Sown Without Care: Dutch Eugenicists and their Call for Optimising Developmental Conditions, 1919–1939

Summary

Introduction

At the end of 1920, cell biologist Marianne van Herwerden (1984–1934) returned to the Netherlands from a scientific tour throughout the USA. She had visited the laboratories of leading biologists such as Edmund Wilson, Alexis Carrel and Thomas Hunt Morgan. More than anything, however, the Eugenics Record Office at Cold Spring Harbor made a deep impression.¹ Van Herwerden had become convinced that the reproduction of individuals carrying hereditary deficits could lead to the ‘degeneration’ of society. Eugenic research, she increasingly believed, had the potential to make intelligible which characteristics could be passed on to future generations and how these were distributed within a population.² Back in the Netherlands, Van Herwerden became the leading organisational and intellectual force behind eugenic research in the 1920s and 1930s. She thereby contributed to a global movement of eugenic scholars investigating the hereditary quality of populations. Yet, in contrast to this international community, Van Herwerden was hesitant about the practical application of eugenics research. She explicitly dismissed the reproductive sterilisation legislation as it would be implemented in foreign countries, such as Sweden, Germany and the USA.³ Instead, Van Herwerden emphasised that Dutch eugenicists wanted to keep their movement ‘pure and dismiss all prejudices regarding the greater or lesser eminence of one or the other race—something that many German and Scandinavian eugenicists fail to understand correctly’.⁴

Today, inspired by the historiographic trend to compare the intellectual, organisational and political shape of eugenics across various national contexts, accounts on the rise of eugenics in the period leading up to the Second World War highlight the internationally exceptional position of the Netherlands.⁵ In their aim to distil a transnational core of eugenics across national contexts, they highlight that while many countries in the 1920s and 1930s implemented compulsory sterilisation laws, the Dutch government did not put any reproductive legislation into force. This discrepancy has repeatedly sparked curiosity in the existing historiography on national eugenics movements. For a long time after the Second World War, eugenics was equated primarily with sterilisation practices and is remembered as the scientific legitimisation of reproductive intervention during the Nazi Regime.⁶ Hence, the fact that in the Netherlands, the presence of eugenic thinking did not result in sterilisation policies was something warranting explanation—as an illogical abbreviation of the status quo. Most famously, this explanation was provided by Jan Noordman’s seminal 1989 history of the Dutch eugenics movement. He clarifies the absence of regulatory interventions in the Netherlands by pointing at the marginality of eugenic thinking in the Dutch political debate. The main reason he provides is that the liberal and confessional politicians that governed the Netherlands during the interwar period rejected centralised state interference in reproductive activities, which they regarded to be an issue belonging to the private sphere.⁷

Since the 1980s, historical research has moved away from approaching eugenics as a monolithic object of study and has instead taken the inconsistencies and opposing views within the international eugenic movement as a point of departure.⁸ In this literature, eugenic discourse is interpreted as offering a conceptual toolkit from biology for understanding and thinking about solutions for problems resulting from modernisation processes such as industrialisation, urbanisation and nation-building.⁹ This perspective clarifies the diversity of proposals inspired by eugenic discourse—beyond sterilisation policies. In this vein, more recent historical work on the Netherlands has called the marginality of eugenics in the Netherlands into question.¹⁰ Most notably, Stephen Snelders, Toine Pieters and Pim Huijnen move away from political discourse and show by means of a text-mining approach that the concept of ‘heredity’ was in fact regularly used in newspapers to discuss all sorts of social problems in biological terms. To these digital historians, this indicates a more central place of eugenic thinking in Dutch society than Noordman suggests.¹¹ Yet, their perspective does not explain that, while eugenic thinking seems to be a visible presence in Dutch public discourse, this did not result in any significant eugenics practice. Why was that?

In this paper, I answer this question by analysing how Dutch eugenicists themselves thought about the relationship between their research and its potential application. In doing so, I show that Marianne van Herwerden’s hesitance to eugenic sterilisation policy represents the Dutch eugenic movement during the interwar years and, crucially, that this position followed from a specific conceptualisation of heredity in relation to degeneration. In this article, I follow those who identified themselves as ‘eugenicist’ and medical and biological authors who explicitly addressed ‘applied heredity theory’ and ‘eugenics’ as their topic of concern. My source material consists of textbooks, periodical publications and printed lectures in which these authors explicitly articulated the meaning and potential application of ‘eugenics’ during the interwar years. This emphasis on actor’s categories not only reveals how this group of authors understood collective degeneration as an undesired consequence of increasing ‘civilisation’. Such an approach also clarifies which solutions they proposed and how these were legitimised. I will show that it is essential to interpret Dutch authors on eugenics as ‘public health reformers’ aiming to improve and sustain the health of the future population. As such, this narrative builds upon historical work highlighting the intellectual overlap and collaboration between eugenicists and public health activists during the interwar years.¹² Moreover, my story substantiates this perspective by showing that the attempt of Dutch eugenicists to secure a place within the domain of public health went hand in hand with how they employed the concept of heredity to explain curative medicine and sanitary reform as required for optimising developmental conditions. Dutch eugenicists stood out for dismissing the ‘Lamarckian’ possibility of inheriting acquiring characteristics without taking a genetic determinist stance. This position legitimised the need for environmental reform to ensure individual’s health for the benefit of the population. This paper thereby not only explains that Van Herwerden’s worries about degeneration were compatible with her dismissal of applied eugenics in the form of sterilisation policy. By showing how rejecting the immediate application of eugenic research held a central place in Dutch eugenic discourse, I also intend to provide a contribution to future comparative accounts aiming to understand eugenics as a transnational phenomenon taking shape in different national contexts.¹³

A Relevant Discipline That Should Not Immediately Be Applied

In the Netherlands, the term ‘eugenics’ (in Dutch: ‘eugenese’) was commonly used interchangeably with ‘applied hereditary theory’ (in Dutch: ‘toegepaste erfelijkheidsleer’). Its precise meaning initially took shape by explaining what it was not about. In a report on her visit to the US Eugenics Record Office in Cold Spring Harbor in 1920, which she wrote for the Dutch Journal of Medicine, Marianne van Herwerden was happy to recognise hesitancy to immediate implementation of eugenic research:

