Rats,stress and the built environment

Introduction

In his Pulitzer Prize-winning book, So Human an Animal, the biologist and public intellectual René Dubos reflected: ‘It is perhaps symbolic that rats appear to be the only mammals that have increased in numbers during the past century as much as men’ (1968: 188). For Dubos, the rat was a symbol of the ecological destruction wreaked by an ever-increasing human population. Long associated with the twin processes of explosive demography and urbanization, it is a habitual resident of the city, thriving in close proximity to humans. Jonathan Burt (2006: 149) observes: ‘Because the rat is so bound up with ideas of mass and number it seems to be a totemic animal for the modern world’. It is also bound up with a range of undesirable social behaviours associated with the city and the crowd. The immunologist Hans Zinsser (1935: 195, 208) described the rat as ‘amazingly human’ – omnivorous, adaptable, irresponsibly fecund and ‘utterly destructive of other forms of life’:

This apparent similarity between rat and human was more than symbolic; it was analogical, to be found in physiology, behaviour and social structure. While the rat may have been despised, it was not without its uses. It also served as one of the leading experimental animals of the 20th century, its apparent perspicacity proving particularly attractive to behavioural scientists. For this reason, it has also been of interest to historians and philosophers of science. Here, however, the animal of interest is often one that has been standardized, purified, portioned and packaged (Shapiro, 2002). For Karin Knorr Cetina (1999: 27), the laboratory dispenses with treating the object ‘as’ and ‘where’ it is in nature, and ‘when it happens’ in terms of natural cycles of occurrence. Robert Kohler similarly argues that the flies, rats, mice and weeds which ‘lived in an irregular, undomesticated relation with humankind’, became transformed when they crossed the threshold from the wild to the new ‘ecosystem’ of the experimental laboratory, becoming ‘physically reconstructed and adapted to experimental uses’ (Kohler, 1993: 282). Kohler argues that the laboratory draws its credibility from the idea of placelessness, its spaces ‘neutral stages’, and the animals and plants which inhabit them ‘passive guests’: ‘The variability and unexpected occurrences of nature have no place in labs’ (Kohler, 2002: 6–7).

Yet Kohler also argues (1993: 282) that it is necessary to carefully examine the relationship between experimenter and animal as the scientist’s control is never complete. Experimental organisms are ‘active players’ with the ‘capacity to change and frustrate’. Rachel Ankeny and Sabina Leonelli (2011: 315) argue that experimental organisms have a ‘hybrid status’: ‘they are systems that have been engineered and modified’ for specific uses, and ‘at the same time they remain largely mysterious products of millennia of evolution, whose behaviors, structures, and physiology are for the most part still relatively ill-understood by scientists’ (cf. Birke et al., 2007). It is this dual existence as both ‘artefact’ and ‘sample of nature’ which makes them so productive – continuously generating new scientific questions while allowing for their controlled investigation (Leonelli, 2007). The rat – as ‘wild’, ‘urban’ and ‘object’ of science – is particularly well positioned in this respect. In our story, the rat was, quite literally, a ‘sample of nature’, taken from its habitat (the city’s backyards) and (re)introduced into the laboratory, raising significant questions regarding the applications of the animal laboratory to the study and well-being of humankind. ¹ Examining this continued interest in the wild rat, and further, the use of laboratory environments that encourage freedom of movement, interaction and expression, allows us to critically examine some of the ways in which boundaries between natural and human, civilization and wilderness, laboratory and field, were not only constructed, but transgressed. We are also encouraged to move beyond the confines of the biomedical, physiological and genetic laboratory, focusing much-needed attention on the relevance of experimental animals to social medicine and the behavioural and population sciences, and relating the history of science and medicine to environmental, urban and design history's focus on place and physical and material factors.

This article will focus on a group of scientists charged with controlling the rat in the urban environment. The rodent control project at Johns Hopkins University employed the psycho-biologist Curt Richter as its first director from 1942 to 1944; the animal ecologist David E. Davis as director from 1945 until its termination in 1952; and the animal ecologist cum psychologist, John B. Calhoun, as a researcher from 1946 until 1949. Rodent control was integral to realizing a sanitary and ordered urban environment – one rationally planned through science and technology. There is a reason, argues the sociologist Zygmunt Bauman, that ‘utopias chose architecture and urban planning as both the vehicle and the master-metaphor of the perfect world that would know of no misfits and hence of no disorder’ (Bauman, 1992: xv). ² Bauman sees the city as embodying Ernest Gellner’s characterization of modernity as a ‘gardening culture’ – sustained ‘by literary and by specialized personnel’; quite unlike the earlier ‘wild cultures’ which ‘reproduce themselves from generation to generation without conscious design, supervision, surveillance or special nutrition’ (Gellner, 1983: 50; quoted in Bauman 1987: 51).

