Sexual selection as race making

Abstract

Charles Darwin's theory of sexual selection, as described in The Descent of Man, and Selection in Relation to Sex (1871), should be viewed as a significant transitional point in the modern expression of race. Unlike earlier race theorists, Darwin proposed that sexual reproduction was not merely a testing ground of racial character, but was itself a causal force that could create new races. His account of race was distinctly modern – viewing race not in terms of blood but as a collection of population-level characteristics. Recognizing this feature of Darwin's sexual-selection theory allows us to situate Darwin's work not solely within the history of evolutionary science, but also within the structures of racism that became the governing principles of modern nation states. In other words, sexual selection is an expression of Michel Foucault's biopolitics, in which political power is exercised by states not through the contracts of liberal governance but through the management of population-level phenomena. Furthermore, by contextualizing sexual selection in this theoretical framework, it becomes possible to more clearly emphasize the importance of race in the rise of modern biopolitics.

Charles Darwin's theory of sexual selection, first published in his 1871 volume The Descent of Man, and Selection in Relation to Sex was a pivotal transition between the scientific race theories of the first half the nineteenth century, when slavery was still legal in much of the Anglo-American world, and the height of the eugenics movement at the turn of the twentieth century. The race theorists in the generation before Darwin had conceptualized sexual encounters between the races as the mixing of stable blood essences. Racial character could be diluted, or kept pure, through sexual exchange, but the fundamentals of that character were not altered. Darwin's evolutionary theory proposed something different – he suggested that the selection of sexual partners could influence the set of traits that survived in a racial type, actually molding and changing the features of that race. This conceptual shift signalled an important transition in the modern expression of race. Race was no longer understood as originally created by God, and only alterable through the direct action of environmental influence, or racial degradation. Rather, it was a natural feature of human populations that could be shaped by the sexual choices of individual men and women.

And the question of race was a much-debated one for Anglo-American intellectuals throughout the nineteenth century. Theologians and naturalists proposed racial theories that were alternatively grounded in biblical tradition or in the new sciences of ethnology, heredity and transmutation. But despite their differences, male intellectuals often demonstrated their mutual respect for one another – a feature of their discourse that stands out in their scientific correspondence.¹ For instance, in an 1849 letter from the American Lutheran minister and naturalist John Bachman to Samuel George Morton, upon their disagreement about the unity of the races, Bachman amended that despite their differences, ‘we are both in search of the truth’ and ‘at some point I believe our views will harmonize’.² Even at times of bitter disagreement, men of science in the nineteenth-century Anglo-American world were invested in the respect and approbation of their peers. The legitimation and circulation of their scientific knowledge depended upon this esteem, and they had access to the luxury of an intellectual life not solely through their achievements, but by virtue of the social and economic position of their race, class and gender.

Rather than portraying these men as the primary agents of this world, we might consider their scientific practices as attempts to make sense of the great natural experiment in human population mixing that had been ongoing for several centuries because of the African slave trade and the Columbian exchange. Defining the results of this race mixing was essential to the legal architecture of slavery in the United States and the colonies of the West Indies, for determining citizenship and identity in Great Britain, and for defining citizenship in the United States after the end of the Civil War. We write about Darwin and other men of science because they were the elites of their own time and thus documented their perspectives in scientific publications, correspondences and diaries. We have far fewer records of the bodies that became the objects of their race science – the bodies of mixed-race persons that were created and remade by the sexual realities of race making in this period. Thus, while we can read about the views of Darwin or American race theorists on the fertility of mulatto women, it is far harder to recover the feelings and experiences of the latter.

To this end, I set Darwin's theory of sexual selection as a transition between two major episodes of modern race making: first, the use of ethnology in the development of polygenism in the American school of anthropology, and second, the beginning of the international eugenics movement. I read this transition through the bodies and experiences of two mixed-race women – one historical and the other fictional. The first section details the trial of Alexina Morrison, a blonde blue-eyed woman who sued for her freedom before the American Civil War by contending that she was in reality white, and therefore had been illegally captured into slavery. The second section explores the imaginative landscape of Charles Chesnutt's 1900 The House behind the Cedars and the romantic travails of Rena Warwick, the mixed-race woman at the heart of the novel. Through the stories of these two women, as incomplete, fragmented and even fictional as they are, I connect the material embodiments of race with the scientific world of Darwin's evolutionary theories.