I had expected that the Eugenic Record Office would propagate laws regarding sterilisation policies and marriage laws as they were applied in some North American states. On a meeting of the Eugenics Research Association, which I attended at Cold Spring Harbor, it appeared that the contrary was the case: the association fiercely opposed premature measures that discredit the good cause of eugenic research.¹⁴

This ‘good cause’ referred to research to prevent physical and psychological decay, or ‘degeneration’. According to Van Herwerden, a ‘scientific’ eugenics, which was based on a ‘proper’ understanding of ‘actual’ heredity, should be distinguished from a eugenics ‘associated with all kinds of wild notions regarding the prohibition of reproduction’.¹⁵ Her criticism of sterilisation centred around attempts to create an ‘ideal race’ by preventing individuals with undesired traits from reproducing. Such plans reflected an ‘unscientific understanding of heredity’ which had nothing to do with ‘eugenics proper’.¹⁶ Her biggest objection to an ‘ideal race’ focussed on desired characteristics rather than traits that were ‘actually’ inherited. Racial reformers abused variation statistics to map the distribution of characteristics within a population to identify individuals belonging to that superior race, Van Herwerden argued.¹⁷This was problematic since the norm—the peak of an imaginary bell curve—was not absolute. What was desired of an ‘ideal race’ differed across historical and social contexts.¹⁸ According to the leading Dutch eugenicist:

Yet it must not be hidden that what is regarded as the norm may at some time, after a few centuries, lie outside the norm, leading to a displacement of the norm as implied by a standard deviation. This applies not only to the well-known displacement in the norm of morals and customs within a society, in the displacement of moral conceptions of right and wrong, but also of purely physical properties.¹⁹

Van Herwerden explained attempts to create such a specific ‘ideal’ race by sterilising outliers to prevent them from reproducing as not only resulting from an inadequate understanding of biology. Unjustified ‘political prejudices’ about what is desirable within a population played an obstructing part as well.²⁰

This self-proclaimed apolitical attitude was not only promoted by Marianne van Herwerden. Her professional attitude of worried but certainly cautious academics represented the approach of authors writing about applied heredity theory in the Netherlands during the 1930s and 1940s. This becomes especially clear after examining how Dutch eugenicists discussed the potential application of their work. The commencement speech of Jan Anthonie Honing (1880–1950) at the occasion of his appointment as rector magnificus of the Agricultural College at Wageningen in 1934 illustrates this attitude. Honing was a renowned Dutch geneticist. He wrote his dissertation supervised by Hugo de Vries, who is still credited as one of the three ‘rediscoverers’ of Mendel’s laws. He had been a professor of heredity theory at the universities of Amsterdam and Utrecht in the 1920s. His inaugural lecture, called ‘Heredity and Society’, addressed how eugenics could help prevent social degeneration.

Discussing the ethical and religious issues around sterilisation policies, Honing elaborated on how in Germany, a research commission under the direction of the notorious eugenicist Eugen Fischer (1874–1967) had concluded that from a biological point of view, sterilisation might potentially be a fruitful way to prevent diseased individuals from reproducing. However, the Wageningen professor pointed out that it was impossible to determine which degenerate traits were inherited and could be passed on to future generations based on sound science. He emphasised how difficult it was to distinguish traits that were ‘actually’ heritable and ‘apparently’ heritable.²¹ Therefore, Honing dismissed massive sterilisation campaigns, such as those following the 1934 sterilisation laws in Germany as premature.²² With outrage, Honing stated that ‘race delusion, morbid exaggeration, or perhaps even the attempt to ridicule issues regarding heredity, seems to inspire some to speak of millions of people that would qualify for forced sterilisation’.²³

Discussions about the German sterilisation laws of the 1930s allowed Dutch eugenicists to frame themselves as the ‘cautious’ and ‘purely scientific’ discipline they envisioned to be. Most textbooks written at the beginning of the 1920s were reprinted as expanded new editions in the early 1930s. Marius Sirks, for example, published the second edition of his Handboek der Erfelijkheidsleer in 1933. ‘Passionate and fanatic racism, especially in recent years’, Sirks claimed, ‘increasingly influenced the application of heredity theory. I consider it my duty to safeguard our research subject and how its conclusions are put into practice, from subjective prejudice’.²⁴ New textbooks on applied heredity theory were written to help readers form an opinion on international developments. The catholic physician Johannes Schulte, who wrote his Erfelijkheid en Eugenetiek in 1938, was well aware of how the popularity of Dutch eugenics in the 1930s related to the questionable practices in Germany and presented his textbook as an antidote to such sentiments. Schulte unequivocally stated that ‘over the last couple of years, especially in Germany, heredity theory has been put into practice (sterilisation, hygienic racial measures, etc.). In that regard, eugenics seems to have left the context of research and entered public life’.²⁵ As a result, every right-minded citizen, Schulte expected, had to be aware of the problematic nature of the hasty, political application of eugenics research.²⁶

This cautiousness reflected debates around governmental interference with reproduction in the Dutch parliament, comparable to French interwar political discourse.²⁷ With a strong emphasis on autonomous citizenship, liberal-confessional cabinets during the interwar years envisioned the central government to be reluctant to top-down interference with private life.²⁸ In that context, responsible ministers approached any item that appeared in some sense influenced by eugenic thinking with great hostility, often playing it down as an ‘inappropriate’ subject to discuss in the national parliament. Not even a single member of parliament ever explicitly proposed to implement ‘eugenic laws’.

The avoidance of the notion of ‘eugenics’ also applied to parliamentary debate about pronatalist policies, such as child allowance. Even though some authors perceived caring for population health by means of ensuring enough new children of selected parents as an example of ‘positive eugenics’, it was never explicitly presented as such in the Dutch political arena.²⁹ In a similar vein, the hesitance to discuss ‘eugenics’ did not mean that the Dutch parliament did not at all discuss measures to prevent supposedly ‘degenerate’ individuals from reproducing. In the 1934 budget debate of the justice department, for instance, the conservative-liberal member Louis ridder van Rappard (1904–1994) plead for the legislation for therapeutic castration of degenerate sex offenders. The Catholic minister of Justice Josef van Schaik (1882–1962) objected that castration policy interfered too much with reproductive autonomy: ‘the individual doesn’t exist for the sake of the state, but the contrary is the case: the state exists for the sake of the individual’.³⁰ In this political climate, it is not so much a surprise that sterilisation to prevent reproduction for social goals was never seriously proposed and discussed in the Dutch parliament. It only appeared as a political topic in 1937 as a side issue while debating financial support for legal counsel for Jewish political refugees entering the Netherlands at the eve of the Second World War. Social democrat Leendert Donker (1899–1956) stated with aversion how Jewish refugees were confronted with ‘disgusting measures’ such as ‘concentration camps, sterilisation and other anti-Jewish policies’.³¹ Here, the practice of eugenics in other countries was even an argument to welcome refugees.