In order to devise new and more effective methods of controlling the ‘wild’ rat, it was necessary to understand its behaviour and its needs. To do so, the scientists turned to the laboratory, a similarly sanitary, segregated and geometrically ordered space. Indeed, laboratory design embodies a distinctly modernist architectural ethic, scientists based at the famed Wistar Institute describing, for example, how the construction of a laboratory of ‘brick, concrete, steel, and glass’ offered ‘less harbor for dirt and vermin if properly put together … no space unfit for human habitation is desirable for an albino-rat colony’ (quoted in Lindsey, 1979: 7). As both Bauman and Kohler recognize, the spaces of the laboratory and those of the city centre feed into one another. They are both idealized as ‘placeless places’ – increasingly generic, universal, predictable, repetitive, devoid of quirks and personality (Kohler, 2002: 9). The laboratory is designed to preclude ‘practices of place … their arrangements do not intrude in the analysis of the experiments, unless something has gone badly wrong’ (ibid.: 213). The control offered by the modern laboratory confers its authority; so much so that elements of laboratory practices have had to be assimilated into science in the field. While Kohler’s analysis of the relationship between lab and field is built upon in this article, Gregg Mitman (2003) notes that the border-crossing is all one way – the methods, skills and related paraphernalia of the laboratory worker, which Kohler (2002: 18) imagines as a Roman cosmopolite, transferred to the ‘barbarian’ field-worker. Reminiscent of Bauman, an unkempt and unpredictable wilderness is cultivated by an expanding and authoritarian gardening culture. Kohler misses the opportunity to examine the way in which the practices of the field transform those of the laboratory, and thus continues ‘to write the history of twentieth-century biology from the perspective of the Roman wandering in the barbarian hinterland; the neighbors are noble savages, but savages nonetheless’ (Mitman, 2003: 599–600).

In this article, we will see how the scientists of rodent control continually shuttled between laboratory and field, the practices in one continuously informing the other. Richter may well have designed his laboratory spaces to be repetitive, neutral and passive, allowing him to design new and improved technologies (poisons) to eradicate the urban rat. Yet, as he was now able to compare the ‘free’ wild animal with its incarcerated cousin, he came to recognize that the intrusion of laboratory practices into the lives of its inhabitants (and the data they produced) was not precluded; it was the norm. This did not, however, undermine his existing experimental practices, so much as redefine them. The focusing on the problems of ‘stress’ among his laboratory animals meant that they became most productive models, not of nature, but of a modern human moulded by an urban environment of indulgence and banality, and even the modern scientists, too often governed by their elaborate, predictable and monotonous experimental designs.

Boundaries were only further transgressed as the project became increasingly focused on methods of environmental control. Drawing upon Kohler’s (2002) notion of a ‘hybrid’ space, we shall see how the ecologists under David E. Davis did indeed transfer laboratory practices into the field, but they also transferred elements of the wilderness into the laboratory, providing more naturalistic methods, objects and spaces. The subject of stress again functioned as an important ‘transactional construct’ (Evans, 1982: 1), but was here extended beyond a regulatory mechanism of the individual body, to the population as a whole. While it was not possible to completely eradicate the rat, it was possible to enrol stress as an agent of population control by altering environmental parameters. As Bauman argues, the condition of purity is an ideal never to be realized. As much as the gardener seeks to eradicate those things that are ‘out of place’ – ‘to burn them out, poison them, shatter them in pieces’ – they are often ‘mobile things’, continuously revealing our schemes of order and control as artificial, fragile, shaky and inevitably limited.

The city also serves as a hotbed of uncertainty, an endless source of surprise, disorder and danger (Bauman, 2003). Failures to realize a rationally ordered do not, however, result in the abandonment of the gardening ideal. They continuously drive it forward. Through ecological methods of rodent control, Davis also saw an opportunity to promote the organization of the city through modernist architectural design.

Finally, we shall see how Calhoun combined elements of both Richter’s and Davis’s experimental systems and their respective visions of science in the service of the city. Like Richter, the focus was the laboratory as a garden state, one which had a significant and potentially detrimental impact on the lives of its inhabitants. He was even more explicit in making connections between the animal laboratory and the urban environment, designing a series of so-called ‘rat cities’. Yet, like Davis, the focus was not on the individual animal isolated in a pen, but on an interactive and dynamic environment that drew upon his understanding of the animal in nature. The result would be an influential synthesis of psychology and ecology that privileged the animal laboratory as a site for understanding, predicting and ameliorating the stress-related pathologies associated with urban living. As Dubos (1968: 91) declared after reflecting on Calhoun’s research: ‘It is true that men are not rats. But the most unpleasant thing about rats in crowded conditions is that they behave so much like many people in crowded human communities.’ ³ Indeed, it is in Calhoun’s laboratory that both the animals and the environment were analysed as complex interactive systems in ways that would prove influential in the social and behavioural sciences and in the planning and design professions. This article will, therefore, be organized around a series of steps by which both the animal and the laboratory environment became models of urban structures and inhabitants, further extending the role of science in the ordering of the city.

Declaring war on the Norway rat (and the welfare state)

Lydia Edwards, an intern at Johns Hopkins Hospital in 1932, had vivid memories of Baltimore’s rats. When on emergency call on Sunday morning, she

The rat served as both symbol and symptom of sickness and degeneration, the prevalence of disease having made Baltimore an attractive site for public health work (Fee, 1991: 178–9). Yet this ‘population laboratory’ (ibid.: 182) for research and practical training now seemed to advertise the remedial failures of Johns Hopkins’ medical and public health specialists. Abel Wolman, chair of the Maryland State Planning Commission and Department of Sanitary Engineering at Johns Hopkins, warned Lowell J. Reed: ‘Deteriorating environment flanking the whole Center will become increasingly objectionable from the standpoint of student, staff and patient use.’ ⁵ Baltimore could serve as a great experiment in public health and planning, focused on the interrelated programmes of slum clearance and rodent control.

