Pavlov’s laboratory was also, as one visitor put it, a “kingdom of dogs.” Canine inhabitants lived and worked there for years, and their personalities became an integral part of lab lore, the subject of jottings in the notebook compiled for each dog, a constant factor in the interpretation of experimental results, and the theme of one of the lab’s longest-lasting and most robust lines of investigation. Research on “nervous types”—Pavlov’s term for physiological constitution and personality—expanded constantly during the 1920s and 1930s. This research also encouraged and became inseparable from inquiries into the roles of heredity and environment, a eugenics project, and studies of mental illness.
When studying digestion, Pavlov had pronounced the dog “almost a participant in the experiments conducted upon it”; in CR research, there was no “almost” about it. Injunctions to objectivity notwithstanding, lab parlance routinely equated the dog’s labors and personality with those of its human collaborators. Dogs were not “experimented upon”—rather, they “worked.” Some worked well, others poorly. Some tasks put before the dog during its workday—for example, forming a CR to the beat of a metronome—were relatively easy. Others—such as differentiating between two speeds of that metronome—were more difficult. Still others—such as forming a delayed reflex to an electrical shock—were so extremely demanding that only a noteworthy few proved capable of them. Individual animals responded differently to the requirement that they sacrifice the freedom of life off the experimental stand for the restraint demanded during the workday, and some bridled at their working conditions—refusing, for example, to work with an unfamiliar coworker or in the isolated chambers of the Towers of Silence.
Like their human collaborators, dogs exhibited individual strengths and weaknesses and performed better at some tasks than others. The first coworker to work with a dog chose its name, and the dog’s personality often provided the inspiration: for example, Milord was imperious and Umnitsa (“clever one”) perspicacious. After a particularly demanding series of trials, a dog might be granted a rest, lounging in the kennel for an entire summer. Also like their human counterparts, dogs could be hurt or even broken by the burdens of work or life in general—by an overly taxing task, a fight in the kennel, or the loss of a sexual partner. Sometimes an experience on the stand or with another dog elicited an unexpected reaction that exposed a deep wound from an animal’s pre-lab life. Burdened beyond endurance, it might whine, refuse to eat or work, behave in an uncharacteristically timid or aggressive manner, or present symptoms of mental illness.
These were not viewed as mere behaviors, but as expressions of clearly defined constitutions and personalities. Just as Pavlov recognized characters from Gogol’s Dead Souls in the bird cage at the Petrograd zoo, so did he and his collaborators routinely describe their canine coworkers as weak or strong, lethargic or active, obtuse or intelligent, compliant or independent, passive or impressionable, aloof or sociable, modest or greedy, cowardly or heroic. Rait-Kovaleva, for example, described her Bes as plodding and unimaginative but a “good worker.” Undistracted by extraneous noises and movements, this proletarian animal formed CRs and differentiations slowly, but his hard-won knowledge proved “solid and lasting.” Her other dog, the “scholarly” Toy, was easily distracted, and, if not challenged with demanding work, even fell asleep on the stand (boredom). Yet, once engaged, Toy easily outpaced the workmanlike Bes.1
Some animals proved truly distinctive. One was so exceptional in ability and performance—a “genius”—that the chief himself approved the decision of an enchanted Maria Petrova to award it the moniker John (the anglicized version of Ivan). Pavlov himself identified another standout, Pingel’, as “a Napoleonic type” for his great energy and appetite and his crafty, single-minded pursuit of his goals, and regaled attendees of the Wednesday meetings with weekly tales of the unprecedented achievements of a “heroic” animal with “the nerves of a knight.”2
The kingdom of dogs, then, provided material aplenty—both on the stand and off—for Pavlov’s quest to understand the mysteries of the psyche. Any division between experiments and “life itself,” like that between “objective physiology” and common anthropomorphic perceptions, was extremely porous. To the extent such divisions existed, they constituted not unscalable walls erected by doctrine or objective scientific method, but rather relationships to be explored. How to explain the differing responses of Bes and Toy to CR experiments, and how to map these upon their strikingly different personalities? How to use Pingel’s salivary performance in various trials to explain his Napoleonic nature—and, by extension, that of Napoleon himself?
The concept of nervous types also provided a highly flexible variable for explaining puzzling experimental results. Two dogs responded differently to the same experiment? Clearly, they were of different nervous types. A dog seemed in some ways to belong to one type, but in other ways to another? Perhaps three types (or four, or even twenty-five) were insufficient to account for natural diversity, to explain the range of personalities by deterministic physiological laws. A dog behaved like a coward but registered as “strong” on the experimental stand? Perhaps inborn temperament differed from acquired constitution.
As the number of coworkers, dogs, and experimental trials grew, the resulting experimental data became increasingly discordant and their relationship to personality and behavior increasingly difficult to divine. An expanding typology of nervous types provided a plausible and convenient explanation. In this way, through the analysis of nervous types Pavlovian doctrine became both increasingly far-reaching—encompassing constitution, temperament, personality, the interplay of heredity and experience, and mental illness—and also less precise, less refutable, less pravil’nyi.
