In the summer of 1923, Pavlov embarked on a four-month journey to the West. Invited to the French celebration of the hundredth jubilee of Pasteur’s birth in May and to the Eleventh International Congress of Physiologists in Edinburgh in August, he solicited an invitation to spend the intervening months in the United States. This trip provided his first prolonged contact with his Western colleagues since the war. It offered a respite from oppressive Russian realities and an opportunity to meet with foreign scientists, former students, and other Russian émigré scientists—and, especially, to proselytize CRs abroad, particularly among U.S. behaviorists, whom he had identified as his most likely allies in psychology.1
Pavlov’s Western colleagues had long hungered for more information on his research. As it turned out, however, his accounts of CR methodology, the laws of cerebral processes, and the nature of inhibition and sleep would be overshadowed by his enthusiastic description of fresh experiments on another controversial subject.
Pavlov had always believed in the inheritance of acquired characteristics. Like his mechanistic view of the organism, this belief was part of his longstanding scientific common sense. Commonly associated with Jean-Baptiste de Lamarck’s theory of species transformation in the late eighteenth and early nineteenth centuries, the inheritance of acquired characteristics also played an important role in the thinking of two evolutionists whom Pavlov much admired, Herbert Spencer and Charles Darwin. Although Darwin attributed evolution chiefly to natural selection, he frequently invoked the inheritance of acquired characteristics in his Origin of Species (1859)—and even more so in later editions of that work, when he was compelled to “speed up” the evolutionary process in response to Lord Kelvin’s authoritative (and erroneous) estimate of the age of the earth. Russian evolutionists of Pavlov’s generation followed Lamarck’s and Darwin’s lead almost without exception.2
Single-mindedly immersed in physiology, Pavlov paid little attention to the rapid development of genetics after the rediscovery in 1900 of Mendel’s earlier experiments on pea plants. By the 1920s, this prospering science was pursued with particular vigor and success by both Americans and Russians. Such leading practitioners as T. H. Morgan and Nikolai Kol’tsov insisted that hereditary material was largely isolated from somatic events and was certainly not altered in a directional manner by an individual’s life activities. For them, when a giraffe stretched its neck to reach the leaves on distant branches, or when a blacksmith strengthened his arm through constant exercise, this left no hereditary imprint upon the next generation in the form of a longer neck or a stronger arm. Many others, however, continued to defend this traditional view, including Austrian biologist Paul Kammerer, whose experimental results were publicized in Russia in the early to mid-1920s amid intensifying debates there about the relationship of Marxism to Lamarckism and Darwinism.3
Among the Russian geneticists who vigorously criticized belief in the inheritance of acquired characteristics was Nikolai Kol’tsov, with whom Pavlov was on friendly terms. When Pavlov rebuffed Kol’tsov’s attempt in 1916 to include genetics within the purview of the Sechenov Society of Physiologists, the geneticist noted perspicaciously that the elderly physiologist, whom he regarded with affection and respect, was uninterested in genetics and other newly emerging areas that seemed to him “foreign, borderland spheres of biology.” Beginning in the early 1920s, Kol’tsov and other geneticists sent Pavlov copies of the Russian translation of Mendel’s work and other landmarks in genetics—but these were consigned, their pages often uncut, to a distant corner of his library. The development of genetics, then, had not, by 1923, changed or even complicated Pavlov’s longstanding belief in the inheritance of acquired characteristics.4
That belief was evident in his speeches on “The Reflex of Purpose” (1917) and “The Russian Mind” (1918), and also in scattered asides to scientific audiences. For example, he commented to the International Congress of Physiologists in 1913 that it seemed likely that “several of the newly formed conditional reflexes [in one generation] are later transformed hereditarily into unconditional reflexes [in the next].”5