Echoing this political hesitance towards state-led reproductive interference, the few academics propagating eugenics understood their discipline as a relevant but immature domain of inquiry. Their research program had as its primary goal to determine characteristics that were ‘actually’ heritable and chart their distribution in a population. Only in the second instance could this knowledge of human heredity be applied to prevent degeneration. Dutch eugenicists were critical of sterilisation policies to create an ideal race. At the same time, however, they supported the ambition to prevent hereditary degeneration. To understand this somewhat paradoxical position, we need to apprehend how Dutch eugenicists framed and legitimised their professional identity.

Eugenics as Public Health Reform

How to apply research that should not ‘immediately’ be applied? To understand this apparent contradiction, it is helpful to follow the lead of historians such as Martin Pernick, Peter Weingart and Deborah Kamrat-Lang, and interpret Dutch eugenics as a form of public health.³² According to this interpretation, eugenics was focussed on the medical goal to preventing physical ‘degeneration’, rather than being an ‘anthropological’ discipline that aimed to identify and sustain racial hierarchies.³³ ‘Their main concerns were parallel but different’ as Peter Weingart argued, ‘what fear of racial impurity was to the anthropologists; the fear of physical degeneration was to the physicians’.³⁴ Medical eugenics aimed to prevent decay by maintaining collective health.

It is indeed sensible to interpret Dutch eugenics as having a medical rather than an anthropological agenda. Not only because of their explicitly critical stance towards ‘racial delusion’ and creating ‘an ideal race’, but also because eugenics in the Netherlands primarily professionalised on the initiative of physicians. The first attempt to explicitly organise ‘eugenics’ took place in 1914, when A.E.W. Toe Laer became highly disappointed by the absence of a Dutch delegacy at the first international eugenic conference in 1912 in London.³⁵ At a public meeting of the Amsterdam consultation office for premarital examination, the physician proposed to initiate a ‘Dutch Eugenic Association’. Notably, only medical professionals could become a member—sociologists, philosophers and ‘others’ were explicitly not allowed.³⁶ Despite its ambitions, the association failed to mobilise widespread enthusiasm for eugenics. It was a ‘weak attempt’, as Marianne van Herwerden later admitted in her textbook on human heredity in 1926.³⁷ Only after the First World War, in the early 1920s, a colourful alliance between geneticists and physicians rehabilitated eugenic initiative in the Netherlands.

Their initial endeavours began within the context of Het Nederlandsche Volk, an organisation dedicated to gaining an understanding of both quantitative and qualitative aspects of the Dutch population. In the mid-1920s, the association founded a subcommittee on ‘applied heredity theory’ in which again solely physicians were allowed to participate. The committee counted leading authors on eugenics and applied heredity among its members. Next to Marianne van Herwerden, who was a private lecturer in cytology and genetics at Utrecht University, also social democrat Gerrit Pieter Frets (1979–1957) participated. The latter was a physician in the mental asylum of Maasoord and would later become a professor of neurology in Rotterdam. He published extensively on alcoholism, eugenics, and heredity in the 1920s and 1930s. The duo was completed with the Catholic ophthalmologist Johannes Waardenburg, who would later become the successor of Marianne van Herwerden as a professor in Utrecht, Van Herwerden, Frets and Waardenburg became the driving force of Dutch eugenics during the interwar years. In 1924, the trio took the lead in the most forceful attempt to unite all existing organisations on eugenics and human heredity took place. In March of that year, Het Nederlandsche Volk, the Vereening tot Bevordering van het Geneeskundig Onderzoek vóór het Huwelijk, the Nederlandsche Genetische Vereniging and Nationaal Bureau voor Antropologie decided to collaborate under one overarching ‘Central Committee’. Later in 1930, when the committee gained official royal support, the association renamed itself the ‘Dutch Eugenic Federation’, following international examples with a similar name after becoming a member of the ‘International Eugenic Federation’. In the middle of the 1930s, most of the Dutch authors on applied heredity theory with an interest in ‘eugenics’ or eugenicists with an explicit interest in ‘applied heredity theory’ participated in activities of the ‘Dutch Eugenic Federation’ or were an active member.³⁸ A medical degree was in most cases a prerequisite for such a membership. As such, the professionalisation of eugenics in the early 1930s strengthened the organisational ties between Dutch medicine and the upcoming field of genetics. As a result, the meaning and scope of eugenics was primarily defined by geneticists with a medical interest and physicians with an interest in genetics.

Against this background, it is not surprising that most eugenicists found appointments as professors of heredity theory in medical faculties and presented their knowledge as particularly relevant in medical contexts. Marius Sirks, for example, apologised in his inaugural lecture as professor of genetics at the University of Groningen in the faculty of medicine for ‘not being a medical practitioner’ when he addressed his new medical students in 1937.³⁹ Ophthalmologist and eugenicists Johannes Waardenburg also emphasised the tight relationship between medicine and eugenics in his inaugural speech as a lecturer in genetics in the medical faculty of Utrecht University in 1934. ‘It would be wrong to allocate one of the subjects a one-sided significance; it is more helpful to speak of strong interaction. The rapid developments in the study of human heredity have been a precondition for medical breakthroughs’.⁴⁰

At the end of the 1930s, most eugenicists portrayed the study of heredity as being fully integrated into Dutch medicine. Many textbooks on heredity bore titles that stipulated eugenics within the domain of medicine. Florentinus Wibaut’s De betekenis der erfelijkheid voor de geneeskunde (1940) is an excellent example that ties together how Dutch authors on ‘applied heredity theory’ increasingly conceptualised eugenics as an integral part of medicine. ‘Eugenics is especially significant for medical professionals to understand the human race as a whole’. Knowledge of heredity, Wibaut concluded in the last chapter of his book, ‘with all its interesting problems and state-of-the-art solutions should be an incentive for a more biological orientation of medicine. The physician of the future’, Wibaut predicted, ‘will not only reason anatomically, physiologically, physical and chemical: they must learn to reason biologically’.⁴¹

