when the foetus has clearly human characteristics, can feel pain, and might even survive outside the womb. On that basis I reserve the word abortion for terminations of foetuses, as in the above paragraph. I believe most people in Western societies share that view. It is true that majority opinion cannot settle a moral debate of this kind, and as the science of embryology develops we will all learn more and perhaps change our views.
Majority opinion does determine market demand, and the prospects and risks of consumer-driven eugenics are large and growing. In particular, procreative tourism could combine with the growing accessibility of IVF technology to make designer babies a reality. Bob Lanza, chief scientific officer of Advanced Cell Technology, an American biotechnology company, pioneered a cloning technique that can be copied by scientists with conventional IVF training. He warned that experimental eugenics is most likely in countries where cloning is not closely regulated.
Upside and downside
How will consumer demand drive this market for eugenics services? What types of government regulation might be needed? How effective would they be? Can it ever be appropriate for governments to initiate eugenics programs, as in Huxley’s Brave New World? And if they do, how do we protect civil liberties?
The first and most obvious benefit of genetic screening is the prevention of disease. The new genomics-based eugenics represents a significant advance on traditional methods. Consider the hypothetical case of a mutation that is only dangerous when inherited from both parents and is present in 1 per cent of the population. (In fact that is a high frequency for a deleterious mutation.) With random mating, only one in 10,000 people will inherit the mutation from both parents and only they will show ill effects. Even if all of these cases were prevented from reproducing, that would eliminate only one out of every 10,000 mutations each generation, which would be quite insufficient to counteract the accumulation of new mutations. That is why traditional eugenics aimed at reducing disease has little impact on the population as a whole. A small number of children are spared disease but the mutation itself remains at large, its damage almost undiminished. But the new IVF procedure can screen out selected mutations before they do harm. And it does so without abortion by terminating pregnancy at a very early stage. The procedure has room for improvement but is developing in the direction of a measured, targeted method that minimises collateral harm.
About 4000 genetic diseases affect humans. That results in 1 per cent of us being affected by one disorder or another. Many more people carry but do not express single copies of these mutations. Genetic diseases found around the world include cystic fibrosis, fabry disease, fragile X syndrome, Prader-Willi syndrome, spinal muscular atrophy and WHIM syndrome.
The situation is different in some small populations whose histories have resulted in much higher rates of some genetic diseases. For example, non-classical CAH, a type of congenital adrenal hyperplasia, causes developmental problems. It is suffered by one in 1000 people of European descent, which is considered a relatively high frequency for a serious disorder. However, its prevalence is much higher in certain populations—one in twenty-seven Ashkenazis, one in forty Hispanics, one in fifty Yugoslavs, and one in 300 Italians. Some ethnic groups at risk of genetic disorders are served by voluntary genetic screening programs that identify carriers and educate parents about preventive measures.
Some disorders are more common worldwide, such as schizophrenia, a devastating condition that is highly heritable. It afflicts about one in 300 people. About 80 per cent of the risk of contracting the disorder is due to mutated genes. Recent research indicates that schizophrenia consists of eight different disorders, each caused by a specific cluster of genes, which can be detected using screening technology.
Negative eugenics—or genetic intervention to ward off disease —can also keep down the mutation load in general. Mutations can reduce vigour and adaptiveness even when the effect is insufficient to be categorised as disease. As already mentioned, in all species the clock-like accumulation of mutations is cut down by the scythe of natural selection, but this process has been blunted in recent centuries by medical and welfare services. At the same time the supply of mutations has increased due to the increasing age of parents. On average fathers pass on seventy new mutations to their children, mothers fifteen. But the effect is greatest in parents who delay childbearing, in today’s world typically professionals.
Leading geneticists have supported the need to hold down the mutation load by artificial intervention. R.A. Fisher, a pioneer evolutionary theorist in the inter-war period, concluded that technically advanced civilisation is unsustainable without eugenics. W.D. Hamilton, another leading theorist of social genetics, argued that a rising mutation load means that humanity must choose between artificial and natural selection, the first relatively humane, the second not so at all. Supporting these views is a recent analysis of the data on mutation load and general intelligence by Michael Woodley. This analysis finds that increases in mutation load are driven by a combination of relaxed natural selection—the blunted scythe if you will—with the genetic errors originating largely in males. Woodley estimates that the growing mutation load is costing developed economies such as the UK and USA an average of 0.84 IQ points per decade, consistent with his estimate of the decline in general intelligence since the Victorian period.