The project of rodent control was established at Johns Hopkins Medical School in 1942. It was not only supported by the City of Baltimore, but by the Office of Scientific Research and Development, the destruction of foodstuffs and spread of disease considered more significant at a time of war. At Johns Hopkins there was also one of the world’s leading animal experimentalists, the physiologist and psychologist Curt P. Richter. Inheriting his laboratory from the behaviourist John B. Watson, Richter inverted his use of the animal. On being presented with a cage full of Wistar rats by Watson, Richter did not seek to directly control their activities; he allowed them to express their innate behaviour to him, seeking to uncover how ‘the rat “works”‘ (Richter, quoted in Schulkin, 2007: 326). Dividing them into individual cages of his own design, Richter began a lifelong study of internal, spontaneous and biologically determined rhythms. As can be seen in the photograph of his laboratory, this is a highly organized and industrialized space, row upon row of identical cages providing the animals with food, water, warmth, and activity wheels. While these ‘analytic’ animals were embedded in the mechanical devices of the laboratory (Latour and Woolgar, 1979; Lynch, 1988), they also served as their own controls, automatically generating reams of psychobiological data regarding their innate day-to-day behaviour. ⁶ This data was then represented and monitored through charts, tables and graphs unique to each animal, and placed on each individual cage like a patient’s chart on a hospital bed.

As Paul Rozin (1976: xix) argues, Richter’s experiments were those of a classical physiologist – powerful, dramatic, focused on the individual organism, and eschewing all but the most simple of statistical measures. Building upon Claude Bernard’s and Walter Cannon’s physical systems, Richter argued that biologically motivated behaviour was also essential to the organism – a homeostatic regulatory mechanism that corrected instability within and between the internal requirements of the body and its environment. He dedicated himself to the study of behavioural homeostasis, revealing the ‘wisdom of the body’ in selecting the necessary foods for survival. Thus adrenalectomy led to an increased intake of salt, the removal of the parathyroid glands to an increased intake of calcium (Richter, 1942: 66).

Having studied how the homeostatic mechanisms of the body ensured its survival, he now sought to ‘trick the rats into eating substances that will destroy them’; and ‘war was declared on the Norway rat’. ⁷ This was a war Richter was confident of winning, and with the discovery that phenyl thiourea was highly toxic to rats, he contributed a new more effective poison: ‘with our technique and a single treatment with ANTU, a rat population can be struck down within a few days’ (Richter, 1968: 408). ⁸ Combined with improved methods of baiting, the project quickly expanded from a trial of 8 blocks, to well over 5,000 by the end of 1944. There were ‘Rodent Control’ offices established in City Hall and a sub-department established in the Department of Public Works (ibid.).

Richter’s belief in humanity’s ability to control the rat through a technological fix proved optimistic, and the focus shifted to more ecological approaches to rodent control. Having once described himself as a ‘reluctant rat-catcher’, Richter seems to have been happy to turn his attention to a series of problems that had emerged from the rodent control project. As his approach had always relied on the acts and choices of the animal (within a confined space), he was well prepared for identifying further uses for the laboratory rat’s wild cousin, which he saw as ‘validly representing the completely wild animal in its free state’ (1950: 42). He was struck by its dissimilarity to the lab animal. The wild rat was physically slighter and a less successful breeder, reflected in the smaller size of its reproductive organs. Yet it outstripped the albino in terms of bone density and the size of kidney, adrenal gland, liver and brain. There were also differences in behaviour. The wild rat was suspicious of new foodstuffs, and would even die through starvation in captivity (Richter, 1950). In a so-called ‘fighting chamber’, where rats were induced into combat through electric shocks, the wild variety was shown to be much more aggressive and did not exhaust its adrenal glands of necessary lipids and ascorbic acid (Richter, 1952: 277). Richter concluded that the wild rat was a fundamentally different animal from the ‘domesticated’ strain. While the former were ‘normal rats’, intelligent, independent, even ferocious, ‘having fought their way in the streets and alleys’ (Richter), ⁹ the material conditions of the laboratory and the technical requirements of the scientist had inadvertently selected for a fertile, passive, dull animal, happy to be handled and bred, comfortable in its ‘luxurious’ laboratory cage (Richter, 1950: 20).

While the wild rat clearly suffered when confined in the laboratory, the domesticated was less capable of coping with stress due to smaller and less active adrenals. Richter even suggested that the ‘diseases of adaptation’ reported by Hans Selye were ‘simply an indication that the domesticated rat has an inadequate equipment for meeting stress’ (1950: 43). Richter was raising serious questions as to the uses of standardized laboratory animals for understanding natural biological systems, and his descriptions of a degenerate animal encouraged much reflection in the biological and behavioural sciences. ¹⁰ For some scientists, the albino rat now seemed an ‘indefensible choice’ for the study of nature: ‘It is at least a waste of time, if not outright folly, to experiment upon the degenerate remains of what is available intact in other animals’ (Lockard, 1968: 739). It was suggested that even an ‘idiot’ rat could flourish in the laboratory environment, resulting in a relaxation of selection pressure (Robinson, 1965: 514), while another scientist described laboratory varieties as ‘convenient vegetalized strains’ (Kavanau, 1964: 490). ¹¹

Yet for Richter, the albino rat still had an important role in science precisely because of its degeneracy. The laboratory rat was a model for modern humans. In so doing, Richter was able to revise, rather than abandon, his belief in its uses as an experimental animal, while simultaneously promoting his holistic approach: ‘If someone were to give me the power to create an animal most useful for all types of studies on problems concerned directly or indirectly with human welfare, I could not possibly improve on the Norway rat’ (Richter, 1968: 403). The wild rat represented ‘primitive’ man, sharing his day-to-day struggles that ensured ‘physical strength, endurance and aggressiveness were at a premium’ (Richter, 1952: 273).