In a series of experiments from 1921 to 1923, Pavlov’s coworker Nikolai Studentsov seemed to confirm this. Studentsov investigated the number of repetitions required by successive generations of mice to develop a CR to the sound of an electrical buzzer. (He could not use dogs for these experiments because they produced new generations too slowly.) Repeatedly accompanying the sound of the buzzer with the opening of a feed bag, Studentsov compared the number of repetitions required by each generation to respond to the buzzer by approaching the food. For both coworker and chief, the results demonstrated the heritability of learning: the first generation required 298 repetitions, the second generation 114, the third 29, the fourth 11, and the fifth only 6.6
Enthusiastic about these results, Pavlov looked forward confidently to those with future generations, which, surely, would be born with the conditional reflex acquired by their progenitors. The CR, in other words, seemed well on its way to becoming an inborn UR. Studentsov was beginning his experiments on the sixth generation of mice as Pavlov prepared to leave Petrograd for Europe and the United States, now armed with yet another proof for his Western colleagues of the fruitfulness of his CR methodology.7
Kol’tsov heard of these experiments and visited Pavlov shortly before his departure—as the geneticist recalled, “especially to dissuade him of the possibility of such inheritance.” Pressed by Kol’tsov, Pavlov admitted that Studentsov had not compared the learning curve of his successive generations of mice with that of another set whose parents had not acquired this CR. In other words, there was no control group. (This was not unusual for Pavlov, who emphasized intensive trials with individual, model dogs.) Kol’tsov suggested that “the learning had been accomplished, not by the mice, but by the experimenter, who had [previously] no experience in the training of mice.” Studentsov had simply become a better mouse trainer over time. “I. P. listened attentively as if in agreement, but said that this was not his area of expertise and that he did not have his own definite opinion. I parted from him reassured that the work would be checked with what I knew to be the inevitable and certain result.”8 Yet Pavlov’s reluctance to engage Kol’tsov did not, as it turned out, signal acquiescence.
Meanwhile, Pavlov had begun the process of securing permission and travel funds from the Soviet bureaucracy. Fully expecting that the American colleagues who had repeatedly invited him in previous years would be willing to host him, he petitioned in late March for a four-month trip to England and the United States. “It is extraordinarily important for me to spend some time in America in order to speak with specialists working in the sphere to which I have devoted the last twenty years of my work, to see the circumstances of their activity, and to be present after a long absence at the International Physiological Congress in England.” Since he did not speak English, he required also the presence of his son, Vladimir, as translator. Should this trip not materialize, he warned, it would be a “great scientific loss.” As for the great costs involved, he reminded the authorities that “the October Revolution deprived me of the Nobel funds which I earlier used for my overseas scientific trips.” He apparently inquired informally about permission for Serafima to join him and Vladimir, but was told that only two members of the family could go.9
Mikhail Kristi, a Communist administrator on the commission established to facilitate Pavlov’s work, shepherded his request through the bureaucracy. In early May, Pavlov received his passport and permission to travel for six months to England, France, Germany, and the United States, but a good part of the promised funds was still missing. With the Pasteur celebration fast approaching, Kristi promised Pavlov that these would be waiting for him at the Parisian branch of Arkos, the Soviet trading agency.10 So, in late May, Pavlov and his son departed for Helsinki, traveling from there by ship to Stettin (now Szczecin, Poland) and then by train through Berlin to Strasbourg, where they joined the other celebrants of Pasteur’s jubilee.
He was no doubt a bit nervous that he had still not heard from the Americans. Pavlov counted on Walter Cannon at Harvard, with whom he had conducted an increasingly warm correspondence since 1912, to arrange his visit to the United States.11 In April 1923, he had used the good offices of another American contact to solicit Cannon’s help. W. Horsley Gantt, a physician with the American Relief Administration (ARA) in Petrograd, had first appeared at Pavlov’s lab at the IEM in October 1922. Fascinated by the research, he would become a formal coworker there from 1925 to 1929 and then the most important proponent of Pavlovism in the United States, founding a Pavlovian laboratory at Johns Hopkins and translating an expanded version of Pavlov’s 1923 collection of speeches and articles into English.
