Peter Singer, ‘A Darwinian Left: Politics, Evolution and Cooperation’, London: Weidenfeld & Nicolson 1999.
Social Darwinism is dead.
The idea that charity, welfare and medical treatment ought to be withheld from the poor, the destitute and the seriously ill so that they perish in accordance with the process of natural selection and hence facilitate further evolutionary progress survives only as a straw man sometimes attributed to conservatives by leftists in order to discredit them, and a form of guilt by association sometimes invoked by creationists in order to discredit the theory of evolution.
Of course, as Dawkins also emphasizes, we have evolved through kin selection to be altruistic towards our close biological relatives. However, this arguably only reinforces conservatives’ faith in the family, and their concerns regarding the effects of family breakdown and substitute parents.
Finally, research on sex differences surely suggests that at least some traditional gender roles – e.g. women’s role in caring for young children, and men’s role in fighting wars – do indeed have a biological basis, and also that patriarchy and the gender pay gap may be an inevitable result of innate psychological differences between the sexes.
Against this, however, moral philosopher and famed animal liberation activist Peter Singer, in ‘A Darwinian Left’, seeks to reclaim Darwin, and evolutionary psychology, for the Left. His attempt is not entirely successful.
The Naturalistic Fallacy
At least since David Hume, it has an article of faith among most philosophers that one cannot derive values from facts. To do otherwise is to commit what some philosophers refer to as the naturalistic fallacy.
Edward O Wilson, in Sociobiology: The New Synthesis was widely accused of committing the naturalistic fallacy, by attempting to derive moral values form facts. However, those evolutionary psychologists who followed in his stead have generally taken a very different line.
Indeed, recognition that the naturalistic fallacy is indeed a fallacy has proven very useful to evolutionary psychologists, since it has enabled them investigate the possible evolutionary functions of such morally questionable (or indeed downright morally reprehensible) behaviours as infidelity, rape, warfare and child abuse while at the same time denying that they are somehow thereby providing a justification for the behaviours in question.
Singer, like most evolutionary psychologists, also reiterates the sacrosanct inviolability of the fact-value dichotomy.
Thus, in attempting to construct his ‘Darwinian Left’, Singer does not attempt to use Darwinism in order to provide a justification or ultimate rationale for leftist egalitarianism. Rather, he simply takes it for granted that equality is a good thing and worth striving for, and indeed implicitly assumes that his readers will agree.
His aim, then, is not to argue that socialism is demanded by a Darwinian worldview, but rather simply that it is compatible with such a worldview and not contradicted by it.
Thus, he takes leftist ideals as his starting-point, and attempts to argue only that accepting the Darwinian worldview should not cause one to abandon these ideals as either undesirable or unachievable.
But if we accept that the naturalistic fallacy is indeed a fallacy then this only raises the question: If it is indeed true that moral values cannot be derived from scientific facts, whence can moral values be derived?
Can they only be derived from other moral values? If so, how are our ultimate moral values, from which all other moral values are derived, themselves derived?
Singer does not address this. However, precisely by failing to address it, he seems to implicitly assume that our ultimate moral values must simply be taken on faith.
However, Singer also emphasizes that rejecting the naturalistic fallacy does not mean that the facts of human nature are irrelevant to politics.
On the contrary, while Darwinism may not prescribe any particular political goals as desirable, it may nevertheless help us determine how to achieve those political goals that we have already decided upon. Thus, Singer writes:
“An understanding of human nature in the light of evolutionary theory can help us to identify the means by which we may achieve some of our social and political goals… as well as assessing the possible costs and benefits of doing so” (p15).
Thus, in a memorable metaphor, Singer observes:
“Wood carvers presented with a piece of timber and a request to make wooden bowls from it do not simply begin carving according to a design drawn up before they have seen the wood. Instead they will examine the material with which they are to work and modify their design in order to suit its grain…Those seeking to reshape human society must understand the tendencies inherent within human beings, and modify their abstract ideals in order to suit them” (p40).
In addition to suggesting how our ultimate political objectives might best be achieved, an evolutionary perspective also suggests that some political goals might simply be unattainable, at least in the absence of a wholesale eugenic reengineering of human nature itself.