After all, it is an important scholarly task solely to write the intellectual history of Darwin's The Descent of Man. And in doing so, we find ourselves astonished that we ever considered the book as anything other than a proposal for the relationship between sexuality and race. We become incapable of discussing sexual selection without also discussing race, despite its twentieth-century incarnation.³ We understand how to bridge the anatomical and ethnological race sciences of the early nineteenth century to the population race science of early twentieth-century eugenics. And this is deeply satisfying, for in trying to understand what kind of thing race is, how it functions, how it is embodied and materialized, how it is written onto and read into bodies, then to know more clearly the logical structure of nineteenth-century race science is a good in itself. But it is not enough. It is not enough for me, as a feminist and critical-race scholar, nor as a twenty-first-century mixed-race person. Instead, let us see the practice of race science as a kind of imaginative act – a creative force in the making of race, not interchangeable, but also not entirely separate from the material circumstances that brought together previously geographically isolated human populations, or the ability for slave masters to father children and sell them in the slave economy of the Atlantic world. For race is not something that we merely observe in the world, as if it were static. It is something that we do with our bodies, as we organize and label, as we partner and marry and have children.

Considering The Descent of Man in this light, we learn much more than Darwin's personal views of race, slavery and human evolution. Indeed, we recognize that the Darwinian view of race and sexuality – in which humans, not God, have control over race through their reproductive decisions – is fundamental to what race is in the modern world. This is not my insight, of course – Michel Foucault argued in The History of Sexuality and accompanying lectures that the modern state sees its citizens not as individuals but as part of a population – and it is the population, not citizens, whose health must be observed and managed.⁴ Subsequent scholars, notably Ann Stoler in Race and the Education of Desire and more recently Kyle Schuller in The Biopolitics of Feeling, have greatly expanded on Foucault's initial suggestions by demonstrating the ongoing entanglements between race and the state management of human sexuality in modernity.⁵ Here I argue that Darwinian sexual-selection theory was part of the rise of state biopower at the end of the nineteenth-century state, because of its conviction that sexuality had the capacity to engineer humanity's racial futures.

Alexina Morrison: polygenism, blood and affinity

The gaze of nineteenth-century Anglo-American medics and naturalists was fixed upon the sexual dimensions of race mixing. Were racial hybrids sterile? Were mulatto women more sexually profligate than black or white women? Did brown people exhibit intermediate intelligence and attractiveness between whites and blacks – or was the mixture of races an inevitable degeneracy, rendering mixed-race people below blacks and Native Americans? These were pressing questions for the legal architecture of slavery in Anglo-America during the antebellum period but continued to preoccupy naturalists during the racial uncertainties of Reconstruction, and through the waves of immigration and industrial revolutions of the turn of the twentieth century. Throughout this period, the bodies and sexual practices of mixed-race men and women were examined for clues as to the results of race mixture. Determining the fertility of human race crossing was a key piece of evidence in nineteenth-century scientific debates over the nature of human racial variation.

In May of 1859, the lawyers of Alexina Morrison presented new evidence to a jury in the lower State Court House of Louisiana. It came in the form of a witness, a man named John L. Riddell, a resident of New Orleans and a professor at the nearby medical college of Louisiana.⁶ Riddell was called upon to present his view on the central question of the case – was Alexina a white woman and entitled to her legal freedom, as she claimed, or was she of mixed parentage and therefore an escaped slave? Riddell brought to the court a novel piece of evidence – a strand of Alexina's hair, which he had taken from her head and examined under a microscope. He declared to the court that after he had ‘prepared a careful examination of the hair of this girl with a proper apparatus’ and then analysed it, he determined that the hair was ‘of the moderate oval characteristic of the Caucasian or white race’.⁷ Riddell's scientific expertise was out of place, or at least an unusual occurrence, in an antebellum Louisiana court room. Why was Riddell there? And why was his testimony being used on behalf of Alexina's claim to whiteness? To answer these questions, we have to consider both the woman on trial and the circumstances that led Riddell to believe that a cross-section of hair would reveal something significant about her.

Alexina was a blonde blue-eyed woman who sued for her freedom in the late 1850s on the basis of the claim that she was white. Morrison's case was unusual in the history of manumission trials, as it was only one of a dozen or so in which enslaved status was judged on the basis of uncertain racial identity, rather than being a dispute over documentation.⁸ Morrison's case ended indeterminately, with a jury unable to decide whether she was white, and subsequent trials were interrupted by the Civil War. Her record disappears after the war and her final fate has been lost to history. The case has generated some considerable degree of historical interest; because of its unique features Morrison v. White has been an important case study for historians interested in how the law fashioned race categories during American slavery.⁹ The role that scientific experts played in the trial, however, has proved to be a greater historical puzzle. As Ariella Gross relates in her study of antebellum race-determination trials, early nineteenth-century cases usually did not involve the testimony of scientific experts.¹⁰ In fact, such testimony is entirely absent from these cases before 1850. Gross and other historians have attempted to make sense of this absence by highlighting the greater importance of experiential and common-sense definitions of race. However, there is a straightforward reason why scientific experts only appeared at trials after 1850 – there was little in the way of a professional scientific community in the first decades of the early American republic.¹¹ Riddell represented a new era of American science and was part of a network of naturalists that extended out from Philadelphia through a web of education and intellectual patronage. It was centered in the person of Samuel George Morton, one of the leading figures in the new American school of anthropology, and a key proponent of the new polygenist racial theory. Morton and other polygenists contended that the human races were distinct species that had been separately created by God to suit the climates of their region of geographic origin.