Gantt and Cannon had been collaborating on Russian relief, so, at Pavlov’s behest, Gantt used the offices of the ARA to send Cannon both a letter from Pavlov and another from himself explaining that Pavlov was planning to attend a conference in “Glasgow, England” [sic] and “has a desire to visit America from there.” Did Cannon “think that a trip from him would be well received, and could be financed in America at this time?”12 Cannon received the letters on May 8, and replied to Pavlov the next day that “You have a multitude of friends and admirers in the United States who would be most glad to welcome you.” He suggested that Pavlov use the remainder of the money deposited for him by his foreign friends in Helsinki during the hungry years to help finance his trip, and promised to arrange a series of lectures in New York, Baltimore, Washington, Boston, and elsewhere to cover further expenses. The only problem was the proposed timing of the visit. U.S. scientists would be on summer vacation and their labs empty, so he advised Pavlov to postpone his trip until the fall.13 Cannon’s response, however, arrived in Petrograd only on May 31, by which time, as Gantt informed him, the physiologist had already departed. “Very enthusiastic about going to America,” he was looking forward to talking with his colleagues there about recent research on several subjects, including experiments “showing that acquired characteristics can be inherited.” Cannon should expect him in mid-June.14
Meanwhile, Pavlov was enjoying the Pasteur jubilee in Strasbourg, which, he observed to Serafima, seemed mostly a celebration of the recent return of the city and the surrounding Alsace-Lorraine region to France by the Versailles Treaty. The masses on the streets attested to French national pride, and Pasteur himself was honored with a “grandiose banquet (with excellent food)” and a speech by Prime Minister Poincaré at the dedication of the local Pasteur Museum.15
Even before 1917, Paris and its Pasteur Institute had become a mecca for émigré Russian scientists. Now it teemed with such friends and former colleagues as Sergei Metal’nikov, Sergei Vinogradskii, and Alexander Vladimirov. Pavlov shared with both Soviet Russians and “Parisian Russians” the trip from Strasbourg to Paris on a special train provided by the French government, and he spent the next days in Paris enjoying the company of his ex-countrymen, who wined and dined him. “They are for some reason very glad to meet me,” he wrote to Serafima, “and somewhat overestimate my distinctiveness, which becomes truly awkward.”16 In its assessments of Pavlov’s political profile over the years, Soviet organs would always note darkly that he maintained contact with émigrés, but the physiologist considered it beneath his dignity to care. Conversely, he always considered it unpatriotic to publicly criticize the Soviet government when abroad, and indignantly refused to do so.
He remained in Paris for about ten days, longer than he had planned, waiting for a U.S. visa and the balance of his travel funds from Soviet Russia. A second letter from Cannon caught up with him there, asking him to defer his trip but promising a warm welcome in any case. “We shall do our best nevertheless to make your visit here a pleasant one,” Cannon promised, adding that he was contacting Harvard psychologist Robert Yerkes about demonstrating for Pavlov his experiments on primates. The Rockefeller Institute for Medical Research had extended to Pavlov a formal invitation to visit New York to acquaint himself with the work of physiologists and psychologists in the United States.17
In the early evening of June 13, the Pavlovs boarded the great steamship Majestic. Just as the Versailles Treaty had transferred Strasbourg from Germany to France, so had it awarded the Majestic, formerly the Bismarck, to the British as part of war reparations. Passed along by the British government to the White Star Line, it was the world’s largest passenger ship, so, Pavlov assured Serafima, “everybody reassures us about pitching.” It steamed across the Atlantic with its more than 2,000 passengers at about twenty-three knots, arriving in New York City in just over five days. The Pavlovs traveled second class in “marvelous” conditions: “One could wish for no better cleanliness and facilities. The food is wonderful; the only problem is that one can overeat. Volia said with justice that life on our steamship is life in an excellent sanatorium.” All was smooth sailing. “I eat, sleep, read a great deal, and think about all sorts of things—mainly about home, about all of you, and about you.” He notified Cannon by cable of their impending arrival.18
The bad timing of Pavlov’s trip and his tardiness notifying Cannon ensured that, despite the latter’s best efforts, few people knew in advance of his visit.19 Yet Pavlov’s American colleagues managed—even after an unforeseeable calamity—to arrange a stay that reinforced their visitor’s warm feelings for the United States and its scientific community. Upon arrival in New York City on June 19, the Pavlovs were greeted by representatives of the Rockefeller Institute, who escorted them to the Hotel York at Seventh Avenue and 36th Street. On the next day they visited the Rockefeller Institute, where they were hosted by Pavlov’s devoted former student at the Military-Medical Academy, Phoebus Levene, who now directed the biochemistry section of the Rockefeller Institute and was well known for his studies of ribonucleic acid (for which Pavlov had provided samples of pure digestive juices).