Pavlov himself understood and worried about this. Did it mean that his quest itself was hopeless, or simply that the path was long and twisting? He alternated between exhilaration and depression. A single satisfying experimental result invariably renewed his confidence that “we are indeed on the right road,” but the inexorable accretion of complexity and contradictions continually nurtured his “Beast of Doubt.”
* * *
Coworkers had always noticed differences in their dogs’ personalities and salivary responses to experiments, and it was always assumed that the same nervous qualities and dynamics underlay both. As research accelerated in the last decade before World War I, so too did such observations. Dogs varied in the quantity of salivation elicited by the same stimulus; the number of trials required to form a conditional stimulus (CS) and conditional inhibitor (CI); the speed, precision, and durability of differentiation; the rapidity with which CRs became extinct if not reinforced; the ability to form a delayed reflex; and the strength of the “orientation reflex.” Coworkers sometimes noted a correlation between these qualities and the animals’ behavior and affect.
During this first decade, Pavlov’s identification of excitation and inhibition as the two basic nervous processes framed the lab’s first typology. In his thesis of 1910, Petr Nikiforovskii offered a formulation that was widely employed by other coworkers into the early 1920s. He categorized dogs loosely among three types. First were those in which excitation predominated. These were “unusually active, nervous, sensitive” animals that often salivated continuously even in the absence of any stimulus and reacted sensitively to any change in their surroundings. During experiments, they “twist and turn, yelp, and show great restlessness and eagerness to free themselves from the cramped conditions of work in the stand.” In the second type of dog, inhibition predominated. Such animals were usually immobile in the stand, responded “only weakly to extraneous and insignificant changes in their environment,” and formed delayed reflexes unusually quickly. For Nikiforovskii, these two types represented a minority; most dogs, the “usual type,” were balanced.”3
This typology offered a set of loose working definitions that allowed experimenters to explain variant results. Coworkers sometimes described their dog according to its behavior and/or personality, sometimes according to its salivary responses during experiments, and sometimes attempted to link the two.4
One especially important difference among animals was their varying tendency to fall asleep during experiments, a frequent occurrence that constantly frustrated coworkers and ruined their experiments. In the early 1910s, Pavlov directed his coworkers to study this phenomenon, and the lab developed methods to keep animals awake by varying the exciters used during trials or by using electrical shock as a CS. Here, too, however, various dogs responded in differing ways.5 In a key thesis of 1913, Rozhanskii demonstrated to the chief’s satisfaction that sleep resulted from “internal inhibition,” which irradiated from its point of origin through the cortex of the large hemispheres and then to the lower-lying parts down to the spine.6 Sleep, then, was generalized inhibition. Experimental animals were especially prone to this, Pavlov explained in 1915, because when the same cortical cells were continually excited (by the constant use of a single stimulus) they passed into an inhibitory state in order to protect themselves from damaging exhaustion—and this inhibitory state spread throughout the cerebral cortex, leading to sleep.7
The liveliest dogs proved most likely to slumber on the stand. Reflecting upon this paradox in 1922, Pavlov speculated that when off the stand a lively dog received varying kinds of stimulation, but when on the stand it was unable to do so—and so fell asleep. Since, as Petrova pointed out in her thesis, this “tendency to sleep is not identical in all dogs,” and since each of the various phases of sleep influenced salivary responses, the experimenter needed to bear in mind this dimension of a dog’s individuality when interpreting experimental results.8
This, then, was the state of lab research on the individuality of dogs when Pavlov delivered his three public lectures during the dark days of spring 1918. In these speeches, he attributed Russia’s crisis to the chronic predominance of excitation in the imbalanced Russian mind and its resultant lack of realism.9
When his labs resumed full-scale operations after the civil war, Pavlov began directly to address the nature of nervous types. He assigned Evgenii Kreps to develop the first systematic physiological profile of an experimental animal, a middle-aged mongrel named Max. “Peaceful and unfrenetic,” Max seemed to belong to the middle type of “solid” dogs, but exhibited intriguing and distinctive social behavior: “Cowardly with people, he retreats from a shout or sharp movement, lies on his belly or freezes in an awkward stance—a passive-defensive reflex. With other dogs, on the other hand, he often conducts himself aggressively.” In experimental trials, Max formed CRs relatively quickly, but accomplished differentiation slowly and poorly—unable, for example, to distinguish between M76 and M144 or even, after more than 100 repetitions, between the tinkle of a bell and a loud crash. Kreps attributed this to an imbalance between the dog’s excitatory and inhibitory processes, but proved unable to map Max’s performance during experiments upon its behavior and personality.10
In mid-1922, Pavlov and Petrova launched their three-year study of two dogs, Postrel and Milord. Ensconced in their semiprivate experimental quarters on the second floor of the Towers of Silence, the couple laid the basis for Pavlovian research on nervous types and the related subject of experimental neurosis. This, in turn, generated a new line of investigation that joined lab research to the clinic and became Petrova’s great claim to fame: “the experimental pathology and therapeutics of higher nervous activity.”