Regardless of this optimism, the envisioned integration of eugenic thinking within the medical profession was neither straightforward nor unproblematic. Dutch eugenicists regarded sanitary reform and the increasing success of curative medicine as the most important fruits of the rising ‘civilisation’ of society. Waardenburg stated in his 1927 textbook De Biologische achtergrond van aanleg, milieu en opvoeding how medicial advances were ‘satisfactory from an ethical point of view’, but he identified negative consequences as well. They could potentially be the cause of degeneration: ‘the counter-selective effects of sanitary reform have to be recognised and taken seriously’. Underestimating the moral and ‘genetic’ dangers of medicine for ethical reasons would, according to Waardenburg lead to the paradoxical result of ‘an increased demoralisation, and hereditary degeneration of the population to which the social and medical reformer belonged’.⁴² Without intervention, a civilised culture would eventually lead to a degenerate society. How did Dutch eugenicists relate to such a depressing foresight?

The ‘counter-selective’ consequences of medicine made sense from what they called a ‘Darwinian’ point of view in which a population evolves in an environment with limited resources. Only the best-adapted organisms would survive and reproduce, a phenomenon that Charles Darwin called ‘natural selection’. Over time, this process caused change on a population level, making the species as a whole respond more efficiently to its environment. Individual death was, therefore, necessary for the survival of the population.⁴³ Darwin thus explained the relation between populations and their environments, inspired by Thomas Robert Malthus’s (1766–1834) Essay on the principle of population as a natural economy leading to equilibrium over time.⁴⁴ However, the advantages of modern society—or ‘civilisation’—interfered with this natural economy, enabling unfit individuals to survive and reproduce as well—a process that became known as ‘counter-selection’.

Dutch eugenicists were very much aware of these perceived dilemmas of modernity. Tine Tammes (1871–1947) stated in her 1919 inaugural lecture as the first Dutch professor of genetics that ‘in our current society, certain circumstances are leading to the degeneration of the population’.⁴⁵ Departing from what she called a ‘Darwinian’ framework, Tammes argued that the ‘struggle for existence’ had been softened by social and medical reform over the last couple of decades. This made ‘natural selection’ disappear into the background. Additionally, weaker and degenerate individuals did not die but instead got even more offspring. As a result, medical and social improvements—the virtues of modern society—lead to counter-selection in their reversal of the natural process of evolution. This could eventually result in the degeneration of society as a whole.

Tammes claimed that biologists responded in various ways to these perceived demographic challenges. ‘Some wanted to rehabilitate the struggle for existence in full force; they believed that in human society, weak individuals should perish inexorably so that the fit ones could survive’.⁴⁶ These eugenicists radically opposed all endeavours that held back natural selection; philanthropy was especially considered plain wrong.⁴⁷ Tammes dismissed such a ‘laissez-faire’ take on human evolution. In their attempts to apply Darwinism to humanity, these eugenicists failed to consider ‘the uplifting effect of acts of mercy and human affection’.⁴⁸ But she regarded such a viewpoint to be contradictory as well. On the one hand, Tammes argued, ‘the improvement of the human population is their most important ideal’, but the acts to achieve these ideals would be ‘degrading, and lower human morality to the level of the animal’.⁴⁹ For Tammes, Darwin’s laws did not apply in the same way to humans as they did to other animals because of humanoid moral consciousness.

Dutch eugenicists generally agreed with Tammes to distinguish humans from animals. They tirelessly emphasised how applying biological reasoning to the human race required caution. Marianne van Herwerden, for example, admitted in her textbook that the improvements in the environmental conditions for individual development ‘indeed lead to the preservation of hereditary factors that are undesired for the population as a whole’. From that perspective, Van Herwerden reasoned, ‘the human population has detached itself from natural selection which, in the plant and animal kingdom, would set aside the undesired organisms and condemn them to extinction’.⁵⁰ According to Leiden dermatologist and eugenicist Herman Werner Siemens (1891–1969), a lack of training in the natural and biological sciences fed a cultural pessimism: ‘too many praise the ignorant pessimism that understands the extinction of human populations as well as the inevitable death of the individual—despite all scientific progress—as a necessary biological event’.⁵¹ In the late 1930s, Dutch eugenicists reached the consensus that even though the biological mechanism of natural selection had disappeared in modern civilisation, the reformative activities that were part of this civilisation should not be abandoned.

This did not mean that Dutch eugenicists regarded degeneration as unimportant. On the contrary, in their united dismissal of laissez-faire public health approaches, they conceptualised eugenics as a humanitarian solution to the counter-selective consequences of public health reform and curative care. Jan Antonie Honing, for example, stated in 1934 that ‘eugenics aims to compensate the booming innovations of medical science—which keeps the weak alive and causes counter-selection—in the most humanitarian sense. Instead of selection at the cost of the individuals themselves, modern eugenicists argued for selection at the cost of unborn offspring’.⁵² In the Netherlands, authors who wrote on preserving the hereditary health of the population through eugenic measures considered themselves as ‘Darwinists’. They accepted the counter-selective consequences of ‘civilisation’ without assuming that this legitimised laissez-faire politics as an example of natural selection. If—In the distant future—eugenic knowledge would be put in practice, it would be in the form of the necessary humanitarian ‘check’ to prevent hereditary degeneration caused by counter-selective forces such as medical practice and sanitary reform.

Framing eugenics as a humanitarian compensation for counter-selection and an alternative to laissez-faire politics did not entirely resolve the tension between eugenics and medical progress. From a Darwinian point of view, collective degeneration progressed when individuals with degenerate traits reproduced more than people without such characteristics. Eugenics, in that regard, was oriented toward the future health of the population. Consequently, the health of ‘degenerate’ individuals had less priority. The orientation towards the population and the future contrasted with curative medicine focussing on the short term by improving individual health. How did Dutch eugenicists handle the tension between how they perceived the counter-selective consequences of modern medicine with their enthusiasm for public health reform?