Richter’s reflections on the domesticated animal, and the laboratory in which it lived, functioned as a critique of modern society. For Richter (1952: 283), the direction of social security in the modern state had been ably described by Orwell: ‘man’s every movement and even thoughts are observed and directed through a two way television arrangement … man’s life in 1984 closely resembles that of our domesticated Norway rat – “happily” living out its caged existence’. With the realization of a welfare state where ‘the good things of life are generally available’, the ‘less strong, less vigorous individuals’ were protected and allowed to propagate their numbers (Richter, 1959: 18, 23). The result was a rise of stress-related illnesses such as asthma, arthritis, skin and arterial ailments, and a range of mental diseases.

The rat also served as a means of expressing dissatisfaction with the scientific establishment. The fact that Richter was so eclectic and unconventional in his scientific practice meant that he relied on short-term grants. He found the endless stream of grant applications and research reports arduous and confusing, and his conclusions often seem dislocated and occasionally overstated. ¹² He used his research with the wild rat to express controversial eugenic ideals, resulting, unsurprisingly, in a short but intense barrage of criticism. ¹³ Robert Morison of the Rockefeller Foundation, who had once been intrigued by ‘the challenging sociological and physiological speculations to be derived’, ¹⁴ now reported him to be ‘over enthusiastic in analogizing man with the domesticated rat’. ¹⁵ The Rockefeller Foundation decided against providing him with long-term support, and various grants from the Office of Naval Research, the National Research Council and the National Institutes of Health were short-lived. ¹⁶

What Richter sought was freedom from interference, and his analysis of the wild rat mirrored his personal and scientific style: aggressive, self-taught, resourceful, creative, thoroughly independent, a ‘tinkerer’ whose breakthroughs often came from chance observations (Rozin, 1976: xviii–xix; Schulkin, 2005: 137). Indeed, the language used by his one-time students to describe him is illuminating: a ‘loner’, a ‘hunter’ with a ‘rugged sense about him’, ‘fearless in the laboratory’ in his dealings with wild rats, even a man of the wild West (Schulkin, 2005: 8, 86, 148). He took great pride in his ability to understand and handle the various animals that he studied, his character chiming with Kohler’s description of the field naturalist as a frontier individualist. Jay Schulkin (2005: 114) writes: ‘Richter was an adventurous spirit; he grew up in the outdoors’, and he noted the quotation hanging in Richter’s laboratory, attributed to the experimental physiologist François Magendie: ‘I compare myself to a scavenger; with my book in my hand and my pack on my back, I go about the domain of science, picking up what I can find’ (Schulkin, 2005: 116). Just as the Aborigines relied on their own wits and energy to survive, great discoveries came not from the detailed and well-organized plans of research teams and committees, but from ‘individual workers, often working in great isolation’, making unpredictable, often puzzling discoveries (Richter, 1953: 91). He called for preference to be shown ‘free, as opposed to design research’ – ‘Let us support the man’ (ibid.). As such, the wild rat was a model for the wild, individualistic and physically impressive early man and the creative and independent scientist; the domesticated a model for the weak and degenerate urbanite, cared for and protected by the welfare state, and modern scientists, funded not on the basis of their own individual creativity, but according to the predictability of increasingly elaborate and overwrought experimental designs.

Nature in the city, the city in nature

Richter had done much to unbox the organism, displaying and analysing its internal workings. Nevertheless, the animal’s behaviour remained, in a sense, secondary. It was determined by physiology, genes and biochemical reactions that ensured homeostasis – a conservative system of negative feedback. Following from his belief in the innateness of behaviour, Richter had isolated the animals in individual cells, dismissing ethological prejudices against such a practice as resulting from a misplaced association with behavioural conditioning:

Richter stabilized and standardized the laboratory environment in order to understand, record and measure the animal’s behaviour. The introduction of the wild rat, however, had led to considerable reflection over the impact of this supposedly neutral space on the experimental animal. With the transfer of the rodent control project to ecologists, these twin elements – the behaviour of the rat in relation to the design of the laboratory – became even more significant. The laboratory cage was not simply used as a space where the rat revealed its inner workings. Behaviour was influenced by the social and physical environment, which, in turn, could determine physiological processes.

As the rodent control project developed, various sanitizers and inspectors were empowered to shame, and later fine, those who did not keep their yards clean and accessible to ensure that the baits were effective (Biehler, 2007; Keiner, 2005). This increasing emphasis on sanitation led to a new interest in the ecology of the rat population in the urban environment as a means of developing a broader and more effective method of control (Keiner, 2005). Population became the new unit of analysis, and complex statistical correlations and curves replaced individual charts and tables. In 1945, with a grant from the International Health Division of the Rockefeller Foundation, the programme was transferred from the Johns Hopkins Medical School to the School of Hygiene and Public Health. Richter was succeeded, very briefly, by his assistant, the ecologist John T. Emlen, Jr, before David E. Davis took control of the retitled Rodent Ecology Project, and was soon joined by a graduate student, John J. Christian, and a research assistant, John B. Calhoun. ¹⁷

The most fundamental problem facing the ecologists was the means of studying the rat in nature. In order to do so, they employed a variety of methods associated with the field practices of ecologists. They traced the movements and lifestyles of rats by tracing their marks and detritus. They took rat censuses through trapping, marking, releasing and recapturing. These methods were aided by Emlen and Richter’s observation that rats rarely left the blocks in which they were born. The city was broken up into ‘natural areas’, each block ‘effectively an island and its rats form a discrete population unit since immigration and emigration of rats is negligible or absent’ (Christian and Davis, 1956: 476). Just as A. J. Lotka’s concept of a ‘closed population’ had, by ignoring migration, provided demographers with a degree of stability and control in understanding human population dynamics, the restricted home range of the animals now allowed the urban environment to be divided into convenient sections or ecological areas. ¹⁸ Lotka’s ‘very natural abstraction’ (1998[1939]: 53), had been made physical and material. Consistent with the field naturalist’s ‘practices of place’, as described by Kohler (2002: 212), the particular arrangement, demarcation and manipulation of a natural space was allowing for controlled investigation and causal analysis. ¹⁹