Even if these dire predictions are true, there seems to be no pressing need to tackle the mutation load. Individuals and governments might someday be forced to make difficult decisions to counter the rising number of mutations. But that is no reason to sacrifice liberty or other values—at least for the present and perhaps never—if improvements in science and technology enable us to solve these problems in more acceptable ways. As the geneticist John Maynard Smith suggested in the 1980s, germline engineering—technology that corrects mutations in sperm, eggs or embryos, thus preventing them being passed onto children—would be the ultimate negative eugenics tool, allowing parents to wipe out their children’s mutation load in one fell swoop. That would be an escape from the logic of social Darwinism more permanent than medicine. It would no longer be true, as Shakespeare suggested in his twelfth sonnet, that “[N]othing ’gainst time’s scythe can make defence, save breed”, and that again would be without relying on abortion or the sacrifice of liberties,
The second main purpose of eugenics—or certainly of eugenicists—has traditionally been increasing human abilities. And that brings us onto the rocky territory of IQ. Francis Galton was spurred to invent eugenics by his view that in Britain those with the most productive characteristics of intelligence and personality were having fewer children than the least productive. Subsequent research confirmed part of this view by showing that in meritocratic societies wealth is correlated with ability.  In his review of the evidence for dysgenics, psychologist Richard Lynn shows that IQ has been negatively correlated with fertility in the USA and Europe since the beginning of the twentieth century when data were first collected. This coincides with the well-known “demographic transition”, which started about 1850 in Europe when the wealthy ceased having the largest families. Although IQ test results continue to rise, there is evidence that general intelligence in Europe is actually declining, as measured by reaction time, a measure of processing speed, and thus intelligence at the neurophysiological level.
If this is indeed a problem, it might be reduced by pre-implantation screening in the IVF market. As evolutionary psychologist Geoffrey Miller has stated, this could lead to substantial increases of intelligence within families that adopt it. That, however, would require the expansion of IVF services beyond the treatment of infertility. Initial expansion is being driven by demand for negative eugenics, in which parents choose an embryo with the lowest risk of genetic disease. Shortly before he died, Carl Djerassi, who developed the contraceptive pill, opined that improvements in IVF would, in time, induce most women to separate conception from sex. It will become normal, he thought, to use IVF to conceive because that allows screening of mutations; sex will be reserved for fun.
So when significant numbers of fertile women begin using IVF, we will know that market-based eugenics has left the launch pad. This could easily expand into positive eugenics where parents choose the best among healthy embryos in an attempt to give their children a better start in life. Most parents want their children to be not only healthy, but happy and successful. The surmise by James D. Watson, co-discoverer of the structure of DNA, is plausible: “Once you have a way in which you can improve our children, no one can stop it.” Watson wants parents to have access to genetic screening. That would aid negative eugenics but it would make the slope to positive eugenics more slippery.
Consider intelligence and our measurement of it. With whatever flaws it still has after refinement to deal with cultural biases and other factors, IQ remains the single best predictor of educational outcomes and is associated with several pro-social orientations including impulse restraint, reduced rates of criminality, and employment. Add that recent research indicates that children with a particular gene variant, together with lower thyroid hormone levels, are four times more likely to have an IQ under 85. An IQ at that level is not a disease or a defect. It is still in the normal range, but low and disadvantageous for the individual. It is more or less assumed by researchers that raising low IQ is a good thing. Parents are likely to agree. If a genetic test can predict this effect, and if hormone treatment in early childhood can improve it, what then? Other research is beginning to identify the many genes that contribute to intelligence.
Parents and their medical advisers might therefore not wish to rely on hormone treatment alone to avert a low IQ for their child. Effective hormone treatment is prone to error, needing accurate genetic diagnosis followed by delivery of the hormone on time at the right dose. On the other hand, imagine parents who opt for IVF as a means of avoiding the gene variant that lowers IQ. Ten eggs from the woman are fertilised in vitro by her husband. Seven of the resulting embryos are free of the variant. Of these, one has a 70 per cent risk of contracting schizophrenia. The parents decide to choose from the remaining six. How to choose among them? Should they just guess or should they make an attempt to actually improve their future child’s ability? In this imaginary case, the genetic tests are conducted overseas to circumvent anti-eugenics laws at home, which also free the couple to exercise other preferences. If tests show that two embryos have the genes likely to result in ten extra IQ points compared to the others, the same goal that motivated treatment in the first place would point to these embryos as the obvious choice. Attempting to select intelligence or any other trait among healthy embryos is what we mean by positive eugenics—and also what we mean by the slippery slope.
It should be said at once that the effects would not be as magical as they sometimes are in science fiction. Quantitative traits such as intelligence and personality cannot be increased forever. There are limits defined by the species architecture, if we assume (as we should) that limits to technology or parental choice prevent eugenics from producing non-human children. Initial gains are likely to be rapid but will then slow down as traits approach their upper limits. Nonetheless the great differences between individuals in the world today show that considerable room exists for changing bodies and brains.
So far we have been examining eugenics from the standpoint of how it might affect individuals and families. But what about their social benefits and costs? What would be the consequences to society of market-driven eugenics? That will depend on which types of eugenics—negative and positive—are adopted, and how widely. The following table shows four scenarios of how eugenics could spread. In scenarios A and B a small minority of citizens adopts negative or positive eugenics; in scenarios C and D a large majority of citizens do the same. How might the four scenarios work out?
Table 1. Four scenarios of future eugenics.
The four scenarios promise different social benefits and costs.