They chose the two dogs for their sharply contrasting personalities. The older Milord was “solid, balanced, and peaceful,” “calm and not very mobile”; the younger Postrel “very lively and active.”11 Petrova and Pavlov first established that the dogs’ salivary patterns during experiments indeed mirrored their differing personalities. They established CRs in each animal for six stimuli (the metronome, an electrical buzzer, a whistle, the flash of an electrical lamp, the gurgling of water produced by a puff of air, and irritation by the needles of the kololka). Calm, solid, balanced Milord efficiently formed CRs and the more difficult delayed reflex to all six exciters—and clearly enjoyed the task of balancing excitation and inhibition, afterwards becoming “livelier in appearance” and eating with gusto. The lively Postrel formed the six basic CRs even more quickly than did Milord, but proved inferior at differentiation and delayed reflexes. In each case, the “confrontation of excitatory and inhibitory processes” involved in this task proved so difficult for the dog that he “fell into such an irritated state and such a fury that further work with it was impossible.”
The two dogs, then, were of different nervous type. Postrel’s performance in experiments, like his behavior and personality, reflected an imbalance toward excitation. He formed positive reflexes quickly but had difficulty with tasks requiring inhibition and, especially, those requiring a balance between excitation and inhibition—and such trials elicited anger and exhaustion. Milord’s nervous system, on the other hand, leaned toward inhibition and was in better balance, so he formed positive reflexes more slowly but excelled at delayed reflexes and differentiation. These same attributes were recognizable in his “calm, solid” behavior and personality. (As always, these trials actually produced highly varied results—and, as always, available interpretive resources were mobilized to contain them.)12
Having established that their dogs differed in nervous type, Pavlov and Petrova decided to test what happened when the challenge of balancing excitatory and inhibitory processes was taken “to the extreme, to the point of a break.”13 For the first time, researchers sought to create what would soon be termed an “experimental neurosis.” Petrova’s article on the results, “The Pathological Deviation of the Excitatory and Inhibitory Processes during a Difficult Confrontation of these Processes,” became a Pavlovian classic and the foundation of much further research.
Pavlov later openly attributed this turn to the influence of Sigmund Freud and, in particular, to Freud’s analysis of the landmark case of Anna O. Generally critical of Freudian theory, he nevertheless credited the founder of psychoanalysis with some important insights that, like those of physicians in general, required the undergirding of a truly scientific, physiological analysis. As he put it to Horsley Gantt: “We cannot ascribe all of [Freud’s] ideas to fantasy. There is much truth in what he says. He has had great success, and this is because it is based on physiology. He makes the mistake of considering himself a psychiatrist instead of a physiologist, and he uses psychological terminology. There is much reality in what he has to say about the collisions and inhibitions in the brain.”14
Reminiscing years later about his decision to “produce neuroses in dogs by means of collisions” (between excitatory and inhibitory impulses), Pavlov explicitly identified Freud as his inspiration. The stenographic account of his remarks renders them in the third person:
In one of his early works Freud described a case of neurosis in a woman who had for many years needed to care for her sick, fatally ill father whom she loved very much, and who had suffered terribly from the expectation of his inevitable death, attempting all the while to appear happy to him, hiding from him the seriousness of his illness. Through psychoanalysis Freud established that this lay at the basis of the neurosis that developed later. Viewing this as the difficult confrontation of the processes of inhibition and excitation, Ivan Petrovich immediately proposed using this same difficult confrontation of two opposing processes as the fundamental method for eliciting experimental neuroses in dogs.15
Freud had used this case in Studies on Hysteria (1895) to illustrate his view that “hysterics suffer mainly from reminiscences” and to promote the talking cure. His analysis of Anna O. featured the play of psychic forces that conflicted, combined, and inhibited one another, and he sought to explicate the dynamics of these processes while remaining agnostic about their ultimate nature, just as had Newton with gravity.16
Pavlov identified Freud’s conflicting psychical actors as his own fundamental nervous agents, excitation and inhibition. In Pavlov’s reading, then, Anna O.’s hysteria resulted from the conflict between the powerful excitatory impulse of her grief and the strong inhibitory impulse of her determination to hide that grief from her father. The physiological basis of these emotions was identical in humans and dogs, he reasoned, so he should be able to reproduce this same conflict in Postrel and Milord.