It also allowed for intervention. While such divisions in the urban landscape had been a source of optimism with regard to a block-by-block approach to poisoning, they also suggested that the control of physical space was the key to controlling rodent dynamics. When releasing a number of alien rats into blocks to study their movements, they were encouraged by the discovery that population density did not increase or remain stable, but decreased (Davis, 1949: 228). Seeking an explanation, Davis turned to competition. The wild rat was, as Richter had argued, a particularly aggressive animal when compared to the laboratory rat, making some strains unsuitable for particular studies of behaviour (Davis, 1966: 73–4). However, this did not mean that the wild animal was less susceptible to stress. Indeed, by isolating his animals in individual cages, Richter had failed to recognize the potentially deleterious consequences of interaction among social animals. John J. Christian (1950, 1964) suggested that increased numbers lead to increased competition over resources, to increased ‘social pressure’ and ‘social strife’. As Davis (1949: 231) described, the introduction of an alien rat into the territory of a ‘happy’ rodent colony where ‘everybody knew who was married to whom, and whose children were whose, and so on’, resulted in considerable ‘psychological turmoil’. The result was physiological breakdown as, once again, stress served as a homeostatic regulatory mechanism – not merely in terms of the individual body, but the population.

Here Christian and Davis were contributing to a long-standing debate within ecology over the role of density-dependent mechanisms in providing some kind of a balance of nature. Competition ensured that a species did not increase its numbers so as to overwhelm its subsistence, and could even explain the famed fluctuations in Arctic lemming populations that had long puzzled ecologists (Chitty, 1996). Davis credited Christian with providing, through his study of the adrenal-pituitary system, a much-needed behavioural and physiological mechanism for such a process. Stress not only served as a means of ‘internal communication’ between hormones, nerves and behavioural commands to maintain a uniform internal medium, but as a mechanism of ‘external communication’, vocal, postural, chemical, tactile – transmitting information about density between individuals to provide demographic equilibrium (Davis, 1987: 827–8; 1966):

Such wisdom of the population came at the cost of the welfare of the individual. Behaviour was not merely determined by the internal requirements of the body, as in Richter’s systems, but by a broader social structure – the roles, hierarchies, culture even, of rodent society. Richter’s interest in the inherited differences between different types of rat was replaced by the ecologist’s interest in ‘social class’, which was determined by an animal’s control of space (Calhoun, 1977: 52). Variation was not a problem that needed to be circumvented through standardized animals and spaces; it was critical to the stability, and management, of a population as a whole.

Understanding the complexities of rodent societies could not, however, be realized by the methods of tracking, mapping and quantification. Furthermore, the urban block was an unstable and variable place, like all field sites, containing highly irregular and ever-changing distributions of physical objects and human actors who often interfered directly with trapping (Calhoun, 1963: 2). It was Calhoun who suggested that they should ‘model the experimental environment after that encountered in the “row house” type of residential area’ (ibid.). Calhoun designed a model environment in a secured quarter-acre pen in some woodland behind his house in Towson, Maryland – ‘a closed universe where a group of rats could set out unmolested to establish their own empire on such an artificial island’. ²⁰ He supplied this small group of rats with food, water and nesting materials, and allowed the population to grow. From a 20-foot observation tower ‘every individual was observed with considerable detail from birth to death’. The social processes of hierarchy, territoriality and competition in generating stress, and thus influencing demography, could now be witnessed directly.

The ecologists were now shuttling continuously between crowded pen and the backyards of Baltimore, both existing as ‘hybrid’ spaces that united the precision and authority of the laboratory with the authenticity of the field. Calhoun argued that scientists needed to use long-term observational studies and experimental approaches in tandem: ‘we must have the courage and foresight to depart from the laboratory in its customarily accepted sense’ and move into the ‘broader laboratory of field situations’; it was then possible to ‘carry back … into the laboratory’ the ‘new problems’ that arise (Calhoun, 1952: 157). The urban block, as population unit and natural area, was neatly transferred into the laboratory, Calhoun’s approach described as a ‘quasi-naturalistic experimental arrangement’ (Gottlieb, 1964: 900). ²¹ Concomitantly, the understanding of processes gained from the laboratory could then be translated back to the ‘wild’, be it city block or territory in the northern tundra. Indeed, the boundaries between city and wilderness were also becoming blurred. Many began to treat nature as, in a sense, urbanized – home ranges, territorial processes and crowding stresses functioning to limit population growth in a wide variety of species and geographical areas (Chitty, 1996). When discussing the exploding Arctic populations of lemmings and jaegers, Paul Sears (1958: 12) noted that such animals ‘do not urbanize well’.