At the heart of the American school was a desire to establish an empirically grounded theory for human racial difference that utilized the evidence of nature, rather than that of Scripture. The members of this scientific community viewed themselves as pioneers against the dogma of religious tradition. Josiah Nott, another important figure in the school, made this clear to Morton in a letter from 1844:

Your conclusion that the races, as far as facts can have them are distinct, I think is the only one which reason can arrive at. You have gone far enough according to my notions to blow up all chronologies, although it may not be politic to say so in these days of Christian intolerance – the Bible if of divine origin, was clearly not intended to include, in its code of beautiful morals, the whole range of natural science, for it shows no knowledge beyond the human knowledge of the day & its great ends did not require any other – even the Septuagint account is far too short to take in the events of Egypt, to say nothing of Geological formations which are now placed before the ‘beginning’ of Moses.¹²

Nott was inspired by Morton's lead in setting aside the biblical chronology in favour of new historical evidence of the ancient origins of humanity that was fast arriving from archaeological digs in Egypt.¹³ This scientific confidence also galvanized another key feature of polygenism: its interest in grounding scientific theory in empirical evidence. Through observation, collection and measurement, the American school built a racial theory out of the features of modern science. And in doing so, they became the first internationally recognized movement of American science.

John Riddell was thus characteristic of many who belonged to Morton's polygenism network. He was a medical man who had a great interest in natural history. In fact, he had garnered some degree of fame after inventing the first practical binocular microscope, which he used to examine Alexina's hair during the trial.¹⁴ He corresponded directly with Morton and became a subscribing member of the Philadelphia Academy of Science, of which Morton was the head.¹⁵ During Alexina's trial, Riddell referenced the work of another naturalist of the American school – Peter A. Browne, who had published on the use of hair in the classification of human racial hybrids in his 1852 work The Classification of Mankind by the Hair and Wool of Their Heads, with the Nomenclature of Human Hybrids.¹⁶ Browne compiled this work in consultation with Morton; Morton sent him samples of hair from his collection and Browne offered selections of the manuscript for Morton's insight before its final publication.¹⁷ During his trial testimony, Riddell referred to ‘Brown [sic] a distinguished servant of Philadelphia’ as an expert who claimed ‘that there is a peculiar difference in the hair in its texture of a person of African descent from that of a white person’ – and his own observations had ‘served to verify what Mr. Brown has asserted’.¹⁸ Through Riddell's testimony, the empirical confidence and enthusiasm of American polygenism was brought to bear on the fate of Alexina Morrison.

In the historical study of evolutionary science, polygenism is generally dismissed as a pre-Darwinian non-evolutionary theory that was defeated by Darwin's argument for common descent. Further, the reputation of these figures as examples of scientific racism was established in the 1980s through the writings of evolutionary scientist and public intellectual Stephen Jay Gould, who enshrined Morton as an exemplar of racial bias in science in his 1981 book The Mismeasure of Man.¹⁹ The perhaps unintended consequence of this critique is that there has been little attention to the continuities between the investigations of the American school and the work of later evolutionary scientists on the subject of race theory. And this has meant that historians have generally disregarded the similarity of scientific questions and objects between polygenist and evolutionary science. However, both groups looked to the bodies and fertility of mixed-race persons in an attempt to discern a systematic relationship between sexual reproduction and racial character. And the differences in their theories are particularly clear in their divergent arguments regarding the fertility of mixed-race women.

Despite caricatures of polygenists and other pre-Darwinian naturalists, Morton, Nott, and others of the American school did not believe in the absolute immutability of species. Since the medieval period, European naturalists had recognized the great variability of results when two parents came together to produce offspring. What early periods did not settle on was a methodical way of conceptualizing biological inheritance; that is, a science of heredity. But as Staffan Müller-Wille and Hans-Jörg Rheinberger have argued, by the late nineteenth century a science of heredity emerged out of a broader epistemic space that reached new heights of systematic scientific investigation with the advent of modern genetics in the early twentieth century.²⁰ In the lead-up to this new hereditary science, early nineteenth-century naturalists expanded their use of crossing and breeding experiments, spurred by the expansion and commodification of global agriculture and husbandry. These studies often focused on hybridization – what happened when two distinct variations, strains or even species were bred together. As part of this tradition, Nott and Morton conceptualized hybridization as a physiological process that could reveal the nature of the relationship between two parent varieties. Together with his colleague George Gliddon, Nott compiled and authored Types of Mankind in 1857 as a tribute to the craniometric studies of Morton. Nott built upon Morton's studies in order to expound a more full-throated argument for polygenism. In this passage from the book, Nott explained his view of the usefulness of hybridity for determining racial types:

Hybridity, heretofore, has generally been treated as if it were a unit; whereas its facts are as susceptible of classification as any other series of physiological phenomena. For the terms remote, allied, and proximate species, there will be frequent call; and, in consequence the reader is requested to look back (supra, p. 81) in this volume, to understand the meanings which, in common with Morton, I attach to them.²¹

Nott wanted empirical proof of the distinctive origins of the different human races, but he was also invested in having a system to categorize those races. In Types of Mankind he argued that it was possible to study the results of hybridization crosses in order to learn whether two races were closely or distantly related to one another. He reasoned that the more closely related – or proximate – that two species were to one another, the greater the likelihood that they would produce fertile and vigorous offspring. Conversely, more dissimilar (or remote) species would be less likely to produce viable offspring. And in the polygenist classification system, Caucasians from Europe, particularly Anglo-Saxons, and Negroes from Africa were not only separate species – they were the most distantly remote species.

Nott sought evidence for this claim in the bodies and behaviour of mulatto women. In an 1843 paper published in the American Journal of the Medical Sciences titled ‘The mulatto a hybrid: probable extermination of the two races if the whites and blacks are allowed to intermarry’, Nott put forward the empirical evidence of the resulting sterility and death of offspring between whites and blacks.²² And he rested his claims on evidence of the relative lack of fertility in mulatto women,

3^d. That the mulatto women are particularly delicate – are subject to many chronic diseases, and especially derangement of the catatonia, prolapsus uteri, leucorrhoea, and other diseases peculiar to females.

4^th. That the women are bad breeders and bad nurses – many of them do not conceive at all – most are subject to abortions, and large portion of their children die at any early age.

5^th. That the two sexes when they intermarry are less prolific, than when crossed on one of the parent stocks.

6^th. That the above facts apply with more force to the Terceroons and Quadroons than to Mulattoes.²³

The article, published a decade before Types of Mankind, was the first of Nott's medical papers and earned him some degree of fame; as he later related to Morton in 1849, his ‘Niggerology so far from harming me at home, has made me a greater man than I ever expected to be’.²⁴ Nott was committed to the view that the human races were separate species, and that any sexual contact between them was to be avoided at all costs. His claim that mixed-raced women were less fertile was key to his argument that mixture between the white and black races would lead to high rates of sterility and death.²⁵

When it came to humans, both polygenists and Darwin looked to the slave societies of the United States, Brazil and the European colonies of the West Indies as natural experiments from which to examine the results of sexual mixing between human races. The Atlantic slave trade had created a great geographic event, one fraught with both economic possibilities and social anxieties for Europeans and those of European descent in the Americas. Intermixture between Europeans and African slaves destabilized the color line that was essential to the legal infrastructure of slavery. But the fecundity of enslaved persons also represented a direct economic benefit to their owners, a fact that became a violent reality in the United States after the end of the Atlantic slave trade in 1808. No longer able to rely on, but also not forced to compete with, the importation of African slaves, the US internal slave trade boomed in the early decades of the century. The plantations on the eastern seaboard sold slaves to the newly opened lands of Mississippi and Texas, where a ravenous cotton industry was fed by the enforced migration of the internal slave trade.²⁶ For many slave owners on the East Coast, slaves represented a far more important capital product than the goods of agriculture. And in the United States, the compounding fact that enslaved status ‘followed the womb’ meant that it was an open secret that most slave owners were buying and selling their own relatives; offspring the product of sexual relationships of various degrees of violence and coercion. Although the historical scholarship is divided over whether white plantation owners deliberately bred slaves for sale, it is clear that breeding capacity was included in sale advertisements of enslaved women.²⁷ Thus the human results of race crossing simultaneously became the objects of natural history as well as the commodities of early nineteenth-century slavery. Were the offspring of Europeans and Africans fertile? What race did they belong to? These were not solely scientific questions, but had real implications for the lives of enslaved persons in this period.