When did Pavlov read Freud’s works in general and Studies of Hysteria in particular? Nothing in his personal papers, correspondence, or published works answers this question. We do not even know whether he actually read Freud’s works or just a reviewer’s account of them. Perhaps he was exposed to Freud in the late nineteenth century, since he was actively interested in mental illness from at least that time. But it seems more likely that he read Freud (or about Freud) in the early 1920s, when the Austrian psychoanalyst first enjoyed a great vogue among the Russian intelligentsia, his works were translated and published in great number, and Communists debated the relationship of Marxism and Freudianism.17
The leading proponent of a synthesis of the two, Lev Trotsky, took the time in September 1923 (shortly after scolding Pavlov publicly for his anti-Bolshevik lectures) to write him privately with the suggestion that the reflex doctrine might provide the physiological substructure to Freudian thought and so “encompass Freud’s theory as a partial case.” Georgii Konradi later described Pavlov’s evolving response to Trotsky’s letter. Upon receiving it, he was angry: “Devil take it, that vile Yid Trotsky has sent me some letter.” On the second day: “Why is he crawling into what’s none of his business?” Third day: “Still, it is interesting that Trotsky has some interest in our work.” On the fourth day, he announced that he would answer Trotsky’s letter. That response, if he ever wrote it, has never been found.18
In any event, Pavlov did not need Trotsky’s advice. He was already employing Freud’s analysis of Anna O. for his own purposes. As is evident from Petrova’s article, the pair had by 1923 embraced a fundamental interpretive departure from earlier views that accords precisely with Pavlov’s later description of his debt to Freud. Petrova explains the theoretical break with early investigations in her introduction, in which she fundamentally reinterprets the much-praised earlier findings by Maria Erofeeva, who had been celebrated since 1913 for demonstrating that even a painful electrical shock could become a CS. That is, after being paired repeatedly with feeding, the shock eventually elicited not the expected defensive reaction, but rather salivation (that is, a “food reaction”).
Now, however, Petrova noted that these experiments had not, in fact, always gone so smoothly. At least two of Erofeeva’s dogs had ceased salivating in response to shock, which elicited only “a strong defensive reaction.” Only after the dogs had been rested for months were experimenters able to restore the dogs’ “food reaction” to that painful stimulus (and this result was always shaky and inconsistent). These variant results—like other important discrepancies in Erofeeva’s experimental results—had earlier been attributed to various uncontrolled variables and ignored in public reports. Pavlov had even claimed publicly that “in all animals this experiment succeeds easily.” Now, however, Petrova and Pavlov seized upon these failures as unrecognized cases of a break: Erofeeva’s two dogs, they now concluded, had been broken by the collision of excitatory and inhibitory impulses—that is, by the clash between the excitatory, defensive response to shock and the inhibition of this response due to the pairing of shock with food.19
While Pavlov and Petrova reinterpreted Erofeeva’s data, another veteran coworker, Nadezhda Shenger-Krestovnikova, was writing up earlier research that provided yet more evidence for the new theory. On the eve of World War I, while testing the ability of dogs to distinguish between shapes, she had noticed that, after successfully differentiating between a circle and a set of relatively flat ellipses, two dogs had reacted strangely when failing to achieve the more difficult differentiation between a circle and a near-circular ellipse. Confronted with this latter task, one animal, Vampire, which had formerly been “totally calm,” now became “strongly excited (yelped, spun in circles, tore off the rubber [experimental] apparatus, and barked when standing in the courtyard and when led to the chamber for experiments).” The dog thereafter produced exceptionally high salivary responses to stimuli.
Analyzing these trials after the war, Shenger-Krestovnikova (and Pavlov) now concluded that the attempt to distinguish the ellipse from the circle had caused “overstressing,” which had crippled the inhibitory process and, therefore, resulted in the dominance of excitation. This was evident both on the stand—in the disappearance of previously established differentiations—and off the stand, in the animal’s restlessness. Vampire had thus been reduced to a “truly neurasthenic state.” Petrova and Pavlov sharpened this interpretation in light of their new Freudian insight: as in Erofeeva’s experiments, they concluded, Shenger-Krestovnikova’s dogs had suffered a break precipitated by the clash of excitatory and inhibitory impulses.20
This new interpretation presaged hard times for Postrel and Milord. The experimenters would now attempt to break them by eliciting intense clashes between excitatory and inhibitory impulses in their nervous systems. Following Erofeeva’s lead, they used electrical shock as a CS. In Petrova’s telling (she provided only scanty data), Postrel initially responded only with a “defensive reaction”—refusing to take the food, which he spat forcefully from his mouth. The dog also dozed on the stand, forcing the experimenters to vary the exciters to keep the animal alert. After repeated trials during which he was force-fed while the shock was applied, Postrel finally responded with one drop of saliva, which the experimenters managed over time to increase to five drops. This they interpreted as evidence that the animal had formed a weak CR to the shock. (This interpretation followed from Pavlov’s lifelong assumption that all physiological reactions are strictly purposive, so any salivary response to electrical shock reflected an association between the shock and food.) Steadily increasing the severity and duration of the shock, and still force-feeding the dog, they finally managed to elicit a more substantial twelve drops. (Even the scattered data that Petrova offers in her article attests to the unevenness of this response.) Postrel’s other, previously established CRs remained intact, so the pair concluded that the dog was functioning normally and the first phase of their trials had succeeded—they had established a CR to electrical shock.21
Now it was Milord’s turn. With his weaker excitatory process, the dog’s initial defensive reaction was also “much weaker.” He “growled lightly” and kicked up the leg upon which the electrode was fastened, but, unlike Postrel, immediately ate the food offered while he was being shocked. On the second day, Milord already responded to the shock with two drops of saliva and then “almost ceased to exhibit any defensive reaction, just slightly raising his paw.” During these trials, the animal produced a satisfying seven drops of saliva during a thirty-second shock. His previously established CRs retained their “solid, constant character.” Milord, too, had successfully developed a CR to shock.22
Pavlov now departed on his trip to the West while Petrova pursued the second phase of their experiments: raising the strength of the shock sufficiently to break the animals. Both dogs were first granted a forty-day summer holiday. When they returned to work, she verified that their CRs remained intact and then began accompanying food with increasingly strong electrical shocks.