The facilities at the Rockefeller Institute were most impressive. Pavlov informed Petrova in a letter composed at day’s end: “The building is marvelous and located on the bank of a river. All the laboratories are enormous and equipped with every scientific means. Especially luxurious is the clinic, which is next to the labs related to it: chemical, bacteriological, and others. In general, enormous work is being conducted, a mass of new facts.... I looked at all this and was envious: we would do no less if we had such means.”20
The next day’s scheduled trip to Yale ended before it began in trauma for the Pavlovs and embarrassment for their hosts. Early in the morning of Saturday, June 21, the pair boarded a train for New Haven from New York’s Grand Central Station. As Vladimir placed their luggage on the rack above the seat, two thieves seized Pavlov and rifled the inside pocket of his coat, making off with his documents and all his money, about $2,000. Vladimir had enough cash to hire a taxi to Levene’s home, but when the Pavlovs arrived, they discovered that the bag containing their dress clothes had fallen off the cab’s roof. It, too, was lost.
“The trip to New Haven was immediately abandoned,” an upset Levene informed Cannon, “and the elder Pavlov had decided to borrow enough money to return home. He was terribly depressed.” Levene contacted Simon Flexner, director of the Rockefeller Institute, who offered $500 and urged Levene to assure Pavlov that American physiologists would raise additional funds for him to continue his trip. Pavlov refused, however, to accept any charity and “expressed the wish to return at once to Russia where he was safe.” Levene finally convinced him to at least visit Cannon in Boston, hoping that Cannon would persuade him to stay and buying time for the Americans to find a means of financing Pavlov’s trip that would prove acceptable to their distressed and prideful guest.21
Cannon met the Pavlovs at Boston’s train station and escorted them to his home in Cambridge and then to Harvard Medical School. He convinced Pavlov to accept the Rockefeller Institute’s offer to send him as “their agent” throughout the United States and to Europe. In that capacity, Pavlov would speak about his work to various audiences. Cannon informed Levene on June 25 that “When he got into the laboratory here and began to meet the workers I think that his spirit largely changed and he forgot some of his depression.” That evening at dinner in the Tavern Club, Pavlov expressed the opinion that Communism would fail because of the “very profound instinct of collection and possession in human nature.”