Dutch authors on ‘applied heredity theory’ were well aware of the apparent discrepancy. They conceptualised eugenics, next to its compensating value, also complementary to existing initiatives improving individual health. Siemens, for instance, admitted the limitations of environmental improvements in his 1931 textbook about applied heredity theory. He argued that ‘every paratypic improvement (through hygiene, sport, nurturing, social measures) is limited to the lifetime of a single individual’. It did not enhance the health of the future population. Sanitary improvements ‘are completely indifferent to the next generations; its effect will only last if the environmental improvements themselves are maintained’.⁵³ Thus, environmental enhancements and therapeutic medical practices enhance individual health. Eugenics would then be required to maintain the health of the future population. ‘The results of environmental factors on the single individual are not without significance, and it determines the immediate condition of the population. A population that wants to stay at the same cultural, economic, and political level ought not to fail in caring for currently living individuals while keeping in mind that it will never improve the biological structure of the population as a whole’.⁵⁴

Sanitary reform and curative care were relevant for currently living individuals. That did not mean they were as such bad, but it did mean that eugenic measures were required to maintain the future population’s hereditary health. Johannes van Loghem (1878–1968), professor of public health and leading figure of the interwar sanitary reform movement in the Netherlands, conceptualised eugenics in his 1935 textbook on public health as a complementary and integral part of public health in similar terms as Hermann Werner Siemens had done earlier. Van Loghem agreed with Siemens that sanitary reform affects the individual human or the human as a population member. Still, it would never improve the hereditary health of the future population: ‘Hygienic theory concerns the developing phenotype solely: it creates favourable conditions for the reaction between genotype and the environment so that the individual can employ its hereditary disposition to the fullest’. In addition to these endeavours, Van Loghem stated in the textbook that sold over 10,000 copies and educated several generations of Dutch medical students,⁵⁵ ‘only eugenics interferes with the genotype, materialised in inherited factors’.⁵⁶ Individuals of the same species have, according to van Loghem, broadly the same genotypic constitution. But within the human population, there are identifiable differences. ‘Eugenics concentrates on the potential harm that undesired deviation can do’.⁵⁷ Hereditary diseases were regarded as the most critical unwanted deviations; left unchecked, they could eventually lead to degeneration. According to Frank Wibaut, these diseases were the manifestation of hereditary disposition under the influence of the environment. Therefore, a fruitful collaboration between eugenics and the medical domain required a division of labour: ‘Whereas eugenics focuses on the hereditary disposition, the rest of medicine aims to positively alter the external factors that direct the development of the disease’, Wibaut stated.⁵⁸

In sum, Dutch authors on applied heredity defined ‘eugenics’ as procrastinating the prevention of degeneration and the preservation of collective health. By doing so, they positioned themselves as a crucial addition to the domain of public health. Eugenicists and sanitary reformers shared the view that public health reform and curative medicine were required to care for living individuals while eugenics was vital in preventing degeneration from maintaining the health of the future population. But how to do so? To understand how Dutch eugenicists envisioned the concrete contribution an application of their research program could make, it is helpful to first examine how they rendered this division of labour within the domain of public health conceptually plausible during the 1930s and 1940s. As authors on eugenics perceived their writings as setting the application of heredity theory centre stage, we need to shift focus to the theoretical nitty-gritty of how they shaped and employed the concept of ‘heredity’ to legitimise the relationship between public health reform and eugenics.⁵⁹

The Conceptual Toolkit of Heredity

For most of the first half of the twentieth century, the meaning of heredity was contested and flexible.⁶⁰ Authors on eugenics were aware of this issue and repeatedly complained that they had to deal with the problem that their scientific definitions competed with a particular ‘popular’ use of the notion. As Groningen professor of genetics, Marius Jacob Sirks wrote in the first edition of his Handboek der Erfelijkheidsleer in 1922, one of the core tasks of a professional hereditary scientist is to distinguish ‘actual heredity’ from what he called ‘apparent heredity’. This analytical endeavour required ‘logical and empirical scrutiny’, and ‘objective judgment’. It should be left to biomedically informed scientists—‘not philosophers and other “soft” academics’.⁶¹ The attempt to strictly demarcate a proper understanding of ‘actual heredity’ not only shows how the concept played a central role in establishing the eugenicist’s professional authority.

After the First World War, Dutch authors on applied heredity theory had been picking up the separation between the individual’s hereditary material and the developing mass of the individual, which historians of biology have called the ‘hardening of heredity’.⁶² Like their international colleagues, Dutch heredity theorists projected this conceptualisation on August Weismann (1834–1915) and his introduction of the ‘germplasm’ as the physiological location of hereditary material in 1893.⁶³ This ‘germ-line’ had a continuous character, meaning that its composition solely depended on the recombination of parental germ-lines. On a cellular level, Weismann considered the lifeless ‘germplasm’ as separated from the living ‘soma’—malleable and changeable by environmental factors. Though the germplasm formed the blueprint for the developing soma, the developing body could not influence hereditary material. In this ‘Weissmanian’ theoretical framework, the genetic material could, in principle, not be altered due to environmental factors.⁶⁴ As a result, the biological process of inheriting traits was explained to be physiologically separated from individual development, which could be influenced by external environmental factors.⁶⁵

Dutch eugenicists remained faithful to Weissman’s conceptual framework for a remarkably long time. Tine Tammes pointed out in her inaugural address as the first Dutch professor in genetics how ‘hereditary factors’ form a continuous, imperishable element of every organism: they are passed on to successive generations unaltered, she argued, independent of any circumstances.

Whether someone generates a vast amount of wealth and climbs the social ladder, or whether someone spends his life in unfavourable circumstances; whether he travels to the North pole or works in the mines, he will pass on the hereditary factors that he obtained from his parents unaltered to his children.⁶⁶

This immortal character of the physiological structure of hereditary factors also formed the theoretical core of Marius Jacob Sirk’s Handboek der Erfelijkheidsleer, published in 1922. In Sirks’ interpretation, Weissman demonstrated that certain parts were separated very early in embryological life, which later formed the origin of future reproductive cells. These parts, Sirks wrote, ‘were turned off during development from embryo to adult life until the moment came that the body was mature enough to be ready for reproduction’.⁶⁷ During copulation, the hereditary material of both parents recombined. According to Sirks, Weissman’s ‘crucial point’ was the continuous chain of hereditary material.