Postrel soon broke—and in a specific direction. The dog’s reflexes now “lost their regular character,” varying wildly. Significantly, the damage was clearly to his inhibitory process: CIs now elicited salivation, differentiations became less “absolute” or disappeared entirely, and the dog lost his ability to form delayed reflexes. The excitable Postrel, then, had broken “in the direction of excitation” and become pathologically overexcitable. His inhibitory process, which had always been relatively weak, was now shattered.23
Petrova then broke Milord. Since this peaceful dog had a much weaker defensive reaction to shock than Postrel, she rapidly ratcheted up the current. On the twelfth day, Milord responded with “almost no defensive reaction” and rewarded Petrova with seven drops of saliva. Strengthening the current, Petrova noted that “the defensive reaction returned and was even sometimes very strong,” but, unlike Postrel, the well-balanced Milord continued to take the proffered food almost immediately, which presumably, reflected the dog’s ability to inhibit his pain response to the shock. In subsequent trials, the defensive reaction disappeared, but so did the dog’s salivary response to shock. Petrova interpreted both of these reactions as evidence of the decisive predominance of inhibition, a hypothesis that she thought was confirmed by the gradual disappearance of a salivary response to all positive stimuli. Even after being rested for a month and a half (during which the dog gained weight on a sumptuous diet of fish fat), Milord’s positive CRs remained “minimal.” Milord, too, had broken—but in the direction of inhibition.24 Petrova could now welcome her collaborator home with some exciting news: they had succeeded in eliciting experimentally “two different neuroses corresponding to the differences in their nervous systems.”25
Having rendered their dogs neurotic, the experimenters now attempted to cure them. Drawing upon her clinical experience, Petrova first rested them and then treated them with bromide salts “in light of its indubitable action in the treatment of several nervous illnesses in people.”26 (Pavlov had himself been treated with bromides during his bouts with neurasthenia and hysteria.) Milord did not respond to either therapy and was retired from experimental practice. Postrel, on the other hand, responded well to the bromides. The dog’s ability to differentiate was restored, and CIs now elicited a satisfyingly perfect zero drops of saliva.
This cure proved short-lived, but Postrel went on to a remarkable lab career. In the 1930s, the chief would thrill to his achievements, regaling his coworkers with regular reports and informing them that this “heroic” animal had earlier been much underestimated, that he in fact possessed “the nerves of a knight.”27
* * *
On September 23, 1924, almost precisely one hundred years after the great flood immortalized in Pushkin’s epic poem The Bronze Horseman, the majestic Leningrad sky assumed a particularly dramatic appearance, reminding coworker Iurii Frolov of a torn blanket. Powerful winds “ripped the blanket into shreds, and heavy iron pieces torn from the roofs flew through the air like false leaves.” By early afternoon, the city’s canals were churning and the Neva River had risen more than five feet. Five blasts from the cannons at the Peter and Paul Fortress sounded the traditional warning of an impending flood; by 1:50 these echoed every thirty minutes, and soon every fifteen. At 3:00, the swelling waters overflowed the embankments and washed onto the islands and peninsula that comprised the city, continuing to rise until they reached some 12.5 feet in early evening.
Leningrad’s imperial center, from the Winter Palace to St. Isaac’s Cathedral, was now an island, and the Summer Garden bloomed under water. Across the Neva River to the west, Vasil’evskii Island, home to the Pavlovs and the Academy of Sciences, was inundated. The city’s Petrograd Side, site of the IEM, was located in the delta between the Neva and the Little Neva, and it too was awash. Nineteen bridges, hundreds of trams, and thousands of buildings were flooded. Long lines formed throughout the city as citizens waited in knee-deep water to buy provisions. Fires, explosions, and banditry punctuated the scene. About 600 Leningraders died before the waters receded. The city’s Communist boss Zinoviev hurried home from a sanitarium, and Kalinin and Molotov rushed from the Kremlin to survey the scene.28
Rita Rait-Kovaleva had just completed her day’s work in the IEM lab and was taking a tram home when she saw “the river begin to escape its banks, slowly and steadily washing over the bridge and flooding the tram rails.” Stranded on the Petrograd Side, she took refuge for the night at Maria Petrova’s apartment.