A. A minority of citizens adopt negative eugenics. Let us imagine that two types of negative eugenics have been identified: first, eliminating one or more of the 4000 mutations that cause genetic disease in about 1 per cent of the population; second, reducing the backlog of mutations which, though not amounting to a disease, together reduce physiological or psychological efficiency among a majority of the population.
(i) Eliminating genetic disease in families has an equalising effect, not a privileging one. An exception could arise if only a minority of families facing genetic disease availed themselves of eugenics services. In that situation inequality would increase between those families and similarly afflicted families that did not. That might cause resentment and be called unfair. However, as it would affect less than 1 per cent of the population, and as the privileged families would not gain an advantage over the other 99 per cent, the inequality would not be socially destabilising.
(ii) Reducing the mutation load would potentially benefit a much greater proportion of the population, perhaps all of it. If only a small minority could afford the procedure needed to reduce the overall number of mutations in their children, that would provide some benefit, though one hard to quantify. But the benefit would be broad within affected individuals, improving immune resistance, vigour, intelligence, mental health and more. This effect is likely to be small in each generation. If so, it would be a modest exaggeration of existing socio-economic inequality, insufficient to be socially destabilising.
In both types of minority-negative eugenics, moreover, any negative impacts could be remedied by broadening access.
B. A minority of citizens adopt positive eugenics. This would be less benign. If a small minority of the population begins choosing embryos not only for health but for desired characteristics such as intelligence, creativity and vigour, there would be costs as well as benefits. Bad choices are possible. With nature no longer at the tiller, parents could take a course with evil consequences for their children, perhaps due to scientific error, fads, gender bias or perverse motives. Government regulation might prevent some of these outcomes, or outlaw positive eugenics altogether. But if the perceived benefits were large enough—and they would be—wealthy clients would probably be able to find the necessary services overseas. Should that happen, the main cost of minority-positive eugenics is likely to arise from its success, children who are not quite “demi-gods” but strikingly intelligent, athletic, vigorous or attractive. The development of a eugenic caste is likely to degrade social cohesion and democracy.
Positive eugenics is nonetheless proposed by some of the most influential contemporary advocates for gene improvement. Julian Savulescu, professor of bioethics at Oxford University, argues that parents should be free to choose embryos that will not only give the children the best possible health but the most fulfilling life. It is morally wrong, he thinks, to limit reproductive choices. He explicitly approves positive eugenics, maintaining that parents should choose the “best children”. Savulescu and his doctoral supervisor Peter Singer do not perceive the danger of a eugenic caste because, like many mainstream sociologists, they deny biological influences on class differences.
Another enthusiast for positive eugenics who overlooks social consequences is George Church, a geneticist at Harvard and MIT and a biotech entrepreneur. Church maintains that “We’re well beyond Darwinian limitations to evolution. Evolution right now is in the marketplace.” His projections of germline engineering—adding or deleting genetic code as if editing computer code and then reproducing those changes in children—have aroused concern about inequality. Israeli historian Noah Harari, in his book Sapiens, draws on Church’s ideas to warn about the ossification of class differences. Harari suggests, “In the 21st century, there is a real possibility of creating biological castes, with real biological differences between rich and poor … The end result could be speciation.” (Speciation occurs when populations become so different that they can no longer breed together to produce fertile offspring.) Class differences will become exaggerated, Harari argues, because the rich will always have first access to the latest genetic or mechanical enhancements.
A more basic objection to Church’s vision is its over-confidence. Manipulating the germline to remove defective mutations would be beneficial; but adding new gene variants—invented or taken from other species—would be reckless. The simplest downside would be ill health; the most complex would affect social behaviour two or three decades later, for example by disrupting social bonds. Significant changes to appearance or behaviour could reduce the sense of kinship between designed children and their parents and fellow citizens. Human ties could fray due to ethno-centrism and species-centrism. If government regulation can achieve anything in this area, it should concentrate on preventing scientific arrogance being made flesh.
Harari’s concern about class differences in the uptake of positive eugenics is based only on differences in wealth. Behavioural differences could add to the disruption. Initially and perhaps for several generations, eugenics technology will be adopted by those parents who already invest most intensely in their children, in arranging the best education and medical care they can afford, who are far-sighted, ambitious and self-sacrificial for their offspring beyond the ken of most parents. In behavioural biology this corresponds to a slower “life history strategy”, meaning that parental investment and its results are more intense and produce reproductive payoffs over longer time periods. Slow life strategists are typically better educated, have their first child later than usual, have greater impulse control, lower rates of violence and crime, low rates of divorce and single parenthood. Except for those whose religion forbids it, these parents are likely to be the first to adopt proven eugenics technologies, negative and positive. As socio-economic class is correlated with a slow life history, eugenics can be expected to accentuate class differences. Ethnic differences could also be exaggerated. If so, the costs and tensions of diversity already evident in multicultural societies will grow. Popular demand to redistribute resources from rich to poor could intensify as inequalities of wealth rise; at the same time resistance to redistribution could stiffen because welfare is most generous within relatively homogeneous societies with low social barriers, not those fractured by competing castes.