In watering down the utopian aspirations of previous generations of leftists, Singer seems to implicitly concede as much.
For this reason, communism is unobtainable because:
- People strive to promote themselves and their kin above others;
- Only coercive state apparatus can prevent them so doing;
- The individuals in control of this coercive apparatus themselves seek to promote the interests of themselves and their kin and corruptly use this coercive apparatus to do so.
Thus, Singer laments:
“What egalitarian revolution has not been betrayed by its leaders?” (p39).
Or, alternatively, as HL Mencken put it:
“[The] one undoubted effect [of political revolutions] is simply to throw out one gang of thieves and put in another.”
In addition, human selfishness suggests, if complete egalitarianism were ever successfully achieved and enforced, it would likely be economically inefficient – because it would remove the incentive of self-advancement that lies behind the production of goods and services, not to mention of works of art and scientific advances.
Thus, as Adam Smith famously observed:
“It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest.”
And, again, the only other means of ensuring goods and services are produced besides economic self-interest is state coercion, which, given human nature, will always be exercised both corruptly and inefficiently.
Singer’s pamphlet has been the subject of much controversy, with most of the criticism coming, not from conservatives, whom one might imagine to be Singer’s natural adversaries, but rather from other self-described leftists.
These leftist critics have included both writers opposed to evolutionary psychology (e.g. David Stack in The First Darwinian Left), but also some other writers claiming to be broadly receptive to the new paradigm but who are clearly uncomfortable with some of its implications (e.g. Marek Kohn in As We Know It: Coming to Terms with an Evolved Mind).
In apparently rejecting the utopian transformation of society envisioned by Marx and other radical socialists, Singer has been accused by other leftists for conceding rather too much to the critics of leftism. In so doing, Singer has, they claim, in effect abandoned leftism in all but name and become, in their view, an apologist for and sell-out to capitalism.
Whether Singer can indeed be said to have abandoned the Left depends, of course, on precisely how we define ‘the Left’, a rather more problematic matter than it is usually regarded as being.
For his part, Singer certainly defines the Left in unusually broad terms.
For Singer, leftism need not necessarily entail taking the means of production into common ownership, nor even the redistribution of wealth. Rather, at its core, being a leftist is simply about being:
“On the side of the weak, not the powerful; of the oppressed, not the oppressor; of the ridden, not the rider” (p8).
However, this definition is obviously problematic. After all, few conservatives would admit to being on the side of the oppressor.
On the contrary, conservatives and libertarians usually reject the dichotomous subdivision of society into ‘oppressed’ and ‘oppressor groups’. They argue that the real world is more complex than this simplistic division of the world into black and white, good and evil, suggests.
Moreover, they argue that mutually beneficial exchange and cooperation, rather than exploitation, is the essence of capitalism.
They also usually claim that their policies benefit society as a whole, including both the poor and rich, rather than favouring one class over another.
Indeed, conservatives claim that socialist reforms often actually inadvertently hurt precisely those whom they attempt to help. Thus, for example, welfare benefits are said to encourage welfare dependency, while introducing, or raising the level of, a minimum wage is said to lead to increases in unemployment.
Singer declares that a Darwinian left would “promote structures that foster cooperation rather than competition” (p61).
Yet many conservatives would share Singer’s aspiration to create a more altruistic culture.
Indeed, this aspiration seems more compatible with the libertarian notion of voluntary charitable donations replacing taxation than with the coercively-extracted taxes invariably favoured by the Left.
Nepotism and Equality of Opportunity
But this is no boon for egalitarians.
Rather, the fact that our selfishness is tempered by a healthy dose of nepotism likely makes equality of opportunity as unattainable as equality of outcome – because individuals will inevitably seek to aid the social, educational and economic advancement of their kin, and those individuals better placed to do so will enjoy greater success in so doing.
For example, parents with greater resources will be able to send their offspring to exclusive fee-paying schools or obtain private tuition for them; parents with better connections may be able to help their offspring obtain better jobs; while parents with greater intellectual ability may be able to better help their offspring with their homework.
However, since many conservatives and libertarians are as committed to equality of opportunity as socialists are to equality of outcome, this conclusion may be as unwelcome on the right as on the left.