In turn, the laws of nature were applied to urban spaces. Davis equated poisoning with predation. It would only have a temporary effect, as the population would soon return to the capacity determined by the environment (Davis, 1972: 159). It could do so quickly, as by removing the weak and susceptible, one afforded more space, less stress, for the surviving animals to grow and to breed. ²² ‘The biologist’, he argued, ‘must not waste research funds in futile attempts to avoid biological laws’ (Davis, 1971: 170). Instead, he demanded the principles of wildlife management be employed in the city. By removing the rat’s access to food, water and shelter within each city block, the scientist, city planner and public health official would enroll its agency. Further, as the most effective method of ‘rat-proofing’ was to eradicate slum-housing, as Biehler (2007) also argues, the ecological approach would remedy more than just the vermin problem. Davis explained to a journalist, ‘there is no such thing as a rat problem … it is a human problem and a bad housing problem’. ²³ The rodent ecology project would contribute to an even more general programme of public health as had been suggested by Abel Wolman, who now served on the project’s advisory board. As Davis declared:

Stuyvesant Town, a large modernist residential development on the East Side of Manhattan, was proving a successful (if controversial) venture, bringing order to a once impoverished, dilapidated and crime-ridden area. ²⁵ Yet it was the Baltimore Plan, established in 1944 to enforce housing laws and health regulations, which had led the way in slum clearance. For Davis, the reduction in Baltimore’s rat population from 400,000 in 1944 to 40,000 in 1950 resulted from this ‘postwar building and rehabilitation program’. ²⁶ Once again, the rat served as a symbol of the city, as a police officer reportedly described:

Unlike Richter, Davis was very skilled at managing people, time, bureaucracies and funding bodies (Christian, 1995: 491–2). ²⁷ He secured permanent employment at Johns Hopkins in the Department of Parasitology, its new director, Frederick Bang, believing prevention through the manipulation of the environment to be the future of disease control. ²⁸ However, his research had limited influence in the field of human ecology. In order to secure further Rockefeller Foundation funding for the project from 1948, he was requested to explain how his studies would develop a ‘broad fundamental interest. Rat ecology alone will not qualify it.’ ²⁹ The Rockefeller Foundation was reassessing its support of Johns Hopkins, while simultaneously considering the degree to which ‘human ecology’ and ‘population’ would be included in its new programme of public health. ³⁰ Marston Bates, the medical entomologist charged with assessing the foundation’s potential role in this area, was suspicious of Davis’s attempt to extrapolate from animal to human ecology. ³¹ Having given him one final opportunity to outline his ideas, Bates considered the result ‘quite disappointing’: ‘It is probably perfectly good ecology, but I don’t see the broader implications as he has set it up.’ ³²

Davis argued that study of a variety of species in the laboratory and field allowed the ecologist to identify the ‘general principles’ that governed population growth across species. He was working at the meta-level, the forces of reproduction, mortality and migration functioning according to ‘definite laws’. These were reflected in the shape of that favourite instrument of the population biologist – the logistic function; ‘rat curve’ and ‘human curve’ could be mapped onto one another (Davis, 1953: 379). However, Davis was rather detached when it came to politics and policy, speaking of an ‘expectation of applying the principles to human populations eventually’. ³³ In any case, it was ‘not the province of the biologist’ to seek socially acceptable policy or political change, but merely to provide the facts to be applied by others: ‘basically the biological laws will have to be obeyed’ (Davis, 1972: 169). The problems of sanitation, urban rehabilitation and slum clearance ‘are the province of political science and the educator; they are not the province of the biologist’. A report of 1948 contained an oblique reference to a possible study of the Navajo, and he later traced the rise and fall of populations in the Middle Ages: ‘The disturbances, the wars, the litiginousness, and finally, disease were all manifestations of competition and stress’ (Davis, 1986: 264). While having provided an important population perspective in which stress served as a ‘sociopsychological mechanism’ (Christian and Davis, 1956: 475), once again behaviour existed within a deterministic and mechanical model of negative feedback. There was little here to excite those at the Rockefeller Foundation concerned to address the problems of human population growth. It would take the work of his research assistant, John B. Calhoun, to traverse the boundaries between the study and control of urban environments and social behaviour in rats and humans.

Trouble in rat city: The laboratory as an urban space

In his experiments, Calhoun was careful to identify the significance of the relationship between numbers and space. In the quarter-acre pen the population never exceeded 200: ‘The number is particularly instructive when we compare it with the number of rats that might have been raised … had each individual been isolated as a juvenile into two square feet of cage space. … Under such laboratory conditions 5,000 healthy rats might have been reared.’ He even went on to suggest that with a slightly smaller cage of 8 inches a side, ‘50,000 healthy rats could be maintained’ (Calhoun, 1952: 140). This was no mere literary device. By extrapolating the logic of the laboratory to a population, Calhoun was not only identifying the problem of the crowd, but addressing attempts to provide a solution through the modern apartment complex. This became more evident as his experiments increasingly shifted from modelling a ‘natural’ environment to an explicitly ‘garden culture’ once employed at the National Institute of Mental Health from 1954. Calhoun’s was combining elements of both Richter’s and Davis’s systems by privileging, to a greater degree, the relationship between the psychosocial and the design of physical space. It is in Calhoun’s experiments that the laboratory animal and the urban human, laboratory space and city space, become analogous.

Calhoun (1952: 140) argued that the population had stabilized at such a low level due to the expression of ‘genetically determined and culturally modified behavioristic potentialities, which were impossible under [isolated] caged conditions’. The rat had, like many social animals, become biologically disposed to living within a social group of approximately 12 adults – a dominant male controlling a home range in which there were enough material resources, a limit to unwanted social contact, and the emotional reward of living within a cohesive community. As his ‘Garden of Eden’ became a ‘rat city’, there was no longer the space for such requirements to be met. ³⁴ While dominant ‘boss’ rats were able to secure territories in the corners of the pen, crowding elsewhere prevented the emergence of stable hierarchies, ensuring that the lives of ‘plebeian families’ were marked by constant unwanted interaction and the failure to complete tasks, a breakdown in social norms and aggressive competition for space. ³⁵ At the NIMH, he pushed this mode of experimentation yet further, high population density among various strains of rats and mice, wild and domesticated, leading not only to violence, but to sexual deviance, cannibalism and withdrawal.