Cannon also took Pavlov to witness an operation by the eminent neurosurgeon Harvey Cushing and phoned Frank Lillie to schedule talks at the Marine Biological Laboratory at Woods Hole, Massachusetts, and the University of Chicago. By this time, the Rockefeller Institute had stepped in to rescue the situation, inviting Pavlov to visit American laboratories and to represent the Institute at the upcoming physiological congress at Edinburgh “to promote science in America and to assure success of the congress.”22
The impression made by Pavlov upon Harvard psychologist Robert Yerkes testifies to the traveler’s rapid recovery from the mugging at Grand Central Station: the photograph of Pavlov that had long hung over Yerkes’s desk did not prepare him for the Russian’s “remarkable energy, enthusiasm, and liveliness.” His presence was “exciting and bracing, like a breath of fresh air,” and he spoke engagingly about his investigations, plans, and expectations for the future, convincing his listeners of the “enormous importance of the Pavlovian conditional reflexes method.”23
In Pavlov’s letter of July 1 to Serafima, the robbery was already receding in importance beside the graciousness of his hosts and the charms of his surroundings: “We are alive and healthy and continue our trip in America, although there occurred with us a great unpleasantness. When we were about to leave New York for New Haven, money was taken from us—that is, from me. We had to postpone the trip, but a special Rockefeller Institute [fund] reimbursed us for everything.... The reception has been most friendly. Cambridge, especially, is a charming town, like one big dacha region.”
The next stop was Woods Hole, where the Pavlovs lived “superbly” with physiologist Jacques Loeb and his family, “the most amiable of people.” Woods Hole itself elicited more superlatives, and Pavlov expressed satisfaction with his presentation there: “The natural setting is wonderful, like Sillamiagi but even better. It is like summer at a dacha: here there are gathered for work around the sea many American biologists with whom Loeb acquainted me. The biologists asked me to inform them about our work, which I did on the third day. The audience was large, about one hundred people. Volia and I did the report together. I spoke short phrases in Russian and Volia translated into English. Judging by everything, the audience was interested and satisfied; there was much applause. After the report there were a few conversations.”24
No record exists of that talk, but it seems probable that he spoke unreservedly there (as he did at other venues) about Studentsov’s experiments on the inheritance of acquired characteristics. Kol’tsov later recalled—apparently from a discussion with Pavlov—that the audience included T. H. Morgan.25 Perhaps, then, the “few conversations” afterward included one with this most skeptical geneticist. If so, Morgan failed, as had Kol’tsov before him, to dampen Pavlov’s enthusiasm.
The Pavlovs sailed from Woods Hole back to New York, where they stayed at the Chemists’ Club and visited the Rockefeller Institute with Levene before setting off by train for Washington, D.C. Vladimir wanted to see the capital and rendezvous with some acquaintances from his days at the Thomson and Rutherford labs. He dashed about the city while his father, never much for sightseeing, remained in the hotel. At one physics institute, Vladimir met a Russian émigré with an automobile and lured his father out for a three-hour tour of that “very pretty city with a mass of greenery.”26
They then boarded a sleeping car for Chicago, where they were greeted by Alexander Maksimov, Pavlov’s former colleague at the Military-Medical Academy, who squired them around the city for several days. Pavlov spoke at the University of Chicago, which he found “marvelous, luxurious, all green,” and then traveled four hours to the sanatorium at Battle Creek, Michigan. Its director, John Kellogg, was a longtime devotee of Pavlov’s digestive work who had corresponded with him and visited his lab in Petersburg. There he was also reunited with his former student Vladimir Boldyrev, whom Kellogg had hired to conduct research in a specially built Pavlovian lab. Delighted to find his émigré friends so “well established,” he relaxed for one week amid the “extraordinary quiet and peace” of the sanatorium grounds.27
Here, after an honorary banquet on July 7, he delivered the third talk of his U.S. tour, speaking animatedly to a rapt audience of physicians. Probably much the same as his remarks at Woods Hole and the University of Chicago, his presentation was this time translated by Boldyrev and published four months later on the front page of Science. Succinctly reviewing the fundamentals of CR methodology, he moved on to the role of inhibition in differentiation, hypnosis, and sleep before closing with the exciting news that Studentsov’s experiments had demonstrated the inheritance of conditional reflexes. Reviewing the diminishing number of repetitions that had been necessary for each succeeding generation of mice to develop a UR to the buzzer, he concluded: “The sixth generation will be tested after my return. I think it very probable that after some time a new generation of mice will run to the feeding place on hearing the [buzzer] with no previous lesson.”28
From Battle Creek the Pavlovs traveled by train to Niagara Falls, where they spent one day admiring that “grandiose phenomenon of nature” before returning to New York and boarding the Majestic on July 14 for the return voyage.29
They had been unable, however, to obtain a British visa. In its only story on Pavlov’s trip, under the headline “Russian Scientist Barred By Britain,” the New York Times reported: “When Dr. Pavlov attempted to get the British visa to his passport he was told that it could not be done. He was accompanied by Dr. Levene, who explained that Dr. Pavlov was not a Bolshevist, that in fact he was anti-Bolshevist, but the passport bureau of the British Consulate maintained that they could not visa any Soviet passport without express instructions.”30 (The Times was clearly pleased to be able to headline this British embarrassment rather than Pavlov’s mugging at Grand Central Station, which it duly reported in the same article.)