The four coworkers and assistants who still remained at the lab saw the flood waters pour into the courtyard and realized that the dogs, which had been returned to the kennel some 5,000 feet away, were in grave danger. The rescuers found the animals’ cages filling rapidly with water. Pressed upward toward the wire ceilings, the dogs strained to keep their noses above water. To quickly rescue some 100 dogs from the rising waters, the four men swam into the cages, grabbed the terrified animals by the head, forced them underwater, guided them on a swim to safety through the submerged cage door, dragged them out through the flooding corridor of the kennel, collected them in groups, and ferried them across the inundated courtyard to the safety of the distant lab building. “The water rushed in so rapidly that the second group of dogs had to swim against the wind and current. With the third group, the people, too, had to swim.” The rescuers noticed that “the animals at this time completely changed their usual behavior. They huddled close to people and to each other; many wailed loudly, and even the most aggressive among them did not provoke fights, but rather were obedient.” Even dogs that had been “praised for their stronger nervous organization” underwent this ordeal “with very great distress.” But all were saved.29
When Rait-Kovaleva arrived the next morning, she found the lab’s library flooded, mud everywhere, and the dogs huddled on the second floor. Clearly agitated, they remained there for a day and a half until their kennel had been cleaned and repaired. Experiments were suspended for another week, by which time electricity had been restored and lab apparatus repaired.30
Most of the dogs resumed their previous work routine, but at least two did not: Viktor Rikman’s Umnitsa and Alexander Speranskii’s Avgust, each previously identified as cowardly and submissive, had lost their established CRs and were behaving oddly off the stand as well. Intrigued, Pavlov temporarily left Petrova’s side to work closely with Speranskii on an explanation.
This research launched Speranskii’s spectacular career. The son of a bureaucrat from the gentry, he had studied medicine at Kazan University and treated the rural poor before joining the medical corps during World War I. With the outbreak of civil war, he became a physician in Kolchak’s army. When the Reds conquered Kazan, he joined Kolchak’s flight east to Krasnoiarsk. The Red tide reached this distant redoubt in late 1919, and Speranskii made his peace with the Bolsheviks, serving as chief physician at their Clinical Military Hospital and as head of the surgical clinic at the local university. After the civil war, he later explained, he underwent a personal crisis and, “full of disenchantment and dissatisfaction in medical science and in the form of my participation in it,” he traveled to Petrograd in 1923, hoping to learn from Pavlov about modern experimental physiology.31 The chief welcomed another experienced physician and aspiring scientist into his expanding enterprise.
The new recruit was charming, talented, and enigmatic. Rait-Kovaleva, who was very fond of him, noted that “his unremarkable and peaceful appearance concealed great personal ambition, inexhaustible energy, self-confidence, and clear investigative talent.” In flamboyantly politically incorrect fashion, he gallantly addressed women as “lady” and kissed their hands in greeting; he loved music, played the violin superbly, and performed on Saturdays with a quartet at his home. A prankster, Speranskii once persuaded Kovaleva to ask Horsley Gantt, the lab’s visitor from the American South, if any Negro blood flowed through his veins. Gantt fancied himself a progressive, but stormed off insulted—to Speranskii’s delight. When absorbed in his music, Rait-Kovaleva noticed, Speranskii was peaceful and gentle, “but at other times he would literally turn yellow with rage and in a quiet fury would curse in flowery, vulgar Siberian slang.”32 Shortly after his arrival, he endeared himself to the chief by arranging with longtime coworker Petr Kupalov an excursion that introduced Pavlov to the village of Koltushi, a few miles east of Leningrad. There the threesome spent a magical few days walking in the countryside, playing gorodki, and discussing the great potential of a scientific facility in that charming setting.33
It was Speranskii’s great fortune to be assigned the dog Avgust, whose traumatic response to the flood enabled Speranskii to collaborate closely with Pavlov in experiments on the pathology of the higher nervous system. Through this collaboration, Speranskii, who, like the chief, expressed hostility toward the Bolsheviks, became one of Pavlov’s favorites in the mid-1920s. A regular participant in games of gorodki and a frequent visitor to Pavlov’s home even after he left the chief’s lab in 1928 to head his own division of pathophysiology at the IEM, he was, before his fall from Pavlov’s grace in 1934, one of very few work associates to converse with the chief using the familiar pronoun ty. He also became a close associate and ally of Maria Petrova and, despite his avowed anti-Communism, of fellow Siberian (and Communist apparatchik) Lev Fedorov. For years, Speranskii’s lab bench was located next to Pavlov’s study, allowing him to participate in, or simply overhear, the chief’s discussions there.