Davis had focused on the broad biological laws of population, and, with Christian, continued to detail the critical physiological mechanisms across a range of species (Christian et al., 1965). He paid little attention to social behaviour beyond positing an aggregate of competitive individuals. He also paid little attention to the details of his experimental architecture, merely quantifying the numbers of individuals per unit of space. Davis and his allies had turned to the laboratory in order to predictably generate crowding stress among their animals at a particular level of density. They then carried out careful and detailed endocrinological investigations. This would provide credibility for their argument that stress functioned as a mechanism that influenced the fluctuations in populations identified in field studies, and respond to criticism regarding the role of density-dependent factors in population regulation. ³⁶ Calhoun sympathized, writing Christian: ‘Perhaps further laboratory work is after all necessary before we are ready to take on the more difficult situation of open populations.’ ³⁷

Calhoun, however, was particularly comfortable in the laboratory – the more unnatural the better – as his audience had changed; he describes having ‘reset my course toward developing contacts with such fields as psychology, psychiatry, and sociology’. ³⁸ Here he would model the problems of the American city – the perceived relevance of his studies to human ecology having secured him a position at the NIMH in the first instance, with the aid of Alan Gregg of the Rockefeller Foundation (Calhoun, 1977: 49). While he may have shared much of Davis’s population perspective, his solution to the problems of urban living differed significantly. Modern apartment complexes, even the very ethos of sanitary modernism evident in the Baltimore Plan, had allowed, even encouraged, the massing of large numbers of people, with restricted resources, in restricted spaces. Indeed, Calhoun’s concern at the consequences of ‘rodent utopia’ was just as easily mapped onto Richter’s characterization of the laboratory as a ‘welfare state’.

Like Richter, Calhoun also wrote of allowing the animals to express their behaviour to the researcher. ³⁹ He meticulously followed the lives of a number of marked animals, combining individual charts and tables with the statistical methods of the population biologist. He also spoke of the need to understand the ‘whole organism in all the complexities’. ⁴⁰ Calhoun’s holism, however, extended beyond physiology and behaviour, to encompass ‘associations with others in the context of physical surroundings’. ⁴¹ Further, while Richter ignored issues of learning and plasticity, Calhoun sought to combine the perspectives of ethology and behaviourism. For Calhoun, behaviour was malleable, created and altered through the experience of social interaction and the design of physical environment. Richter’s rats may well have been genetically different, their limitations stemmed from the experience of living in an environment constructed according to flawed modernist design principles – isolated in identical individual cells, stacked together row upon row. ⁴² While Richter had thought himself an ethologist, he had ignored one of the rat’s most fundamental needs – the company of others. Calhoun (1973: 3) described being ‘squeamish’ and disturbed by the ‘boxes’ used to house animals in psychological study. Granted, scientists were able to compact a large number of physically healthy animals in a restricted space, but only at the cost of severely limiting behavioural repertoire. For Calhoun, these animals existed at a much lower psychological, social and evolutionary level as they were deprived of stimulus and not part of a communication network. The rats, like so many urban residents, were ‘housed in sterile jail cells’. ⁴³

For Calhoun, organizing a society to give each individual just enough room would result in social stagnation, which, in evolutionary terms, guaranteed decay – ‘utopia’ was ‘death’ (Calhoun, 1973: 22). Like Richter, Calhoun believed that animals required stress to survive and evolve; the experience of social interaction, however, was more than adequate. Throughout human history, crowding had spurred innovation, creativity, new social roles, and technological advance. This was no deterministic system of negative feedback; it was an open system that offered the potential of complete annihilation, but also of an increasingly complex and compassionate global community. The key was designing a physical environment in which an individual would be continuously challenged by stimuli, but not overwhelmed. By exerting more experimental control over his laboratory populations, he built smaller, more socially rewarding and advanced sub-communities within the larger population (cf. Ramsden, 2011). While Richter (1952: 283) had feared an oppressive Orwellian future, for Calhoun not all aspects of ‘Big Brother’ were bad. ⁴⁴ His experimental architecture had not only made visible the psychosocial forces that generated stress, it had also allowed him to manipulate those forces, as social and behavioural scientists noted (cf. Baum and Valins, 1977). It was by modelling not just an urban animal, but an urban space, that Calhoun enrolled wider interest in his laboratory as providing new possibilities for the control and improvement of urban humans.

Calhoun’s interest in the built environment extended to his vision of science – he designed research laboratories that would encourage communication and community-building among scientists. He painstakingly organized a vast array of extracts from a total of 162 authors to create a ‘reader’ of sorts, in mental health, population and the environment (Calhoun, 1983). ⁴⁵ He also proposed, and received no small amount of support for, a science- and technology-based version of the Peace Corps to the AAAS and NAS. ⁴⁶ Calhoun’s philosophy was steeped in Allee’s optimistic vision of cooperation among animals (Mitman, 1988), complemented by systems theory which emphasized the connectedness of things as a corrective to the atomizing effect of specialization. He even developed a particularly ambitious plan for a global ‘alerting system’. This was a communication network of scientists, planners and experts that would identify critical problems facing humanity, structured in accordance with the optimum group size – 12 – observed among rodent populations. ⁴⁷ Just as one should not isolate individuals within boxes, in either the experimental laboratory or the modern city, it was essential not to isolate scientists and intellectuals in separate cells of expertise. While he, like Richter, celebrated the creativity that he had gained from his own periods of intense struggle, stress and isolation, ⁴⁸ civilization would not advance through the travails of the individual, but only through the development of a truly integrated global community.