Despite his popularity in the Netherlands, biologists elsewhere began to deem Weissman’s conclusion slightly outdated. The so-called ‘Lamarckist’ perspective claimed that traits acquired during development resulting from environmental influences could be inherited and passed on to the next generations. The possibility of ‘inheriting acquired characteristics’ included the so-called possibility of heritable ‘germ damages’. For a big part, this interpretation was grounded in Auguste Forel’s (1848–1931) writings on ‘Blastophtoria’—a pathology explicitly relating to alcohol, potentially damaging the reproductive cells and hereditary material, thereby causing a degenerate child. Next to alcohol, also syphilis, tuberculosis and heavy metals were considered germ poisons.⁶⁸ The possibility that a degenerate disposition could be caused by exposing the individual to germ poisons implied that collective degeneration resulted from damaging environmental traits. Yet reversely, it also indicated that environmental reform could be enough in preventing degeneration.

The latter interpretation was a bridge too far for Dutch eugenicists. In the early 1920s, Dutch authors on heredity either did not discuss heritable germ damages, problematised its empirical justification, or framed the subject as a case of ‘apparent heredity’.⁶⁹ In his 1927 textbook on heredity theory, the Dutch eugenicist Johannes Waardenburg accepted the damaging effect of alcohol but argued that it could only harm the hereditary material in the embryological phase of development.⁷⁰ Marianne van Herwerden agreed with Waardenburg in her 1929 textbook and concluded from the fact that poisons such as alcohol only damaged the hereditary material during development, that ‘germ damages’ had to be considered an example of ‘apparent heredity’. After all, Waardenburg and van Herwerden considered it doubtful that the germplasm damages could be inherited.⁷¹

Even the famous American fruit fly experiments aiming to show how external forces could change genetic mutations could not convince Dutch eugenicists.⁷² Even though these experiments were already published in 1914, it took until the mid-1930s to crystallise in Dutch textbooks on heredity. In contrast to the first edition of 1922, Sirks’s second edition of Handbook der Erfelijkheidsleer—published in 1933—dealt quite extensively with the observed hereditary changes of the genotype. Sirks admitted in a new chapter on ‘germ damages’ that experiments with Drosophila under the influence of irradiation indeed suggest the possibility of ‘gene mutations’. He concluded that ‘the work of Muller’s school convincingly showed how radiation plays a significant role in changing the genotypic structure of the reproductive cells of this individual’. However, Sirks was critical of the idea that the Drosophila experiments could be interpreted as evidence for the inheritability of acquired characteristics. Although alterations in the gene structure might be observable, he considered this interpretation wrong. Other Dutch eugenicists emphasised that ‘the observed phenomena should not be regarded as caused by the direct influence of irradiation on the genotype. Instead, they should be explained by selecting certain self-derived genotypic mutations, which have a bigger chance of viability in an unnatural environment’.⁷³

Sirks’s interpretation of germ damages reflects a broader consensus among Dutch authors on heredity at the end of the 1940s. They had to admit that specific influences could damage the hereditary material and that these ‘traits’ were heritable. Still, Dutch geneticists increasingly emphasised the special status of these ‘real’ hereditary alterations. In contrast, the damaging capacity of alcohol was increasingly problematised and categorised as an example of ‘apparent heredity’. The Catholic physician Johannes Schulte stated, for instance, in 1938 that it ‘is now clear that many of the apparent hereditary alterations in the germplasm have to be explained in terms of an already existing genetic defect’.⁷⁴ In other words, Dutch eugenicists explained American experimental results suggesting that external factors could alter the hereditary material in terms of pre-existing genetic defects caused by parental recombination of the germ-line.

Dutch eugenicists stuck to distinguishing the hereditary material and the developing body. They kept emphasising that the germ-line formed the blueprint for physical development and that environmental factors could not alter the hereditary material. Notably, the environment had no improving or degenerating effect on future generations—its influence was restricted to the individual ‘soma’. Indeed, Dutch eugenicists followed international trends in biology by explaining heredity in such a ‘hard’ manner.⁷⁵ Crucially, however, Dutch eugenicists dismissed genetic determinism.⁷⁶ They generally admitted that both the heredity material (‘nature’) and environmental influences (‘nurture’) played an essential role in individual development. Tine Tammes, for instance, argued in 1919 that although an organism has a fixed hereditary basis, its characteristics are very much plastic; they respond, to a large extent, to environmental circumstances. ‘What we observe as an individual organism is only one of the many probable outcomes—it is the result of the culmination of hereditary disposition and the circumstances in which an organism lives. What we observe is not more than one of the many possible phenotypes’.⁷⁷ Tammes explained that the phenotype was not determined by its genotypic blueprint; nature did not necessarily prevail over nurture. Social democrat Gerrit Pieter Frets, one of the leading Dutch eugenicists specialising in biometrics and heredity, pondered poetically in his 1935 textbook on heredity theory that ‘all that is has its phenotype. This is the share of the environment in the appearance of the individual. Just as living beings “exist” in every moment of their lives, they also exist under environmental influences. Nutrition, housing, light, external causes for disease and other damaging factors impact the developing individual’.⁷⁸

Another great example of the Dutch caution with genetic determinism is Sirk’s inaugural lecture as professor of Genetics—as the successor of the earlier mentioned Tine Tammes—in 1937. His lecture, called (literally translated) ‘the threefold covenant in biology’, elaborated on ‘core genes’, ‘germplasm’ and the ‘environment’ as the three fundamental building blocks of genetics. ‘Usually’, Sirks stated, ‘the politics of giving and taking conducted between the three participants in the covenant of biology can be compared to state diplomacy’. The basic principles of the covenant are ‘negotiated and established by the hereditary disposition in the genes, and the germplasm; the precise editorial proceedings are the task of the environment’. That is how every individual organism ‘originated due to a compromise between the three spheres of biology’, Sirks concluded, ‘humans are no different in that respect’.⁷⁹

The picture arising from how Dutch eugenicists dealt with biological questions on trait transmission and development throughout the 1930s and 1940s is quite remarkable from an international perspective. On the one hand, Dutch eugenicists remained faithful to a Weismannian physiological separation of the hereditary material (or ‘germ-line’) and the developing material (or ‘soma’). They continued to downplay the ‘Lamarckian’ possibility of inheriting acquired characteristics until well into the late 1930s. On the other hand, they rejected giving priority to either environmental or inherited factors in explanations of individual development. Formulated in conventional analytical terms: in the Netherlands during the interwar years, based on the analytical separation between hereditary transmission and development, the ‘hardening of hereditarianism’ did not result in genetic determinism. As I will show next, this combination of a ‘hard’ conception of heredity with a heavy emphasis on the influence of ‘nurture’ formed the conceptual pillars of how Dutch eugenicists claimed to solve their carefully constructed public health problem: that of degeneration as the undesired consequence of civilisation.