Polygenists turned to the American South and the West Indies as important sites for observing the results of sexual exchange between persons of European and African descent. In his letters to Morton, Nott often referenced his own experiences, living and working in Alabama as proof of his expertise on the subject of race mixing.²⁸ Morton, on the other hand, spent much less time in the South, particularly toward the end of his life when his health failed him. His residence in the intellectual centre of Philadelphia did mean that he crossed paths with the largest and most prominent community of free middle-class African American intellectuals in the nation. And he lived on the same street as Sarah Mapps Douglass, a free African American woman of mixed parentage who was a close friend and confidant of the Grimké sisters, prominent leaders of the early women's rights and abolitionist movements.²⁹ Sarah, in fact, took classes at the Philadelphia Medical School where Morton was a professor, and she utilized his medical text in her coursework.³⁰ However, there is little evidence that Morton recognized the intellectual subjectivity of mixed-race women in his city. He viewed mixed-race persons as scientific objects, not as interlocutors or equals. Although Morton did not live in a slave state, he had travelled to Barbados in 1834, and recorded his observations of the island's slave communities in his diary. Most of his observations spoke derisively of the enslaved persons he met; in one entry he remarked,

How the sudden acquisition of freedom will affect a vast population of uneducated minds, is an experiment that remains to be decided … [the slaves] are uncultivated, and by nature indolent; and it is scarcely to be supposed that with the choice between idleness and industry, they will not adopt the former.³¹

In another entry, he commented with some wonder and also disgust on the slaves of ‘all shades of color, from the ebony negro to the light mulatto’, that he observed in the island's capital.³² For Morton and other polygenists, their scientific arguments were continually leveraged as political justification for slavery.

Members of the American school were deeply committed to preserving and promoting the white race. Their fears of racial amalgamation were somewhat ameliorated, however, by their belief in the lack of sexual attraction between the races. Morton was confident that members of different races were naturally disgusted at the prospect of sexual contact. He argued this in an 1847 paper, ‘Hybridity in animals, considered in reference to the question of the unity of the human species’, claiming that

the repugnance of some human races to mix with others, has only been partially overcome by centuries of proximity … and repugnance … appears to be almost equally natural to the Africans … for with the former a white skin is not more admired than a black one is with us.³³

Morton's view that members of the same race shared an intuitive affinity was also echoed by the witnesses at Alexina's trial. Several of the witnesses in the case claimed that they were able to discern the truth of Alexina's racial identity because of an instinctive ability to recognize others of their own race. As one witness expressed it, he knew Alexina's race, just as ‘the alligator … knows three days in advance that a storm is brewing’.³⁴ Sexual attraction was the fullest expression of this intuitive identification – Morton, as well as the witnesses at Alexina's trial, believed that members of the same race would naturally be drawn to one another. And for Alexina, this confidence in sexual affinity strengthened her claims to whiteness. The very fact that white members of her community had recognized her as white, had allowed her in their homes, watched her being courted by their sons, and drawn into friendships with their daughters, meant that she must be white. It was too frightening to consider the alternative possibility.

Rena Warwick: sexual selection and the creation of race

The polygenists were confident – or at least hopeful – that the natural repugnance that the races felt for one another would sexually sequester them. But there were many in Anglo-America who were far less assured in this erotic distaste, particularly after the American Civil War. With the end of slavery, the possibilities for legitimate interracial intimacy struck fear in the hearts of white America. Although interracial sex had been a feature of American society since before its founding, the legality of slavery ensured that the children of white and black parents were slaves. But after the war, many of the political contests of the Reconstruction Era centred on the new possibilities for legal interracial marriage. If former slaves were now full political subjects, did it not follow that they could also enter into legal unions with white citizens? Although many states already had in place restrictions against interracial sex, laws against interracial marriage dramatically increased after the passage of the Civil War amendments to the Constitution.³⁵ White Americans wanted to ensure that de jure political equality did not lead to lawful interracial romance.

The social parameters involved in choosing a spouse were a trope that also occupied nineteenth-century Anglo-American fiction from the writings of Austen to James. And the restrictions of class and social expectation that were inherent to the marriage plot inevitably revealed the cultural preoccupations of these novelists. A few authors from this period elected to venture into especially thorny social territory – what did romantic choice look like across the color line? The answer to that question was usually one of social heartache, or even horrific death, for the characters involved. For instance, in 1864, Louisa May Alcott chose a bitter end for the heroine of her novel Moods, who dared to traverse the racial boundaries of her day.³⁶ One of the first American novels to address this quandary by an author who was themself mixed-race was Charles Chesnutt's 1900 novel The House behind the Cedars. Chesnutt's fiction explored the ambiguities, difficulties and longings of his own life, as he did not feel that he fit entirely in either black or white society.³⁷ The House behind the Cedars explores the romantic travails of Rena Warwick, who is of mixed race, but so light-skinned that she passes for white. She is initially courted by a white man, but once he discovers her mixed parentage he rejects her; she then rebuffs the advances of a mulatto man and subsequently dies from an attack of brain fever. Throughout the novel, Chesnutt imbues his characters with scientific knowledge of their romantic choices; the novel is peppered with Darwinian language from ‘variation’ to ‘descent’, ‘adaptation’ and, importantly, ‘selection’. And Chesnutt uses this evolutionary language to frame the romantic decisions of his characters.³⁸ But the paradox at the heart of The House behind the Cedars is that while Chesnutt presents Rena and her brother John as superior examples of the black race, they have no clear path to marriage in front of them. Rena attempts to make a choice to better her race, but is incapable of doing so, because of the very fact of her own mixed parentage. Caught in a sexual and racial paradox, she dies tragically.