Indeed, the theory of kin selection has even been invoked to suggest that ethnocentrism is innate and ethnic conflict is inevitable in multi-ethnic societies, a conclusion unwelcome across the mainstream political spectrum in the West today, where political parties of all persuasions are seemingly equally committed to building multi-ethnic societies.
Unfortunately, Singer does not address any of these issues.
Animal Liberation After Darwin
Singer is most famous for his advocacy on behalf of what he calls animal liberation.
In ‘A Darwinian Left’, he argues that the Darwinian worldview reinforces the case for animal liberation by confirming the evolutionary continuity between humans other animals.
This suggests that there are unlikely to be fundamental differences in kind as between humans and other animals (e.g. in the capacity to feel pain) sufficient to justify the differences in treatment currently accorded humans and animals.
Thus, Singer concludes:
“By knocking out the idea that we are a separate creation from the animals, Darwinian thinking provided the basis for a revolution in our attitudes to non-human animals” (p17).
This makes our consumption of animals as food, our killing of them for sport, our enslavement of them as draft animals, or even pets, and our imprisonment of them in zoos and laboratories all ethically suspect, since these are not things generally permitted in respect of humans.
Yet Singer fails to recognise that human-animal continuity cuts two ways.
Thus, anti-vivisectionists argue that animal testing is not only immoral, but also ineffective, because drugs and other treatments often have very different effects on humans than they do on the animals used in drug testing.
Our evolutionary continuity with non-human species makes this argument less plausible.
Moreover, if humans are subject to the same principles of natural selection as other species, this suggests, not the elevation of animals to the status of humans, but rather the relegation of humans to just another species of animal.
In short, we do not occupy a position midway between beasts and angels; we are beasts through and through, and any attempt to believe otherwise is mere delusion.
Finally, acceptance of the existence of human nature surely entails recognition of carnivory as a part of that nature.
Thus, just because meat-eating may be natural for humans, in the sense that meat was a part of our ancestors diet in the EEA, this does not necessarily mean that it is morally right or even morally justifiable.
However, the fact that meat is indeed a natural part of the human diet does suggest that, in health terms, vegetarianism is likely to be nutritionally sub-optimal.
Thus, the naturalistic fallacy or appeal to nature fallacy is not always entirely fallacious, at least when it comes to human health. What is natural for humans is indeed what we are biologically adapted to and what our body is therefore best designed to deal with.
Therefore, vegetarianism is almost certainly to some degree sub-optimal in nutritional terms.
Moreover, given that Singer is an opponent of the view that there is a valid moral distinction between acts and omissions, then we must ask ourselves: If he believes it is wrong for us to eat animals, does he also believe we should take positive measures to prevent lions from eating gazelles?
Bemoaning the emphasis of neoliberals on purely economic outcomes, Singer protests:
“From an evolutionary perspective, we cannot identify wealth with self-interest… Properly understood self-interest is broader than economic self-interest” (p42).
Singer is right. The ultimate currency of natural selection is not wealth, but rather reproductive success – and, in evolutionarily novel environments, wealth may not even correlate with reproductive success (Vining 1986).
Whereas Marxists see societal conflict and exploitation as reflecting competition over control of the means of production, for Darwinians, all societal conflict ultimately concerns control over, not the means of production, but rather what we might term the means of reproduction – in other words, women, their wombs and vaginas.
“The ultimate measure of human success is not production but reproduction. Economic productivity and profit are means to reproductive ends, not ends in themselves” (The Ethnic Phenomenon: p165).
Thus, for all his ostensible radicalism, Karl Marx, in his emphasis on economics (‘production’) at the expense of sex (‘reproduction’), was just another Victorian sexual prude.
Competition or Cooperation: A False Dichotomy?
In Chapter Four, entitled “Competition or Cooperation?”, Singer argues that modern western societies, and many modern economists and evolutionary theorists, put too great an emphasis on competition at the expense of cooperation.
Singer accepts that both competition and cooperation are natural and innate facets of human nature, and that all societies involve a balance of both. However, different societies differ in their relative emphasis on competition or cooperation, and that it is therefore possible to create a society that places a greater emphasis on the latter at the expense of the former.
Thus, Singer declares that a Darwinian left would:
However, Singer is short on practical suggestions as to how a culture of altruism is to be fostered.