Understanding and Solving Degeneration

Dutch eugenicists conceptualised ‘degeneration’ as a hereditary condition. Johannes Waardenburg, for example, emphasised in his 1927 textbook De Biologische Achtergrond van aanleg, milieu en opvoeding that only traits with a hereditary basis and transmitted to subsequent generations through reproduction culminate in a degenerating society. Waardenburg employed the now familiar distinction between ‘actual’ and ‘apparent’ heredity to identify these traits. ‘In post-war periods of decay’, Waardenburg wrote, ‘when moral consciousness declines, criminality rises and swing dancing proliferates, social reformers are not necessarily confronted with degeneration: what they observe are, for the most part, cases of “apparent heredity”’. Waardenburg called the social problems reformers were confronted with during periods of decay ‘decadence’, which was not caused by hereditary factors but by environmental influences.⁸⁰ The issue of degeneration belonged to the eugenicists as they were the only ones able to investigate which characteristics were inheritable and which were not. This was a difficult task because the number of ‘real’ examples of degeneration was perceived to be limited. According to Waardenburg, only knowledge of eugenics enabled one to scientifically investigate the characteristics that were ‘actually’ hereditary and eventually led to degeneration. This was a crucial, but not the final step. Once proper environmental conditions for optimal development had been guaranteed by public health reform, eugenics could preserve population health by investigating the possibilities of reproductive measures.

To further articulate the symbiotic relationship between eugenics and existing public health reform in countering degeneration, Dutch eugenicists employed their dismissal of heritable acquired characteristics. One of the most confident anti-‘Lamarckian’ voices was Hermann Werner Siemens. He introduced the conceptual distinction between ‘paratype’, the soma of the developing individual, and ‘idiotype’, the hereditary disposition. Based on the dominant Weismannian framework centred around the continuity of the germplasm, Siemens argued that environmental influences could only affect the paratype during development.⁸¹ This analytical distinction and the restricted influence of the environment compelled Siemens—to his frustration—to address the question ‘of the hereditability of acquired characteristics’, in which ‘scientific laymen’ appeared to believe ‘so desperately’. Siemens did understand why Lamarckism was so attractive among other public health reformers. ‘It is tempting to imagine that public health reform not only improves the lives of currently living humans’, Siemens argued, ‘but at the same time also future lives will be improved’. He regarded such optimism as ‘healthy’ but unjustified and unscientific. Beliefs in the hereditability of acquired characteristics certainly played ‘a role in the world view and social politics of many biologically uneducated’, Siemens wrote, ‘but it is nothing more than just proof of an annoying lack of insight into the basic concepts of heredity’.⁸²

Based on the Weismannian distinction between hereditary transmission and development, Dutch eugenicists did not understand hereditary degeneration as caused by a toxic environment acting on an individual but by the reproduction of individuals who already had a degenerate hereditary disposition. However, because individual development was neither determined by nature nor by nurture, environmental reform could help someone with a corrupt constitution to nevertheless employ its potential to the fullest. Simultaneously, it could not improve the hereditary material that all individuals of a population shared. In line with the analytical distinction of development and heredity, Dutch eugenicists generally envisioned two complementary directions of public health intervention in response to degeneration: improving individual developmental health and the long-term hereditary health of the population.

This symbiosis between individual and population-oriented public health reform was already apparent in Tine Tammes’s inaugural lecture as the first professor of genetics in 1919. ‘Society’, she metaphorically sketched, ‘has to be understood as an unprocessed, unevenly fertilised field on which the seed has been sown without any care’. As a result, Tammes concluded, ‘we cannot judge the hereditary value of individuals who grow up there’.⁸³ Therefore, reproductive measures to prevent degeneration made sense if and only if environmental conditions were optimal. Otherwise, it was impossible to distinguish characteristics caused by the individual’s biological nature from those caused by environmental influence on development. According to Dutch eugenicists, a public health approach aiming at environmental improvement to secure developmental health did not compete with a eugenic approach trying to preserve long-term population health through reproductive measures. In other words, the necessary and righteous improvement of public health requires eugenics.

This interdependency worked both ways. Dutch eugenicists reasoned that in order to prevent degeneration, environmental improvement was required for eugenics. This perspective can already be found at the beginning of the interwar period in Tine Tammes’s inaugural lecture on ‘Heredity and Society’. Tammes put all her hope in the idea that better developmental conditions fostered a sense of social responsibility:

Among the circumstances that influence the development of the individual constitution following his hereditary factors, I also count the individual ‘Will’ as such a circumstance. This ‘Will’, nurtured by education, awareness, and humanitarian sensibilities, or controlled by self-interest and ambition, makes the individual feel responsible for limiting the spread of degenerate hereditary factors he or she possesses.⁸⁴

Dutch eugenicists dismissed the German sterilisation laws because they did not consider the importance of environmental conditions to enable every individual to develop its ideal constitution.⁸⁵ They generally argued that although these improvements affected the developing individual, they did not influence the hereditary material of these individuals. This meant only those traits could be considered hereditary if they were still visible in an ideal environment, and their predecessors had the same degenerate constitution. As an explanation for this position, Dutch eugenicists metaphorically stated that every individual was just one link in the chain of a population. The chain stood for the hereditary material; its direction was determined through the reproductive decisions of every individual. Hence, individual reproduction directly influenced the developmental starting points of the members of the future population. With their emphasis on ‘social responsibility’, Dutch eugenicists underlined that individuals were part of society as a whole. Earlier generations determined their heritable starting point for development—not by biological, but by moral selection.