OPEN IN VIEWER

Figure 1.

Richter’s laboratory; the cages consist of a living space and an activity wheel. (The Alan Mason Chesney Medical Archives of the Johns Hopkins Medical Institutions)

OPEN IN VIEWER

Figure 2.

Calhoun sitting in a section of his ‘rat city’, Towson, Maryland. (Courtesy of the National Library of Medicine)

OPEN IN VIEWER

Figure 3.

An ‘urban’ universe for mice designed by Calhoun (on right), comprising of 256 ‘apartments’ set in ‘high-rise’ structures. (Image courtesy of National Library of Medicine)

Conclusion

For all the scientists involved in the rodent ecology project, working to control rat populations contributed a broader concern with the problems of stress in the modern built environment. Our scientists were, in Bauman’s sense, ‘gardeners’ – they constantly supervised and intervened to ensure that civilization was not ‘overwhelmed by wilderness’ (Bauman, 1987: 51). Yet all three scientists also identified limits to, and problems with, this intervention. They continuously describe being surprised by the rat, increasingly impressed by the need to enroll, rather than directly manipulate, its behaviour and physiology. Certainly, for Bauman, it is the distinguishing mark of modernity that a man-made order ‘is bound to remain an artificial imposition on the unruly natural state of things and humans’; indeed, it is its very vulnerability that demands ‘constant supervision and policing. … Escape from the wilderness, once embarked on, will never end’ (Bauman, 1992: xv).

In organizing his laboratory to store, breed and study the animal, Richter believed he had inadvertently created a garden culture which had severe consequences for the rodent body, just as the city had severe consequences for the genetic quality of modern humans. In the rats of Baltimore he had encountered the ‘wilderness’, encouraging him to reflect and romanticize about an alternative wild culture in which the strength, resourcefulness and creativity of the individual were essential to survival. Gellner’s garden culture analogy seems particularly pertinent here: ‘Agrarian man can be compared with a natural species which can survive in the natural environment. Industrial man can be compared with an artificially produced or bred species which … can only function effectively and survive in a new, specially blended and artificially sustained air or medium. Hence he lives in specially bounded and constructed units’ that need to be continuously ‘serviced’ (Gellner, 1983: 51). While Richter gifts ‘man’ immense power to dominate and domesticate nature, his ideal world is also suggestive of the gamekeeper, one which Bauman recognizes to be fundamentally nostalgic – a utopia based on the resurrection of a past in a future, not a future in the present. In science also, his vision is reminiscent of an idealized earlier time, as described by Bauman, in which the general intellectual had both independence and influence. Experimental designs were to be simple and intervention limited, allowing for the refinement of ideas rather than their substitution. He often boasted of his ability to understand and handle animals, allowing them the freedom to express their own innate behaviour, to act as their own controls, just as the scientist required the freedom to pursue his or her own research agenda.

For Davis, the boundary between wilderness and civilization was blurred, such had been humans’ impact on the environment, and so fundamental were the laws of population dynamics across species and spaces. For Davis and his collaborators, Baltimore’s rats were not the wild animals as idealized by Richter; they benefited from the provision of food and harbourage, and, as a consequence of population density, suffered the diseases of civilization. But neither were they specifically urban. The solution was to manipulate the interaction between innate needs, shared across species, and the built environment. This Davis described in terms of a gamekeeping model – manipulating the environment in which the rats acted, rather than attempting to directly control their numbers through poisoning. Yet this, of course, demanded not less intrusion into the lives of the urban population, but more surveillance and management. He lent his support to the modernist programme of urban renewal – replacing slums with clean, ordered and controlled apartment buildings. Such buildings not only reduced the rat population, but removed undesirable human inhabitants – the ‘weeds’ or ‘pests’ from the ‘garden’, Bauman noting modernity to be a ‘blatantly and self-consciously territorial world’ (Bauman, 2003: 12). Yet, for Davis, there was also a limit to what they could achieve as scientists. The removal of all rats was impossible, as they were adaptable and unpredictable, rats controlling, in a sense, their own population. There remains a certain fatalistic sensibility that pervades Davis’s ecological systems – that urban gang violence is the inevitable result of innate aggression (1962); that urban renewal ultimately depends on the vagaries of politics; that, in spite of the successes in public health, and in part because of them, civilization would continue to be marked by the stress, disease and violence that inevitably accompany population growth.

It is with Calhoun we have the realization of a gardening philosophy par excellence. The idea of the human as driven by its needs as an animal is now fused with a behaviourist’s sensibility – both the rat and the human were pliable, to be moulded and improved. Crucial to Calhoun’s system is the notion of space, which becomes more than an area in which the animal is housed and studied, and more than a physical environment to be ordered in accordance with physiological needs. Calhoun (1973) describes his pens as a ‘new sort of box’, one that allows for the study of the complex relations between numbers and space, and for the generation and manipulation of a range of social behaviours. The individual suffered from life among the crowds of a rat city, but also from the denial of communal living through solitary confinement in the isolated cage. The result was a heady combination particularly palatable to a generation concerned with the problems of the city. Consistent with the writings of many population scientists, Calhoun’s continued experiments identified the dangers of the crowd; consistent with many social and behavioural scientists, they suggested that there was no solution in a ‘utopian’ future of modern apartment complexes that segregated and isolated. The solution was to be found, just as it was in Calhoun’s later rat cities, by continuously striving to build better communities through the more effective design of physical spaces.