Changing the values of a culture is not easy. This is especially so for a liberal democratic (as opposed to a despotic, totalitarian) government, let alone for a solitary Australian moral philosopher – and Singer’s condemnation of “the nightmares of Stalinist Russia” suggests that he would not countenance the sort of totalitarian interference with human freedom to which the Left has so often resorted in the past, and continues to resort to in the present (even in the West), with little ultimate success, in the past.
On the contrary, perhaps the most remarkable acts of cooperation, altruism and self-sacrifice are those often witnessed in wartime (e.g. kamikaze pilots, suicide bombers and soldiers who throw themselves on grenades). Yet war represents perhaps the most extreme form of competition known to man.
In short, soldiers risk and sacrifice their lives, not only to save the lives of others, but also to take the lives of other others.
Likewise, trade is a form of cooperation, but are as fundamental to capitalism as is competition. Indeed, I suspect most economists would argue that exchange is even more fundamental to capitalism than is competition.
But, for Ridley, our capacity for cooperation provides a rationale, not for socialism, but rather for free markets – because humans, as natural traders, produce efficient systems of exchange which government intervention almost always only distorts.
However, whereas economic trade is motivated by self-interested calculation, Singer seems to envisage a form of reciprocity mediated by emotions such as compassion, gratitude and guilt.
However, sociobiologist Robert Trivers argues in his paper that introduced the concept of reciprocal altruism to evolutionary biology that these emotions themselves evolved through the rational calculation of natural selection (Trivers 1971).
Therefore, while open to manipulation, especially in evolutionarily novel environments, they are necessarily limited in scope.
Singer’s envisaged ‘Darwinian Left’ would, he declares, unlike the contemporary left, abandon:
“[The assumption] that all inequalities are due to discrimination, prejudice, oppression or social conditioning. Some will be, but this cannot be assumed in every case” (p61).
This is probably Singer’s most controversial suggestion, at least for modern leftists, since it contravenes the contemporary dogma of political correctness.
Singer is, however, undoubtedly right.
Moreover, his recognition that some differences in achievement as between groups reflect, not discrimination, oppression or even the lingering effect of past discrimination or oppression, but rather innate differences between groups in psychological traits, including intelligence, is by no means incompatible with socialism, or leftism, as socialism and leftism were originally conceived.
Thus, it is worth pointing out that, while contemporary so-called ‘cultural Marxists’ may decry the notion of innate differences in ability and temperament as between different races, sexes, individuals and social classes as anathema, the same was not true of Marx himself.
On the contrary, in famously advocating ‘from each according to his ability, to each according to his need’, Marx implicitly recognized that people differed in “ability” – differences which, given the equalization of social conditions envisaged under communism, he presumably conceived of as innate in origin.
As Hans Eysenck observes:
“Stalin banned mental testing in 1935 on the grounds that it was ‘bourgeois’—at the same time as Hitler banned it as ‘Jewish’. But Stalin’s anti-genetic stance, and his support for the environmentalist charlatan Lysenko, did not derive from any Marxist or Leninist doctrine… One need only recall The Communist Manifesto: ‘From each according to his ability, to each according to his need’. This clearly expresses the belief that different people will have different abilities, even in the communist heaven where all cultural, educational and other inequalities have been eradicated” (Intelligence: The Battle for the Mind: p85).
Thus, Steven Pinker, in The Blank Slate, points to the theoretical possibility of what he calls a “Hereditarian Left”, arguing for a Rawlsian redistribution of resources to the, if you like, innately ‘cognitively disadvantaged’.
Instead, he illustrates the possibility that not “all inequalities are due to discrimination, prejudice, oppression or social conditioning” with the marginally less incendiary case of sex differences.
Here, it is sex differences, not in intelligence, but rather in temperament, preferences and personality that are probably more important, and likely explain occupational segregation and the so-called gender pay gap.
Thus, Singer writes:
“If achieving high status increases access to women, then we can expect men to have a stronger drive for status than women” (p18).
However, Singer neglects to mention another biological factor that is also probably important in explaining the gender pay gap – namely, women’s attachment to infant offspring. This factor, also innate and biological in origin, also likely impedes career advancement among women.