Those willing and able to adopt positive eugenics could minimise “regression to the mean”, which normally causes children to be more average than their parents. Brilliant captains of industry and finance who amass fortunes have not been able to prevent descendants losing some competitive edge of intellect and character. It is not for lack of trying. Since about 1880 wealthy families have, on average, reduced family size the better to invest heavily in each child’s education and status. At the same time they have delayed childbearing to promote professional careers, increasing resources and status but greatly increasing the number of mutations passed onto children. The likely effect has been to accelerate regression to the mean. Economist Gregory Clark, who studies evolutionary effects on class structure, argues that regression “exercise[s] a death grip on dynastic ambitions”. Negative eugenics might slow this regression but it would not prevent it. Positive eugenics would give the kiss of immortality to wealthy lineages because it would allow parents to choose offspring whose talents are greater than chance would allow.
Extreme inequality among individuals lowers social cohesion. This effect is multiplied when differences in wealth or status affect whole groups, such as religions or ethnicities. With regard to caste inequality, the best-known example is slavery, a group hierarchy imposed by conquest and discriminatory laws. A different example, one that approximates the scenario of voluntary castes, has been middleman ethnic trading communities, in which traders belong to a minority ethnic group living outside its homeland. Their shared group identities establish greater trust and therefore allow for efficient market exchanges with minimal cheating. In-group identity is maintained by erecting barriers to marrying outside the ethnic group, an exclusivity that also helps retain an advantage in business skills over many generations. Examples are Jews in Medieval Europe, Chinese in South-East Asia, Armenians in the Ottoman empire until the First World War, Indians in West Africa until the 1970s, and Germans in Eastern Europe until the Second World War. Because of their economic efficiencies, these trading networks have repeatedly increased inequality.
To take just one example, ethnic Chinese in Indonesia and the Philippines, though just 1 per cent of the population, own about 70 per cent of the corporate economy and have been the objects of ill feeling on the part of the ethnic Malay majorities. Competition for resources by ethnic groups and the resulting stratification have been responsible for some of the bitterest conflicts associated with ethno-religious heterogeneity around the world.
A eugenic elite would marry in. It would, in effect, reproduce strictly within its class, either by choosing mates who were also the result of eugenics or by using embryo selection. As Herrnstein and Murray showed in The Bell Curve, the effect of assortative marriage alone, without eugenic selection, can be significant when it involves heritable characteristics such as height and IQ. The anthropologist Henry Harpending recently modelled the Herrnstein–Murray scenario, showing that assortment can have a dramatic effect in just one generation. The model shows that heritable group averages diverge when a minority class constituting the top 10 per cent of the population assorts (marries others who share a characteristic). The model predicts an average IQ difference of 30 points, sufficient to allow the eugenic class to dominate the professions and practise long-term dynastic strategies of wealth accumulation and influence.
The result would be wealth and status almost set in concrete, an inflexibility likely to result in social conflict because class lines would harden as the rich got ever richer. Dynasties would no longer spontaneously dissolve but persist down the generations unless their reproductive strategy was curtailed by government edict or revolution. Because the dynasties would depend on careful breeding, there would be an extra payoff from choosing mates who shared the eugenic culture and inheritance. From the perspective of democratic values, exclusive elite eugenics would be especially objectionable because it would add the insult of actual superiority to the injury of aristocratic privilege. Such an elite would have a vital interest in suppressing democracy to avoid redistributive policies. Their efforts to do so would be aided by their feelings of alienation from the masses with which they would have little social contact. They would find it adaptive to view the majority coldly, instrumentally and defensively.
A minority eugenic caste would be a dagger in the heart of something Westerners take for granted—a unified democratic community with a large degree of social mobility. For that reason it would be wise to outlaw or strictly regulate minority-positive eugenics. As already stated, that could prove difficult. Technically there is no great divide between negative and positive eugenics, and there is nothing inherently perverse about wanting one’s children to have a touch of the demi-god. If prevention proves impracticable, an alternative to defeating the resulting exclusivity might be to universalise it. If the lower orders cannot beat a eugenic upper caste, they might vote to join it by demanding that government provide eugenics services as an essential component of the welfare state. (I speculate on the social consequences of “majority-positive” eugenics presently.)
C. A majority of citizens adopt negative eugenics. This scenario is the surest way to a beneficial outcome, with only moderate risk. Negative eugenics that prevented genetic disease would greatly improve the lives of the 1 per cent of the population affected. A wider though slighter benefit would accrue if most families had their mutation loads reduced.
Though affecting only a small minority, genetic disease exerts a financial strain on society. As long ago as 2002 just one condition, schizophrenia, cost the USA $63 billion in medical expenses and welfare, equivalent to $77 billion based on 2014 GDP. This can be used to roughly cost genetic disease for the US economy at $308 billion, which is not large compared to the gross domestic product of a $16 trillion economy but is large compared to government outlays of about $1 trillion. To the extent that it would alleviate burdens on the economy and on taxation, negative eugenics constitutes a public good, a service that benefits society as a whole.