Chesnutt's conferral of the burden of choice upon Rena owes much to the work of Charles Darwin.³⁹ Darwin's writings on sexual selection helped shape a new racial imaginary in the Anglo-American world. As it had been for polygenists, racial erotic preference was a key argument for Darwin's theory of sexual selection. But Darwin argued that this sexual preference was not merely like finding like; rather these sexual choices had perpetuated the subtle differences between groups of humans, which over time had caused significant racial divergence. He transformed racial sexual preference from mere identification to an engine of evolutionary progress.

When Darwin published On the Origin of Species in 1859, it was immediately involved in ongoing debates about race and slavery in the United States. Most abolitionist intellectuals, particularly in the Transcendentalist circles of New England, interpreted the Origin as a scientific refutation of the polygenist argument for the separate creation of the human races.⁴⁰ Transcendentalists were drawn to Darwin's argument for the common descent of animals, which they inferred must also apply to humans. By proposing a naturalistic mechanism of species differentiation, Darwin's work was understood to be a refutation of the theory of special creation, and thus of the primary theoretical foundation of polygenism. But the question remained for Darwin's claim of common descent: how could humanity have evolved from a common ancestor and yet exhibit the variability in skin colour and – what nineteenth-century European and American men of science believed was obvious – the differences in anatomy, temperament and intelligence exhibited by the world's races? Darwin's purpose in The Descent of Man was to make the case that common descent applied to humans, and, within that theory, to account for the variation of race.

As had the polygenists, Darwin turned to the moment of sexual exchange between the sexes as the site at which to study racial character. But unlike the American school, Darwin did not view sexual reproduction as a testing ground for racial character, but rather as a causal force. He proposed something novel – that sexual reproduction was itself a mechanism of evolutionary change. He did so by arguing that it was differences in sexual preferences that had driven the creation of human races; through mate selection the erotic attraction to skin colour, facial angles, musical ability or hair texture had produced racial variation. And Darwin reasoned that this selective force had been at play in the early stages of man's history; he made this point in Chapter 19 of the Descent:

We are chiefly concerned with primeval times, and our only means of forming a judgment on this subject is to study the habits of existing semi-civilised and savage nations. If it can be shewn that the men of different races prefer women having various characteristics, or conversely with the women, we have then to enquire whether such choice, continued during many generations, would produce any sensible effect on the race, either on one sex or both according to the form of inheritance which has prevailed.⁴¹

Sexual selection became Darwin's solution to the question of race in part because of the logic of natural selection, his first proposed mechanism of evolutionary change. As the theory was outlined in On the Origin of Species, traits that conferred greater survival advantage on an individual allowed them to survive and pass those traits on to subsequent generations, thus preserving the traits and influencing the evolutionary future of the whole population. But natural selection did not account for attributes – such as the ornamental feathers of birds, the antlers of a deer or the racial features of humans – that did not seem to contribute to survival. Importantly, Darwin argued in the Descent that racial traits were not subject to natural selection, since they did not qualify as ‘beneficial variations’ because ‘as far as we are enabled to judge … none of the differences between the races of man are of any direct or special service to him’.⁴² If Darwin could not explain the races with natural selection, he was left with the prospect of attributing them to the work of special creation. But he was unwilling to concede this view and thus proposed sexual selection as an additional selective mechanism of evolutionary change. By turning to sexual selection, Darwin could argue that instead of environmental or competitive pressures exerting selection based on survival criteria, selection occurred also through erotic reproductive preference. If natural selection had taken the design of the living world out of the hands of God and placed it in the purview of nature, then sexual selection placed that creative force in the sexual choices of individuals.

Darwin was not merely content to propose the possibility that sexual selection could happen. Although the mechanism was a logical solution to the issue of racial variation, he also wanted empirical proof that sexual selection was, in fact, at work in the natural world. The second and longest part of The Descent of Man presented Darwin's accumulated evidence of sexual selection throughout the natural world, beginning with the lower animals and concluding with humans.⁴³ If Darwin could convince his readers that sexual selection did in fact occur, it would lend weight to his argument that racial variation was the result of natural causes, rather than of divine creation.