With their connection between environmental improvement, individual development and social responsibility, Dutch eugenicists succeeded in finding their place within the domain of public health. Dutch eugenicists argued that an optimal context for development had to be created to effectively prevent degeneration and maintain public health. Only then degenerate individuals might be identified and enlightened to restrain themselves from reproducing. Dutch eugenicists related in a similar way to ‘positive eugenics’, which was instead focussed on selectively encouraging individuals with desired characteristics to reproduce. These desirable individuals could only be identified in an optimal environment. From that perspective, pronatalist policies would encourage individuals without clearly understanding which traits were’ actually’ hereditary, and the increase of undesirable characteristics could have counter-selective consequences.⁸⁶

For Dutch eugenicists, population health was a matter of social and moral responsibility at the level of the individual. For Tammes, this individual ‘Will’ provided the reason for hope and optimism. If the individual lives his life in an optimal environment, receives proper eugenic education and is raised well, they would be able to develop a sense of social responsibility for the health of the population. As a result, the autonomous citizen would independently decide not to reproduce or even undergo sterilisation voluntarily.⁸⁷ In his 1927 textbook on the biological origins of nurture, heredity and the environment, Johannes Waardenburg stated that individuals could develop a certain sense of ‘social responsibility’ and ‘solidarity with future generations’ once the individual is raised and educated in a healthy environment.⁸⁸ The attention to social responsibility for the future health of the population among Dutch eugenicists increased in the rest of the interwar years.⁸⁹ Marianne van Herwerden, for instance, argued in the second edition of her textbook on heredity and eugenics that the most critical lesson from heredity theory concerned ‘that every individual human is just a link in the chain of the human population and that every single human is responsible for the future of mankind’.⁹⁰ This position explains why Van Herwerden portrayed eugenics ‘not solely as a research subject,’ but as a ‘worldview, in which humans are currently living, bear the responsibility for the mental and physical health of future generations’.⁹¹

In contrast to how Dutch eugenicists liked to present themselves, the picture arising from these positions is far from neutral. The way in which Dutch eugenicists conceptualised ‘heredity’ implied that environmental improvement was a precondition for applying eugenics research. They believed that proper education on heredity theory encouraged an individual’s sense of responsibility for public health and prevention of collective degeneration. As a result, Dutch eugenicists insisted, individuals would eventually be willing to subject themselves to reproductive measures for the greater good. Gerrit Frets stated even quite explicitly that ‘the eugenic ideal envisions a society in which every individual develops the ability to fully deploy its potential. It envisages a society respecting everyone’s opinion, and in which every individual is willing to cooperate in the interest of the whole population’.⁹² This emphasis on autonomous citizenship fitted the Dutch interwar liberal-confessional political culture in which ‘the individual did not exist for the sake of the state’ and eugenic policy was considered an inappropriate topic in Dutch national parliament.⁹³

Conclusion

This paper explained the coexistence of concern about hereditary degeneration and opposition to eugenic policies such as sterilisation in Dutch eugenic discourse. Dutch authors on ‘eugenics’ and ‘applied hereditary theory’ positioned themselves within the domain of public health through their organisations and academic positions, and legitimised this place by framing ‘eugenics’ as a vital component of health reform. As curative medicine and sanitary reformers primarily affected the lives of currently living individuals, eugenicists focussed on the hereditary health of the future population. They rendered this division of labour to be conceptually plausible by sticking to a ‘Weissmanian’ distinction between the developing body that was to a huge degree affected by the environment on the one hand, and the hereditary material that only changed through recombination without being altered by external forces on the other hand. This conceptualisation of heredity served as a two-way street. On the one hand, it justified rejecting ‘Lamarckist’ perspectives arguing that improving environmental conditions repaired hereditary defects. On the other hand, this Weissmanian distinction enforced a rejection of genetic determinism. In the eyes of Dutch eugenicists, environmental factors and inherited predisposition were both important. This conceptual constellation enabled Dutch eugenicists to claim that improving the health of individuals was necessary, but its impact was limited to the short term. After all, eugenic knowledge was required to prevent collective degeneration. Consistent with their criticism of sterilisation policies, Dutch eugenicists emphasised the need for optimising developmental conditions, which not only aided in determining defects that were actually heredity. The combination of proper (eugenic) education and a healthy environment would also stimulate individuals to behave socially responsibly and restrain from reproducing or undergoing voluntary sterilisation. From this perspective, eugenicists regarded reproductive legislation to be redundant.

This interpretation not necessarily revises but contributes to Jan Noordman’s externalist explanation of the absence of eugenic policies in the Netherlands. It is true that Dutch politicians considered top-down state interference with reproduction at odds with liberal-confessional values and the ideal of autonomous citizenship.⁹⁴ In this article, subsequently, I have explained how Dutch eugenic authors did not contrast but aligned with the interwar political climate. Cautiousness with reproductive intervention formed professionally, conceptually and politically one of the pillars of what Dutch authors on applied heredity theory understood as eugenics proper.

This paper focussed on the writings of Dutch authors on applied heredity theory themselves. In his recent overview on the historiography of eugenics, however, Paul Weindling encourages to ‘look beyond discourse’ and shift our focus to social processes as ‘the construction of welfare institutions and practices’.⁹⁵ Weindling’s call certainly applies to the Netherlands as well. The critical stance toward eugenic legislation among Dutch politicians and eugenicists does not mean that reproductive intervention did not happen. In his research on therapeutic castration, Theo van der Meer for instance showed that ‘sex offenders’ were medicalised as homosexuals during hospitalisation through eugenic categories and were forced to undergo (illegal) ‘voluntary sterilisation’ by their doctors to prevent future social harm.⁹⁶ Examples like these show that—certainly for the Netherlands—more research is required to determine whether these cases are exceptional and assess the practical implications of eugenics as being located within the domain of public health for ‘degenerate’ individuals themselves. Yet, this paper reminds us that we should not forget to analyse the conceptual struggles among historical actors for countries that received less international attention from historians. Having done so by explaining the tight relationship between Dutch eugenics and public health, I hope to have made a contribution to the recent trend to analyse eugenics as a transnational phenomenon and enable other historians to include the Netherlands in their comparative accounts.

Acknowledgements

I consider this essay the result of research and education during my MSc in history and philosophy of science at Utrecht University, and my time as a recognised student at the Oxford Centre for History of Science, Medicine and Technology. I am grateful for the feedback from Frank Huisman, Stephen Snelders, Bert Theunissen, and John Lidwell-Durnin on drafts of the MSc thesis chapter that formed the basis of this essay. Additionally, I would like to thank my great PhD supervisors Ralf Futselaar, Timo Bolt, and especially Noortje Jacobs for their suggestions, questions, and comments on earlier drafts of this essay. Finally, I would like to thank the anonymous jurors of the Roy Porter Student Essay Prize and three anonymous reviewers for their invaluable suggestions.

Funding

I have not received funding for research conducted for this essay.

Footnotes