Indeed, a persistent rumor among coworkers held that Speranskii was a stukach (informer). Pavlov later gave this rumor some credence, but by that time Speranskii was a scientific star in his own right, a member of the Leningrad Soviet, and a participant in the discussions with Stalin, Gorky, and Fedorov that culminated in the founding of the new All-Union IEM in Moscow (VIEM). He moved to Moscow in 1934 to head the VIEM’s Division of General Pathology.34
Before the flood, Speranskii’s Avgust was “a very lively, mobile, greedy dog, without any aggressiveness toward people and other dogs”—but his distinguishing trait was “submissiveness and cowardice.” If Speranskii shouted, clapped his hands, or moved suddenly, Avgust would wag his tail, squat on the floor, and urinate. That same timidity was evident in the dog’s reaction to even a minor change in working conditions. After an adjustment to the opening in his feedbag, Avgust refused to eat from it for a week, and when experiments were moved to a new room he refused food on the stand until restored to familiar surroundings. This idiosyncrasy aside, Avgust proved a good experimental animal, developing healthy CRs to six stimuli. As was expected according to the “law of strength,” the dog responded with the most copious salivation to the “strongest” stimulus, the buzzer. And as expected of a dog with a healthy inhibitory process, he performed differentiations successfully.35
When experiments resumed a week after the flood, however, Avgust failed to salivate in response to any of his established CSs, and exhibited a “clearly negative movement reaction” to the feedbag. This latter seemed especially strange, given his previous “greediness and inexhaustible appetite.” Over the next few days, Speranskii checked the dog’s health and instructed the attendants not to feed him off the stand. Yet the strange behavior persisted.36
Pavlov now joined Speranskii, and he noticed that the dog’s affect changed when alone. Peacefully occupying the stand when his master was present, Avgust became noticeably excited (panting and moving fitfully) upon his departure. Exposure to a CS only exacerbated this response. Pavlov now conducted experiments from outside the room while Speranskii remained with the dog. In Speranskii’s presence, Avgust approached the feedbag and ate from it normally, and his responses to most CSs now resembled those before the flood.
His response to the buzzer, however, showed that he had not recovered. The dog “suddenly hopped to his feet and began to fitfully move upon the stand and howl.” When the buzzer ceased, he “squatted on the floor in his usual pose when exhibiting a passive-defensive reaction.” Not only the buzzer, but, now, all CSs produced much lower salivary reactions than they had before the flood.37 The experimenters then conducted various trials in which they used Speranskii’s presence in the room to restore Avgust’s previous responses. Having succeeded, they weaned the dog off of this “social factor” by gradually replacing Speranskii with “components” of his presence (for example, by leaving his jacket in the room). By November 10, Avgust finally responded even to the buzzer with levels of salivation that approximated pre-flood levels, though a closer reading of the data revealed some continuing pathology.
The experimenters now hypothesized that Avgust’s peculiar reactions resulted from the trauma of the flood. This seemed to explain the appearance of odd behaviors, his response to Speranskii’s comforting presence, and his especially marked response to the buzzer, which resembled the alarm siren that had sounded with the rising flood waters. They prepared a decisive experiment that recreated the conditions of that day. An “artificial flood” was prepared by filling a container with twelve liters of water and feeding a rubber tube from it to pour water onto a noisy metal sheet and into the experimental chamber where Avgust was harnessed to the stand. The buzzer was sounded and the water released. Rait-Kovaleva later recalled the dog’s reaction: “He tossed about against the straps, whined, and strained against the stand! And after this he did not eat, gave no reflexes whatsoever—in a word, ‘he broke.’” Three minutes later, Speranskii began exposing Avgust to CSs. The animal responded not by salivating but rather with a “defensive reaction”—panting and twirling about in the stand.38
Over the next year every attempt to restore the dog’s CRs failed. In fall 1925, probably in order to round out this story for Pavlov’s upcoming address to the Parisian Society of Psychologists, Avgust was again exposed to the buzzer. After an initial salivary reaction, he sank into “various hypnotic phases intermediate between wakefulness and sleep.”39
Interpreting the results in consultation with Pavlov, Speranskii stressed the importance of nervous type and the relevance of his findings to traumatic neurosis in humans:
Translating all this into the language of clinical neuropathology, one could say that in our case we were dealing with so-called traumatic neurosis, or fear neurosis (Angstneurose), that is, an illness characterized by a sharp disturbance of the balance of excitation and inhibition.... The identity of the external manifestations of the illness and its causes permits us, on the one hand, to consider the state that developed in our dog analogous to traumatic neurosis in people, and, on the other hand, experimentally to affirm the connection between such illnesses of people and the preceding action of a strong destructive stimulation.40
Only a few of the dogs subjected to the flood manifested these symptoms, which testified to the importance of inborn constitution. It made good sense that Avgust—“a dog with a sharply expressed passive-defensive reflex, and characterized by exaggerated inhibitory processes”—had responded by “breaking in the direction” of chronic inhibition (as had the constitutionally inhibited Milord in Petrova’s earlier trials). The combination of constitution and experience had rendered him neurotic.41
Pavlov was now sufficiently confident to share his results with a Western audience. Addressing the Parisian Society of Psychologists in December 1925 on “The Inhibitory Type of the Nervous System of Dogs,” he used the experiments on Avgust to demonstrate the power of his CR methodology to illuminate psychological subjects and offered a classification of nervous types that linked his research to Western medicine’s most ancient tradition.42 The dogs in his lab, he explained, displayed a great range of behaviors and personalities, which had long made it difficult to “to completely reproduce our facts in [experiments upon] different animals.” By grouping these varied results, however, he had identified several distinctive types of nervous system.43 Some dogs formed positive CRs easily, but negative inhibitory reflexes only with great difficulty; others, just the reverse; and still others seemed to do each reasonably well. These different performances in experiments corresponded to constitutional differences in behavior and personality.