The situation was rectified during the Atlantic crossing. American physiologists en route via the Majestic to the physiology congress in Edinburgh read the article in the Times and cabled their protest to the British authorities. Even before the ship docked in Cherbourg, the Pavlovs were informed that they had been granted a visa. Pavlov had by this time been convinced to deliver a talk in Edinburgh. To avoid their usual difficult and time-consuming joint performance, he and Vladimir collaborated during the voyage on an English translation of the same talk that Pavlov had delivered several times in the United States. He was touched by the concern of his American colleagues (“Very kind people!”), but confessed to his wife that “I am now rather tired of the trip and dream of being home.”31 Writing to Petrova that same day, he was thinking fondly of his lab. Reminiscing about the Rockefeller Institute, he again praised its “enormous means” and the interesting research being pursued there, but now added that “this luxurious laboratory also has a deficiency compared to ours: the small number of service personnel. Almost everything must be done themselves by the professors and their assistants.”32
The timing and last-minute nature of Pavlov’s trip to the United States had minimized his contact with American scientists and ensured that press coverage would be negligible. Yet articles in the New York Times and Time magazine shortly after his departure reflected a general interest in his persona and research. Each touched upon two standard features of what would become, by decade’s end, Pavlov’s iconic status. First, his energy and impressive appearance: “Pavlov is 75 years old, tall, white-haired, majestic, active,” reported Time; “a tall, distinguished looking man, straight despite his 75 years,” according to the New York Times. Second, his successful defiance of the Communist state. In an article laced with minor inaccuracies, Time reported also that “Despite his opposing beliefs, the Soviet government has protected him, supported his work, published his collected papers.” The Times, too, highlighted the fact that “Despite his anti-Soviet beliefs, the Soviet Government has protected him and aided him in maintaining his laboratories because of his scientific research.”
Time’s reporter devoted two paragraphs to Pavlov’s scientific work—to his “classic” studies of digestion, his “brilliant” use of the isolated stomach, and his current research, which it linked to bells and behaviorism: “By a simple surgical operation, Pavloff brought the duct of a dog’s salivary gland to the surface of the cheek and measured the flow under stimulus of food. At regular feeding times a bell was rung, and after several repetitions it was found that the sound of the bell alone, without food, stimulated the saliva. This process, known as a ‘conditioned reflex,’ has been repeated in scores of forms by physiologists and psychologists on both animal and human subjects. It forms the basis of much of modern ‘behavioristic’ psychology, and suggests how reflexes and instincts can be re-educated into new habits of conduct.”