Eliminating some genetic diseases might carry costs. This is indicated by the fact that some conditions occur at levels much too high to be explained by chance mutation. This is sometimes explained by a gene variant having beneficial as well as harmful effects. There are some well-known examples of genes with multiple effects, or pleiotropy.
To take one example, sickle cell anaemia causes premature death and afflicts 2 per cent of Nigerian newborns, with similar rates affecting other sub-Saharan African populations. Some parts of India are also affected. Experts maintain that the mutation responsible for the condition has been naturally selected because an individual carrying just one copy can better resist malaria. Anaemia affects only those who inherit the mutation from both parents. When both parents are healthy carriers, on average half their children will receive one copy and therefore benefit from immunity, a quarter will be unprotected, and a quarter will suffer from anaemia. Without modern anti-malaria drugs, a eugenics program that eliminated the sickle cell mutation would result in greater contagion by malaria.
An analogous situation might exist with some mental conditions, such as schizophrenia and autism, which could be outlier expressions of gene variants with beneficial single-copy effects, such as increasing intelligence or creativity. Without sufficient knowledge of human genetics, a society-wide eugenics program could, by reducing human biodiversity, dull a vital spark. That possibility is unlikely to prevent parents putting the welfare of their children first, even if they know the larger consequences.
D. A majority of citizens adopt positive eugenics. In Eugenics: A Reassessment Richard Lynn argues that enhancing children is good and foresees developments in genetics and IVF making functional traits available for genetic manipulation. In his view positive eugenics will be adopted by the great majority of parents. The gains would be sufficient to give designer babies a tremendous head start, not only in cognition but also in personality and vigour. Lynn does not envisage a small elite caste using eugenics to lord it over the unselected masses because he sees eugenics becoming the norm. Nevertheless, even if most adopt embryo selection, there will still be a growing social divide with those who do not. An average IQ gap of 55 points with attendant personality changes would be more than sufficient to cause dramatic cultural differences and polarisation.
George Church thinks that IVF using germline engineering will result in differences so great that the two populations constitute different species. Lynn does not go so far but expects that naturally-reproducing people in majority-positive eugenic societies would occupy the lower socio-economic niches, often unemployed and unemployable. The resulting welfare burden would come to be seen as a genetic problem. But Lynn does not consider the effect of differences in birth rates. If present trends continue, parents of the eugenic class will have fewer children than the non-eugenic, threatening to reduce their proportion of the population and perhaps leading to populist reaction and defensive counter-measures. Again, this indicates social division and perhaps conflict.
Admittedly the benefits from majority-positive eugenics would be greater than those from majority-negative. This would stand to improve employment rates and thus reduce welfare, boost creativity both technical and cultural, and reduce inequality within the eugenic population, thereby raising political stability.
One benefit from widespread positive eugenics would be a greater prevalence of geniuses. Genius of intellect or character benefits the whole society, whether through scientific, technical, cultural or political innovation. That makes ultra-high intelligence a public good. Turning points in civilisation were based on macro-innovations—ideas and inventions of great novelty and far-reaching impact—produced by very clever individuals. These include the plough, writing, astronomical navigation, the steam engine and the semi-conductor. Creativity of this magnitude stimulates the economy, improves life and helps society adapt to challenges.
Positive eugenics would increase the number of geniuses because abilities of cognition and personality are distributed in a bell curve. A slight increase in the average greatly increases the proportion of gifted individuals. For example, increasing the average IQ from 100 to 105 would increase the number of individuals with IQ over 160 almost four-fold. (Recall that Woodley estimates a loss of 8.4 IQ points per century due to rising mutation load alone.) Increasing the average to 120, well within what Lynn sees as feasible within two generations, would increase the number of 160+ individuals about 125-fold.
As the innovations produced by highly intelligent people are public goods, it would seem prudent for representative governments to allow the reproductive choices that produce more of them. If most citizens adopted eugenic reproduction, the benefits of accelerated innovation could be gained without allowing an upper caste to develop. Further reducing the political risk is the altruistic bent of many gifted individuals. Historical research indicates that the ultra-intelligent often have had few or no children, even in earlier centuries when ability normally correlated with fertility. At the same time they enriched industry and culture and increased the fitness of their nations.
There might be other benefits of a general rise in cognitive ability. Evidence assembled by Finnish sociologist Tatu Vanhanen indicates that rising average intelligence promotes socio-economic equality and thus democracy. This effect is not certain. China is a rather large exception to the rule because it has the highest IQ of any large population but has never been democratic. But even a limited effect as Vanhanen suggests could mean that eugenic societies would trend towards relative egalitarianism and democracy.
The second part of this essay will examine the sometimes imprudent visions of gene improvement being disseminated by academic experts and discuss the possibilities and ethical and political dangers of government-led eugenics.