Thus, it bears emphasizing that never-married women with no children actually earn more, on average, than do unmarried men without children of the same age in both Britain and America.
For a more detailed treatment of the biological factors underlying the gender pay gap, see Biology at Work: Rethinking Sexual Equality by professor of law, Kingsley Browne, which I have reviewed here and here. See also my review of Warren Farrell’s Why Men Earn More, which can be found here, here and here.
Dysgenic Fertility Patterns?
It is sometimes claimed by opponents of welfare benefts that the welfare system only encourages the unemployed to have more children so as to receive more benefits and thereby promotes dysgenic fertility patterns. In response, Singer retorts:
“Even if there were a genetic component to something as nebulous as unemployment, to say that these genes are ‘deleterious’ would involve value judgements that go way beyond what the science alone can tell us” (p15).
Singer is, of course, right that an extra-scientific value judgement is required in order to label certain character traits, and the genes that contribute to them, as deleterious or undesirable.
Indeed, if single mothers on welfare do indeed raise more surviving children than do those who are not reliant on state benefits, then this indicates that they have higher reproductive success, and hence, in the strict biological sense, greater fitness than their more financially independent, but less fecund, reproductive competitors.
Therefore, far from being ‘deleterious’ in the biological sense, genes contributing to such behaviour are actually under positive selection, at least under current environmental conditions.
However, even if such genes are not ‘deleterious’ in the strict biological sense, this does not necessarily mean that they are desirable in the moral sense, or in the sense of contributing to successful civilizations and societal advancement. To suggest otherwise would, of course, involve a version of the very appeal to nature fallacy or naturalistic fallacy that Singer is elsewhere emphatic in rejecting.
Thus, although regarding certain character traits, and the genes that contribute to them, as undesirable does indeed involve an extra-scientific “value judgement”, this is not to say that the “value judgement” in question is necessarily mistaken or unwarranted. On the contrary, it means only that such a value judgement is, by its nature, a matter of morality, not of science.
Thus, although science may be silent on the issue, virtually everyone would agree that some traits (e.g. generosity, health, happiness, conscientiousness) are more desirable than others (e.g. selfishness, laziness, depression, illness). Likewise, it is self-evident that the long-term unemployed are a net burden on society, and that a successful society cannot be formed of people unable or unwilling to work.
As we have seen, Singer also questions whether there can be “a genetic component to something as nebulous as unemployment”.
However, in the strict biological sense, unemployment probably is indeed partly heritable. So, incidentally, are road traffic accidents and our political opinions – because each reflect personality traits that are themselves heritable (e.g. risk-takers and people with poor physical coordination and slow reactions probably have more traffic accidents; and perhaps more compassionate people are more likely to favour leftist politics).
Thus, while it may be unhelpful and misleading to talk of unemployment as itself ‘heritable’, nevertheless traits of the sort that likely contribute to unemployment (e.g. intelligence, conscientiousness, mental and physical illness) are indeed heritable.
Actually, however, the question of heritability, in the strict biological sense, is irrelevant.
Thus, even if the reason that children from deprived backgrounds have worse life outcomes is entirely mediated by environmental factors (e.g. economic or cultural deprivation, or the ‘bad parenting’ practices of low-SES parents), the case for restricting the reproductive rights of those people who are statistically prone to raise dysfunctional offspring remains intact.
After all, children usually get both their genes and their parenting from the same set of parents – and this could be changed only by a massive, costly, and decidedly illiberal, policy of forcibly removing offspring from their parents.
Therefore, so long as an association between parentage and social outcomes is established, the question of whether this association is biologically or environmentally mediated is simply beside the point, and the case for restricting the reproductive rights of certain groups remains intact.
Of course, it is doubtful that welfare-dependent women do indeed financially benefit from giving birth to additional offspring.
It is true that they may receive more money in state benefits if they have more dependent offspring to support and provide for. However, this may well be more than offset by the additional cost of supporting and providing for the dependent offspring in question, leaving the mother with less to spend on herself.
However, even if the additional monies paid to mothers with dependent children are not sufficient as to provide a positive financial incentive to bearing additional children, they at least reduce the financial disincentives otherwise associated with rearing additional offspring.