Darwin was by no means the first Anglo-American man to argue that sexual preference revealed something about racial character. Even before polygenism, Anglo-American naturalists during the eighteenth century believed that sexual preference accompanied common racial origin. The great French naturalist Georges-Louis Leclerc, comte de Buffon, had argued in 1749 that ‘we should regard two animals as belonging to the same species if, by means of copulation, they can perpetuate themselves and preserve the likeness of the species’.⁴⁴ Within the divinely ordered Great Chain of Being, sexual congress should only be possible between individuals of the same kind. The disruptions brought on by the American and French Revolutions to this natural hierarchy manifested in panic over the spectre of interracial sex. In the decades following American independence, Thomas Jefferson was lampooned by the national press for his sexual proclivities and his republican beliefs. In the logic of the eighteenth-century Chain of Being, interracial desire and liberal democracy were one and the same – by claiming that all men were created equal, Jefferson laid open the possibility that black Americans would claim the right to white spouses.⁴⁵ Naturalists in the following century would attempt to argue that sexual preference actually followed along racial lines. In 1848, the New York lawyer William Frederick van Amringe published a text arguing that it was part of God's natural order that sexual love was directed within racial groups. And he claimed that the ‘difference of taste for sexual beauty in the several races of man’ had been the most effective means of ‘keeping distinct … the different species of men’.⁴⁶

Darwin was familiar with the existing literature on sexual preference and racial variation.⁴⁷ But by the time he published Descent, he took this older tradition and transformed its assumptions. Sexual choice was no longer a means to discover the racial essences that had been designated by God in his plan for the natural order. Instead it was a natural force, one that could be controlled by humanity, allowing us to determine our evolutionary futures. By the time of publication, he was also well aware that polygenism was thus far the most influential empirically based theory of race in the Anglo-American world. Accordingly, he organized the first chapter in the Descent that directly addressed human racial variation (Chapter 7, ‘On the races of man’) as a serious consideration and eventual refutation of the polygenist claims.⁴⁸ In private, however, Darwin was largely dismissive of the work of the American school. In a letter to Charles Lyell from 1847, he discussed Morton's work regarding the sterility of hybrids, but complained that Morton's ‘worse fault is that he has not gone to his original source’, and informed Lyell that he did ‘not think Dr. Morton a safe man to quote from’, a damning estimation in natural-science circles.⁴⁹ Darwin included Morton's papers on hybridity in his ‘books to be read’ section of his reading notebook, although he informed Asa Gray that he believed Morton's 1850 paper ‘On the question of hybridity in animals, considered in reference to the unity of the human species’ to be ‘poor’.⁵⁰ But although he could disparage Morton and the other polygenists to his closest colleagues, in print he was obligated to contend with the weight of their arguments. After all, the American school represented the most thorough and well-respected empirical race theory of the nineteenth century. Darwin could not simply reject it out of hand.

The issue of hybrid fertility was at the core of Darwin's debates with the polygenists. In the Descent, Darwin acknowledged that it was generally assumed that any resulting sterility from crossing two variations was ‘considered as a decisive test’ that they belonged to separate species.⁵¹ Given this, he agreed that it seemed reasonable to study mixed-race women to determine whether they were fertile or not. If it was true as had ‘often been said that when mulattoes intermarry they produce few children’, Darwin proposed to his readers that this might seem like strong evidence against the unity of humankind. However, the issue was not so simple. In the first place, Darwin pointed out to his readers that the scientific literature was not in agreement over the evidence regarding mulatto sterility. He put forward Bachman's claim that ‘he has known mulatto families which have intermarried for several generations, and have continued on an average as fertile as either pure whites or pure blacks’.⁵² But even this was not conclusive; instead Darwin amended that the subject was more complex that a simple test of fertility might suggest. Instead, he argued, it was necessary for men of science to reframe the issue. Rather than seeing sexual preference as a testing ground for racial character, he moved from this debate to building his case for the role of sexual choices in the fashioning of race.

By arguing that choice formed racial types, Darwin extended his vision for a true history of life that he had articulated in the Origin of Species in 1859. One of the key conceptual transformations engendered by Darwin's theories was the move to think of biological traits on a horizontal, rather than vertical, scale. Previous generations of naturalists had imagined that traits were conferred on individuals by a divine source; Darwin envisioned them emerging through variation and then circulating, or disappearing, depending on the survival success of the particular trait. As Rheinberger and Müller-Wille have argued, before Darwin, ‘Generation [was] reduced to a strictly formal relation of descent, constituting the species as a set of individuals determined in essentially the same uniform way by a “procreative” unit instituted by God at the beginning of time.’⁵³ But Darwin, as illustrated in the single famous image in the Origin, was part of a transformation that envisioned a horizontality to life. In his view life was no ‘longer dominated by direct relations among organisms’, but instead by ‘interactions among circulating units of life … that are transmitted and redistributed from generation to generation’.⁵⁴ In other words, Darwin's theories disrupted the relationship between God and the act of procreation. He imagined a history for life that was not shaped by iterative instances of God's divine hand, but instead through a series of contingent survival moments that determined which traits survived and spread through a population. Considering sexual selection in this light, it becomes clear that the theory similarly wrested the action of God out of the mechanism for racial traits. And in this case choice, not survival, was the key to the distribution and redistribution of racial features.