Frank Salter is an urban anthropologist and ethologist who studies organisations and society using the methods and concepts of behavioural biology. His books include On Genetic Interests and Emotions in Command. A footnoted version of this article appears on Quadrant Online. The second part of this article will appear shortly.
 “Three-parent babies to be born in Britain as MPs say yes to law change”, Telegraph (London), 3 February 2015. http://www.telegraph.co.uk/news/science/science-news/11387179/Three-parent-babies-to-be-born-in-Britain-as-MPs-say-yes-to-law-change.html
 “Britain’s three-parent IVF decision raises hopes in Australia”, The Australian, 5 Feb. 2015, p. 3.
 Burcham, P. (2013). “Genetic counselling and the death of medical compassion.” Quadrant, September. https://quadrant.org.au/magazine/2013/09/genetic-counselling-and-the-death-of-medical-compassion/.
 Biotechnology expert quoted by Daniel Kevles (1995/1985). In the name of eugenics: Genetics and the uses of human heredity. Cambridge, MA, Harvard University Press, p. x.
 Ridley, M. (1993). The red queen: Sex and the evolution of human nature. New York, Viking.
 Hamilton, W. D. (1996/1971). Selection of selfish and altruistic behaviour in some extreme models. Narrow roads of gene land. Vol. 1: Evolution of social behaviour. W. D. Hamilton. Oxford, W. H. Freeman. 97: 198-227, p. 193.
Jones, S. (1992). The evolutionary future of humankind. The Cambridge encyclopedia of human evolution. S. Jones, R. D. Martin, D. R. Pilbeam and S. Bunney. Cambridge, Cambridge University Press: 439-45.
 Sue Neales (2012). “Breeders split on best way to pick a champ”, Weekend Australian, 11-12 August, p. 15.
 Wildlife at the Zoo: Episode 5—Silverback Gorilla. ABC 1. 16 May 2012. http://www.abc.net.au/tv/wildlifeatthezoo/episodes/ep05.htm, accessed 18 May 2012.
 “Next-generation IVF makes perfect delivery”, The Australian, 9 July 2013, p. 7. The same event was reported by The Guardian Online: Ian Sample, “IVF baby born using revolutionary genetic-screening process”, 8 July 2013. http://www.theguardian.com/science/2013/jul/07/ivf-baby-born-genetic-screening, accessed 10 July 2013.
 http://www.theguardian.com/society/2014/jan/08/ivf-babies-risk-complications-study, accessed 12 March 2014.
 Kat Lay (2014). “Children from frozen embryos ‘more sociable’”, The Australian, 23 October, p. 3. Reprinted from the (London) Times. http://www.theaustralian.com.au/news/world/children-from-frozen-embryos-more-sociable/story-fnb64oi6-1227099092904, accessed 23 Oct. 2014.
 Kate Legge (2013). “Take the test or hope for the best?” Weekend Australian Magazine, 17-18 August, pp. 10-15.
 For example: Amy Dockser Marcus and Leigh Dayton 92012). “Gene is out of the bottle”. Weekend Australian, 19-20 May, Health section, p. 7.
 John Ross (2014). “DNA sequencing to be commonplace”, The Australian, 16 Jan., p. 5.
 John Ross (2014). “The genomics revolution”, The Australian, 17 Jan., p. 9.
 “Older dads and ugly facts” The Australian, 24 March 2014, p. 18. Reprinted from The Sunday Times.
 Woodley, M. A. (2014 in press). “The gruesome twosome: Estimating dysgenic reductions in g due to both selection and mutation accumulation.” Personality and Individual Differences.
 Jessica Gardner (2014). “Monash eyes small clinics and Asian leap”, The Australian Financial Review, 29 August, p. 19.
 http://www.ivfnj.com/preimplantation-genetic-diagnosis-pgd/, accessed 28 Aug. 2014.
 http://www.froedtert.com/fertility/preserving-fertility/freezing-eggs, accessed 20 Oct. 2014.
 Rhys Blakely (2014). “‘I feel more like a guy after boss froze my eggs’”, The Australian, 17 Oct., p. 10. Republished from The Times. http://www.theaustralian.com.au/news/world/i-feel-more-like-a-guy-after-employer-froze-my-eggs/story-fnb64oi6-1227092978026?login=1
 Laura Donnelly and agencies (2014). “Women support putting eggs ‘on ice’ for social reasons”, Telegraph [London], 1 July. http://www.telegraph.co.uk/health/healthnews/10935620/Women-support-putting-eggs-on-ice-for-social-reasons.html.
“One option that reduces the chances of passing on the hereditary heart condition is called preimplantation genetic diagnosis (PGD). Embryos are created through in vitro fertilization (IVF) prior to pregnancy and genetic testing is used to select embryos that do not have the predisposition to heart problems. PGD is only an option if the genetic mutation causing the heart condition in your family has been found through genetic testing.”
 SBS Television News, 10 March 2014.
 “Monash IVF prepares for sharemarket float”, Weekend Australian, 8-9 March 2014, p. 31.