Therefore, given that, from an evolutionary perspective, women probably have an innate desire to bear additional offspring, it follows that a rational fitness-maximizer would respond to the changed incentives represented by the welfare system by increasing their reproductive rate.
A New Socialist Eugenics?
If we accept Singer’s contention that an understanding of human nature can help show us how achieve, but not choose, our ultimate political objectives, then eugenics could be used to help us achieve the goal of producing the better people and hence, ultimately, better societies.
Indeed, given that Singer seemingly concedes that human nature is presently incompatible with communist utopia, perhaps then the only way to revive the socialist dream of equality is to eugenically re-engineer human nature itself so as to make it more compatible.
Thus, early twentieth century socialist-eugenicists like H.G. Wells, Sidney Webb, Margaret Sanger and George Bernard Shaw may then have tentatively grasped what eludes contemporary leftists, Singer very much included – namely that re-engineering society necessarily requires as a prerequisite re-engineering Man himself.
 Indeed, the view that the poor and ill ought to be left to perish so as to further the evolutionary process seems to have been a marginal one even in its ostensible late nineteenth century heyday (see Bannister, Social Darwinism Science and Myth in Anglo-American Social Thought). The idea always seems, therefore, to have been largely, if not wholly, a straw man.
 In this, the evolutionary psychologists are surely right. Thus, no one accuses biomedical researchers of somehow ‘justifying disease’ when they investigate how infectious diseases, in an effort maximize their own reproductive success, spread form host to host. Likewise, nobody suggests that dying of a treatable illness is desirable, even though this may have been the ‘natural’ outcome before such ‘unnatural’ interventions as vaccination and antibiotics were introduced.
 The convenional notion that we can usefully conceptualize the political spectrum on a single dimensional left-right axis is obviously preposterous. For one thing, there is, at the very least, a quite separate liberal-authoritarian dimension. However, even restricting our definition of the left-right axis to purely economic matters, it remains multi-factorial. For example, Hayek, in The Road to Serfdom classifies fascism as a left-wing ideology, because it involved big government and a planned economy. However, most leftists would reject this definition, since the planned economy in question was designed, not to reduce economic inequalities, but rather, in the case of Nazi Germany at least, to fund and sustain an expanded military force, a war economy, external military conquest and grandiose vanity public works architectural projects. The term ’right-wing‘ is even more problematic, including everyone from fascists, to libertarians to religious fundamentalists. Yet a Christian fundamentalist who wants to outlaw pornography and abortion has little in common with either a libertarian who wants to decriminalize prostitution and child pornography, nor with a eugenicist who wants to make abortions, for certain classes of person, compulsory. Yet all three are classed together as ’right-wing’ even though they share no more in common with one another than any does with a raving unreconstructed Marxist.
 Thus, the British Conservatives Party traditionally styled themselves ‘one-nation conservatives’, who looked to the interests of the nation as a whole, rather than what they criticized as the divisive ‘sectionalism’ of the trade union and labour movements, which favoured certain economic classes, and workers in certain industries, over others, just as contemporary leftists privilege the interests of certain ethnic, religious and culturally-defined groups (e.g. blacks, Muslims, feminists) over others (i.e. white males).
 Of course, some ‘unnatural’ interventions have positive health benefits. Obvious examples are modern medical treatments such as penicillin, chemotherapy and vaccination. However, these are the exceptions. They have been carefully selected and developed by scientists to have this positive effect, have gone through rigorous testing to ensure that their effects are indeed beneficial, and are generally beneficial only to people with certain diagnosed conditions. In contrast, recreational drug use almost invariably has a negative effect on health.
It might also be noted that, although their use by humans may be ‘unnatural’, the role of antibiotics in fighting bacterial infection is not itself ‘unnatural’, since antibiotics such as penicillin themselves evolved as a natural means by which one microorganism, namely mould, a form of fungi, fights another form of microorganism, namely bacteria.
 It is certainly possible for more altruistic cultures to exist. For example, the famous (and hugely wasteful) potlatch feasts of some Native American cultures exemplify a form of competitive altruism, analogous to conspicuous consumption, and may be explicable as a form of status display in accordance with Zahavi’s handicap principle. However, recognizing that such cultures exist does not easily translate into working out how to create or foster such cultures, let alone transform existing cultures in this direction.