However, in arguing that Darwin's theory of sexual selection represented a reconstitution of the discursive grammar of sexuality and race, I do not contend that it was the most important causal force in this transformation. That is, although Darwin's theory was read widely across the Anglo-American world, it was not necessarily the most influential evolutionary schema of its era. In many national contexts, including the United States, the progressive views of Herbert Spencer and the directed transmutation of neo-Lamarckianism were far more significant. This is one reason why Schuller argues that scholars should focus on neo-Lamarckian theories in their efforts to understand the creation of the ‘biopolitical phenomenon of population’.⁵⁵ But by concentrating on Darwin's work in this essay, my intent has been to trace moments of a new discursive possibility, of which sexual-selection theory was a clear signatory. How did states come to manage life, to conceive of people not as individual citizens or subjects, but as population markers? The rise of biopower came about through massive upheavals in the legal, social and material structures of the eighteenth and nineteenth centuries. It was made by the forces of industrial capitalism and the Atlantic slave trade. And it shaped the intuitions of generations of elites, as they sought to improve, create and prune the character of nation states. This did not all come about because of Darwin. But Darwin's theories helped to make it thinkable, for these forces to be put into words and concepts. And in the iterative relationship between materiality and theory, Darwin made concrete the engineering power of sex.

Thus, while the analysis I offer in this essay is indebted to the work of historians such as Evelleen Richards,⁵⁶ my own effort has been less toward Darwinian intellectual history and instead has reached for a vocabulary to describe a new intuition about the relationship between sexuality and race. When sexual reproduction became the link between individuals and the collective racial future of nations, it also emerged as the most important site for elite management and self-production. The secularization of racial theory, far from relieving the social surveillance of sexual behavior, in fact made sexual choices far more consequential. And nowhere was this more clear than in the rise of the international eugenics movement of the early twentieth century.

Darwin's own connection to eugenics has been a fraught historical question, not least because of the human atrocities that were rendered by the institutional and intellectual work of eugenicists.⁵⁷ Setting aside the question whether Darwin was morally culpable for eugenics, let us instead consider the conceptual shifts enacted by his theory of sexual selection that opened up new imaginary possibilities for eugenics. Above all, eugenics was a science of human improvement that took the confidence of hereditary and evolutionary science and applied it to the governance of nation states and European colonies. Sexual selection introduced two critical aspects of this movement, both of which figured in a letter that Darwin wrote to his cousin and undisputed progenitor of eugenics, Francis Galton, two years after the publication of the first edition of the Descent. Darwin sent a letter to his cousin after reading Galton's article ‘Hereditary improvement’, in which Galton laid out his plan of improving the human race through selective marriage and a heredity registry.⁵⁸ Darwin was largely sceptical of Galton's ideas, seeing ‘much difficulty’ in the ‘utopian plan of … improving the human race’, but he saw great merit in Galton's idea ‘to disseminat[e] & insist on the importance of the all-important principle of Inheritance’.⁵⁹ This was the first critical point – with natural selection, Darwin had introduced the notion that humans were in control of heredity through their reproductive decisions. By offering an entirely naturalistic account of racial variation, Darwin helped convince the Anglo-America world that race was not defined by God, but made by humanity. But this also introduced a secondary and essential piece of the eugenic logic – because humanity had this power, it was incumbent upon individuals to know and understand the power of ‘the principle of Inheritance’. With The Descent of Man, Darwin had conferred a new burden of reproductive choice upon the world.

After all, Rena Warwick was not the only tragic eugenic figure in turn-of-the-twentieth-century fiction. Her marriage prospects were fraught because she could not make a good race choice. Already mixed, she was incapable of breeding a true stock and so her relationships with both a white man and a black one failed in catastrophe and death. In fact, as American studies scholars have explored in recent decades, the literary world of the late nineteenth century was replete with the importance of the eugenic marriage choice, in everything from the essays of Charlotte Perkins Gilman, to the poetry of Walt Whitman, to the novels of Nella Larsen.⁶⁰ Through these fictive worlds, American authors attempted to discern what duty individuals owed to their race in making their reproductive decisions. But this obligation to achieve eugenic reproduction influenced far more than just turn-of-the-twentieth-century literature. It shaped the political and economic infrastructures of national and colonial governments, affecting everything from tax codes, to conservation movements, to public-health campaigns.⁶¹ Most significantly, it brought the power of race into the hands of humanity. Eugenic rhetoric was full of the confidence of the scientific approach to fashioning the world; as one biologist wrote in 1922, ‘eugenics means a new religion, a new moral code, a new social and political Bible’.⁶² Although it is impossible to say whether these changes would have come about without the work of Charles Darwin, it is clear that sexual selection enacted a dramatic theoretical shift in the work of race making in the modern era.