 Tania Simoncelli (2003). “Pre-implantation genetic diagnosis and selection: From disease prevention to customized conception”, Different Takes, Spring. http://genetics.live.radicaldesigns.org/downloads/200303_difftakes_simoncelli.pdf, accessed 25 Feb. 2014.
 Fabio Turone (2006). “Italian court upholds ban on pre-implantation diagnosis”, British medic al Journal, 4(333): p. 934. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1633778/#!po=83.3333, accessed 25 Feb. 2014.
 Giovanni Monni (2006). [Article in] Fetal Diagnosis and Therapy 21: 348-54.
 Hannah Devlin (2014). “Adult skin used to clone embryo”, Weekend Australian, 19-20 April, p. 10.
 Not counting cancers. GeneCards: The Human Gene Compendium, http://www.genecards.org/cgi-bin/listdiseasecards.pl?type=full, accessed 4 September 2014.
 Genetic Disease Foundation, http://www.geneticdiseasefoundation.org/genetic-diseases/, accessed 4 September 2014.
 Higher rates of mutation can result from population bottlenecks, genetic drift, local selection conditions and the founder effect.
 (2014). “Congenital adrenal hyperplasia”, BMJ Best Practice. http://bestpractice.bmj.com/best-practice/monograph/699/basics/epidemiology.html, accessed 7 Oct. 2014.
 For example, the “Program for Jewish Genetic Health” is run by the Albert Einstein College of Medicine of Yeshiva University, New York. http://www.einstein.yu.edu/centers/jewish-genetic-health/, accessed 11 September 2014.
 Arnedo, J., D. M. Svrakic, et al. (2014). “Uncovering the hidden risk architecture of the schizophrenias: Confirmation in three independent genome-wide association studies.” American Journal of Psychiatry. http://ajp.psychiatryonline.org/article.aspx?articleID=1906049&resultClick=3
 Fisher, R. A. (1999/1930). The genetical theory of natural selection. A complete variorum edition. Oxford, Oxford University Press.
 Hamilton, W. D. (1969/1996). Population control. Narrow roads of gene land. Vol. 1: Evolution of social behaviour. W. D. Hamilton. Oxford, W. H. Freeman. 97: 196 [originally in New Scientist 144 (120 Oct.) 1969, pp. 1260-1961].
Hamilton, W. D. (2000). “A review of Dysgenics: Genetic deterioration in modern populations.” Annals of Human Genetics 64: 363-74.
 Woodley, M. A. (2014 in press). “How fragile is our intellect? Estimating losses in general intelligence due to both selection and mutation accumulation”, Personality and Individual Differences.
 Maynard Smith is quoted in discussion with Bill Hamilton, in Hamilton, W. D. (2001). The hospitals are coming. Narrow roads of gene land II. W. D. Hamilton. Oxford, Oxford University Press. 2: 449-510, p. 456.
 William Shakespeare, Sonnet XII, quoted by Hamilton, ibid., p. 511.
 This has been seen by some as an empirical problem for Darwinian theory, in which competition to reproduce should maintain a correlation between wealth and fitness.
Vining, D. R. (1986). “Social versus reproductive success: The central theoretical problem of human sociobiology.” The Behavioral and Brain Sciences 9: 167-216.
 Lynn, R. (1996). Dysgenics. Genetic deterioration in modern populations. Westport, CT, Praeger Publishers.
Lynn, R. and M. Van Court (2004). “New evidence of dysgenic fertility for intelligence in the United States.” Intelligence 32(2): 193-201.
 Woodley, M. A., J. te Nijenhuis, et al. (2014). “Is there a dysgenic secular trend towards slowing simple reaction time? Responding to a quartet of critical commentaries.” Intelligence 46: 131-47.
“Sex will soon be just for fun not babies, says father of the Pill”, The Telegraph (London), 9 Nov. 2014. http://www.telegraph.co.uk/news/health/news/11217750/Sex-will-soon-be-just-for-fun-not-babies-says-father-of-the-Pill.html
 The full quote is: “It seems unfair that some people don’t get the same opportunity. Once you have a way in which you can improve our children, no one can stop it. It would be stupid not to use it because someone else will. Those parents who enhance their children, then their children are going to be the ones who dominate the world…” Watson interviewed in the television documentary DNA (2003). Produced by Brian Brunius, directred by Ian Duncan, Carlo Massarella and David Glover, narrated by Jeff Goldblum. http://www.imdb.com/title/tt0903750/fullcredits?ref_=tt_cl_sm#cast, accessed 15 September 2014.
 Greenman, J. E. (2005). “Watson promotes preventative eugenics.” The Harvard Crimson. 7 March. http://www.thecrimson.com/article/2005/3/7/watson-promotes-preventative-eugenics-lecturing-to/
 http://www.endocrinology.org/press/pressreleases/2014-03-24_GeneticScreeningChildrenAtRiskLowIQ.pdf, accessed 15 September 2014.