 The term Rawlsian is a reference to political theorist John Rawles version of social contract theory, whereby he poses the hypothetical question as to what arrangement of political, social and economic affairs humans would favour if placed in what he called ’the original position’, where they would be unaware of, not only their own race, sex and position in to the socio-economic hierarchy, but also, most important for our purposes, their own level of innate ability. This Rawles referred to as ’veil of ignorance’.
 As Warren Farrell documents in his excellent Why Men Earn More (which I have reviewed here, here and here), in the USA, women who have never married and have no children actually earn more than men who have never married and have no children and have done since at least the 1950s (Why Men Earn More: pxxi). More precisely, according to Farrell, never-married men without children on average earn only about 85% of their childless never-married female counterparts (Ibid: pxxiii). The situation is similar in the UK. Thus, economist JR Shackleton reports:
“Women in the middle age groups who remain single earn more than middle-aged single males” (Should We Mind the Gap? p30).
The reasons unmarried, childless women earn more than unmarried childless men are multifarious and include:
- Married women can afford to work less because they appropriate a portion of their husband’s income in addition to their own
- Married men and men with children are thus obliged to earn even more so as to financially support, not only themselves, but also their wife, plus any offspring;
- Women prefer to marry richer men and hence poorer men are more likely to remain single;
- Childcare duties undertaken by women interfere with their earning capacity.
 Incidentally, Browne has also published a more succinct summary of the biological factors underlying the pay-gap that was first published in the same ‘Darwinism Today’ series as Singer’s ‘A Darwinian Left’, namely Divided Labors: An Evolutionary View of Women at Work. However, much though I admire Browne’s work, this represents a rather superficial popularization of his research on the topic, and I would recommend instead Browne’s longer Biology at Work: Rethinking Sexual Equality (reviewed here) for a more comprehenseive treatment of the same, and related, topics.
 A precedent for just such a programme, enacted in the name of socialism, albeit imposed consensually, was the communal rearing practices in Israeli Kibbutzim, since largely abandoned. Another suggestion along rather different lines comes from Adolf Hitler, who, believing that nature trumped nurture, is quoted in Mein Kampf as proposing:
“The State must also teach that it is the manifestation of a really noble nature and that it is a humanitarian act worthy of all admiration if an innocent sufferer from hereditary disease refrains from having a child of his own but bestows his love and affection on some unknown child whose state of health is a guarantee that it will become a robust member of a powerful community” (quoted in: Parfrey 1987: p162).
 Actually, it is not entirely clear that women do have a natural desire to bear offspring. Other species probably do not have any such natural desire. Since they are almost certainly are not aware of the connection between sex and child birth, such a desire would serve no adaptive purpose and hence would never evolve. All an organism requires is a desire for sex, combined perhaps with a tendency to care for offspring after they are born. (Indeed, in principle, a female does not even require a desire for sex, only a willingness to submit to the desire of a male for sex.) As Tooby and Cosmides emphasize:
There is no requirement for a desire for offspring as such. Nevertheless, anecdotal evidence of so-called broodiness, and the fact that most women do indeed desire children, despite the costs associated with raising children, suggests that, in human females, there is indeed some innate desire for offspring. Curiously, however, the topic of broodiness is not one that has attracted much attention among evolutionists.
 However, there is a problem with any such case for a ‘Brave New Socialist Eugenics’. Before the eugenic programme is complete, the individuals controlling eugenic programmes (be they governments or corporations) would still possess a more traditional human nature, and may therefore have less than altruistic motivations themselves. This seems to suggest then that, as philosopher John Gray concludes in Straw Dogs: Thoughts on Humans and Other Animals (which I have reviewed here):
“[If] human nature [is] scientifically remodelled… it will be done haphazardly, as an upshot of the struggles in the murky world where big business, organized crime and the hidden parts of government vie for control” (Straw Dogs: p6).
Trivers 1971 The evolution of reciprocal altruism Quarterly Review of Biology 46(1):35-57
Vining 1986 Social versus reproductive success: The central theoretical problem of human sociobiology. Behavioral and Brain Sciences 9(1), 167-187.