Pavlov then addressed dogs whose behavior revealed them to be cowardly: “They walk cautiously, with tail tucked in and legs half bent. If we make even a slight sharp movement or raise our voice a bit, they shrink away and crouch on the floor.” Summarizing Speranskii’s experiments on Avgust, he explained these characteristics as the result of the predominance of inhibition over excitation. The relative weakness of the latter process, he explained, was probably rooted in the dog’s cortical cells, which contained either an inadequate supply of excitatory material or low-quality material that was easily consumed. An excitatory stimulus, then, quickly exhausted such dogs’ excitatory capacity, eliciting an inhibitory impulse that protected the cells from damage.44
Avgust’s salivary responses during experiments closely mirrored his behavior and psychological character. When his CRs diminished, the dog also responded to food, not by approaching it to eat but rather with a “passive-defensive,” fearful response. Clearly, “at the foundation of, so to speak, normal timidity and cowardice, and especially pathological phobias, lies the simple predominance of the physiological process of inhibition as an expression of the weakness of the cortical cells.”45
Surveying the dogs in his labs, Pavlov claimed that they corresponded to the classical Hippocratic types. For the Hippocratic physician, each constitutional type (sanguinic, melancholic, phlegmatic, and choleric) resulted from a particular combination of humors (blood, black bile, phlegm, yellow bile) and had its own recognizable predispositions and personality. These were influenced also by environmental conditions, particularly climate. When the combination of constitution, environment, and way of life gave rise to humoral imbalances, this resulted in poor health, which was treated by the physician through bleeding, purging, and, especially, regimen. It was the task of the Hippocratic physician, then, to analyze an individual’s humoral constitution and way of life in order to prescribe a regimen for restoring and maintaining the patient’s humoral balance.
Hippocratic constitutionalism, with its emphasis on individual differences, had survived over the centuries, taking on new form with the rise of anatomical, physiological, chemical, and mechanistic doctrines. And it had survived the emergence of the universalizing and reductive sciences—physiology and bacteriology—that inspired advocates of “scientific medicine” in the late nineteenth and early twentieth centuries. Indeed, the invocation of individual nervous types by the determinist physiologist Pavlov paralleled Louis Pasteur’s famous pronouncement that “the microbe is nothing, the soil is everything” and Robert Koch’s reluctant concession that the simple presence of the tubercle bacillus or the cholera vibrio did not necessarily mean—indeed, in the majority of cases demonstrably did not mean—that the patient would suffer the disease itself. In each case, a simple reductive principle failed to explain the diverse phenomena observed on the experimental stand or in patients. In each case, the added variable of individual constitution proved necessary. Like bacteriology, Pavlov’s determinist physiology recast, but did not transcend, the ancient notion of constitution and the age-old problem of the relationship of “soil and seed.”46
By invoking Hippocrates in his speech to the Parisian psychologists, Pavlov was pursuing the same conceptual and rhetorical strategy as he had decades earlier when attempting to connect his digestive research to the clinic and win the support of medical practitioners. Then, too, he had praised age-old empirical medical wisdom (the drugs, foods, and advice tendered by physicians in the treatment of digestive ailments), which he claimed to justify and elaborate through experimental science. Then as now, he was also drawing actively upon medical tradition—in this case, as he searched for a schema to guide his classification of nervous types. His attempts to connect his experimental findings to the Hippocratic foursome would always be forced and awkward, much more effective for short talks or media interviews than for the actual interpretation of experimental results.
In Paris, he claimed that his findings fit that typology “especially” well for the two “extreme types”—the sanguinic and the melancholic. (This was an oblique admission that he had little to offer regarding the phlegmatic and choleric.) The many lively dogs in his lab that fell asleep on the experimental stand were sanguinics, who “need constantly changing stimulations, who seek these unceasingly and, finding them, [are] capable of displaying extraordinary energy.” In a relatively monotonous setting—such as an experimental stand—such dogs “fall into a state of drowsiness and sleep.” (The model dog here was Postrel.) The “inhibitory type” Avgust was a melancholic. “Is it not natural to consider and name him melancholic if at every step, at every moment, the surroundings elicit in him always the very same relentless passive-defensive reflex?” Between these two types were two variants of the “balanced type”—presumably, the phlegmatic and choleric. In each, the excitatory and inhibitory processes were of adequate strength and interacted in a “precise and timely” fashion. He offered neither examples nor elaboration.47
The identification and scientific explanation of nervous types thereafter became a standard feature of Pavlov’s iconic image. Within the lab, nervous types constituted a central line of investigation and a flexible variable in the interpretation of experimental results. The Hippocratic typology, however, proved unable to encompass the steady accretion of puzzling discrepancies. Pavlov’s quest, and the methodology by which he pursued it, required from a nervous typology the illumination of basic patterns to systematize and explain at least three major orders of phenomena: the varied responses of different dogs to the same experiment, the responses of a single dog to various experiments that presumably tested different nervous qualities, and the presumably direct relationship between dogs’ performance during CR experiments and their observed behaviors and personality.
Four types, it soon became clear, would hardly suffice. The long journey to the horizon continued.