 Rietveld, C. A., T. Esko, et al. (2014). “Common genetic variants associated with cognitive performance identified using the proxy-phenotype method.” Proceedings of the National Academy of Sciences. September 8, http://www.pnas.org/content/early/2014/09/05/1404623111.abstract.
 Woodley, M. A. (2014 in press). “How fragile is our intellect? Estimating decline in general intelligence based on selection and mutation.” Personality and Individual Differences.
 Julian Savulescu blog: http://blog.practicalethics.ox.ac.uk/2011/01/nazi-eugenics-returns-to-germany-the-paradox-of-eugenics/, accessed 2 Oct. 2014.
 “Welcome to my genome”, Technology Quarterly, Q3 2014. http://www.economist.com/news/technology-quarterly/21615029-george-church-genetics-pioneer-whose-research-spans-treating-diseases-altering, accessed 15 September 2014.
 http://www.theguardian.com/science/2014/sep/05/body-upgrades-only-for-rich, accessed 15 September 2014.
 Vanhanen, T. (2012). Ethnic conflicts: Their biological roots in ethnic nepotism. London, Ulster Institute for Social Research.
 Figueredo, A. J., G. Vasquez, et al. (2006). “Consilience and life history theory: From genes to brain to reproductive strategy.” Developmental Review 26: 243-75.
Figueredo, A. J., T. C. D. Baca, and M. A. Woodley (2013). “The measurement of human life history strategy.” Personality and Individual Differences 55(3): 251-5.
 Salter, F. K., Ed. (2004). Welfare, ethnicity, & altruism: New data & evolutionary theory. London, Frank Cass.
 Salter, F. K. (2008). Class mobility, environment, and genes: A Darwinian conflict analysis. The new evolutionary social science: Human nature, social behavior, and social change. H.-J. Niedenzu, T. Meleghy and P. Meyer. Boulder, Colorado, Paradigm: 159-71.
 Clark, G. (2014). The son also rises: Surnames and the history of social mobility. Princeton, Princeton University Press, p. 280. Samples available at: http://books.google.com.au/books?hl=en&lr=&id=w3t4AgAAQBAJ&oi=fnd&pg=PP1&dq=Clark+the+son+also+rises&ots=8EV1xEnJ9L&sig=Ua8LBVYpmslxSHNU1n_2iEdnsbQ#v=onepage&q&f=false
 With regard to inequality among individuals, see Wilkinson, R. and K. Pickett (2009). The spirit level: Why greater equality makes societies stronger. New York, Bloomsbury Press.
 Salter, F. K. (2008). “Genes and homogeneous trading groups: A comment on Janet Landa’s target paper.” Journal of Bioeconomics 10: 303-06.
Salter, F. K. (2008). Class mobility, environment, and genes: A Darwinian conflict analysis. The new evolutionary social science: Human nature, social behavior, and social change. H.-J. Niedenzu, T. Meleghy and P. Meyer. Boulder, Colorado, Paradigm: 159-71.
 Chua, A. (2003). World on fire: How exporting free market democracy breeds ethnic hatred and global instability. Doubleday & Company.
 Bonacich, E. (1973). “A theory of middleman minorities.” American Sociological Review 38: 583-94.
Vanhanen, T. (2012). Ethnic conflicts: Their biological roots in ethnic nepotism. London, Ulster Institute for Social Research.
 Harpending, H. and G. Cochran (2015-in press). Assortative mating, class, and caste. The evolution of sexuality. T. K. Shackelford and R. D. Hansen, Springer International Publishing Switzerland, Figure 3.
http://www.multpl.com/us-gdp-inflation-adjusted/table, accessed 7 Oct. 2014.
 The 4,000 known genetic diseases affect about 1 per cent of the population, perhaps not including schizophrenia. The latter affects 1 in 300 of the U.S. population. It is an economically damaging condition. But assuming that all diseases incur the same cost as schizophrenia, the total cost in 2009 dollars is about 4 x $77 billion = $308 billion.
 Cochran, G., J. Hardy, H. Harpending (2006). “Natural history of Ashkenazi intelligence.” Journal of Biosocial Science 38: 659-93.
 Richard Lynn (2001). Eugenics: A reassessment. Westport, CN, Praeger, p. 288.
 Harpending, H. and G. Cochran (2015— in press). Assortative mating, class, and caste. The evolution of sexuality. T. K. Shackelford and R. D. Hansen, Springer International Publishing Switzerland.
 Murray, C. (2004/2003). Human accomplishment: The Pursuit of excellence in the arts and sciences, 800 B.C. to 1950. New York, Harper Perennial.
 Calculated using the normal curve calculator at http://www.measuringusability.com/normal_curve.php, setting the standard deviation at 15.
 Simonton, D. K. (2003). Exceptional creativity across the life span: The emergence and manifestation of creative genius. The international handbook of innovation. L. V. Shavinina. New York, Pergamon: 293-308.
 Vanhanen, T. (2009). The limits of democratization: Climate, intelligence, and resource distribution. Augusta, Georgia, Washington Summit Publishers.