In what would become the standard American view of Pavlov’s research, then, Time portrayed his great achievement as the establishment of the fact of this “conditioned reflex”—of the simple association of “bell” and salivation. This early moment in Pavlov’s research—which was for him, as we have seen, mainly a point of departure for his science of the psyche—was, as the article makes clear, the essential one from the perspective of behaviorist psychology, which framed Pavlov’s reception in the United States. Pavlov’s use of the methodology of CRs to develop a map of higher nervous processes in order to eventually explain the mechanism and mysteries of the psyche went unmentioned.33
The physiology congress in Edinburgh proved “very big and interesting.” Here Pavlov met with surgeon W. H. Thompson, the translator of Lectures on the Work of the Main Digestive Glands; physiologist Edward Sharpey-Schafer; and his friend and former coworker Boris Babkin. Neither Kol’tsov’s warnings nor any criticisms from his American colleagues had tempered his enthusiasm for Studentsov’s experiments, which he reported in almost precisely the same language as he had in Battle Creek, even including the confident prediction that “one of the next generations of our mice will show the food reaction on hearing the sound of the electric bell for the first time.”34 Everything was wonderful, but he was weary and homesick. Vladimir, however, insisted that they spend some time in England.35
So, in late July, they traveled to London and Cambridge—visiting Vera’s former English tutor, dining with Babkin and Anrep, and breakfasting with Vladimir’s physics colleagues in Cambridge. The Lancet reported on Pavlov’s visit to Middlesex Hospital in early August, describing him as “a striking example of the boundless activity and imaginative force which is the gift of the greatest scientists.” Taking pride in his praise of the hospital’s modern combination of teaching, research, and clinical practice, the reporter also used the visit to highlight a complaint of English researchers: Pavlov, he reported, was “disappointed to find here, as in other institutions in England, that research is seriously hampered by the severity of the restrictions on Vivisection.”36 In London, the visitor was fitted with a special shoe for the leg that had shortened after his fall in 1916.
“I very much long to be home,” he wrote to Serafima. “I am tired of this life among foreigners, and without the language.” Happily, they would be returning soon—by steamship from Hull to Helsinki and home by mid-August.37 A few days later, however, he informed her from London that their plans had changed, since “only very small ships” sailed from Hull and they did not want to risk capsizing during the current windy season. So they would return as they came: from Stettin to Helsinki “in a large steamship.”38
He and Vladimir then disappeared for a month. He wrote no more letters home and left no written record of his whereabouts. Soviet intelligence services were perturbed and perplexed. In response to an inquiry from the central organs, a certain Grinberg in Berlin reported on September 3 that “Pavlov’s location is not now known.” Soviet agents in London and Paris were also on the case, but Grinberg had only “private information” that “he is located somewhere in the provinces.”39
A plausible account of Pavlov’s whereabouts was provided many years later by Gedde Vyrzhikovskaia, who claimed that Pavlov spent some time at George Gurdjieff’s commune and Institute for the Harmonious Development of Man at Fontainebleau, outside Paris. Gurdjieff and Pavlov differed profoundly in their worldviews, and Pavlov hardly shared the Georgian émigré’s interest in reconciling Eastern wisdom with modern science. But the two shared a fundamental interest in hypnotism, the mind-body question, and the harmonious development of human beings, and Pavlov would not have been a rare visitor to the commune from the world of modern psychology.40 He finally returned to Petrograd in mid-September.
His endorsement of the inheritance of acquired characteristics had caused quite a stir—and elicited a coordinated negative response from geneticists. T. H. Morgan assured William Bateson in February 1924 that articles criticizing Pavlov’s conclusions were in the pipeline. He had directed two of his associates to publish their data disproving any inherited effect of training and alcohol use in lab mice and rats. “Neither of them will refer to either Pavlow or Kammerer. This data, however, will serve, I think, as an answer to the question that is continuously being asked: is there anything that disproves Pavlow’s statements? As a matter of fact, Pavlow has not given anything more than his conclusions, which, obviously, are exaggerations. If there is any such change as he finds it must be due, I think, in large parts to improvements in his technique, or in the domestication of what he calls his ‘wild white mice.’”41 Those two articles appeared in Science one month later. Their common conclusion was that “The later generations have not been aided in learning the maze by the training of their ancestors.”42
Morgan scolded Pavlov by name in his own article of July 1924, “Are Acquired Characters Inherited?” Reviewing experimental evidence that demonstrated the “isolation of the germ plasm,” he then devoted a few pages each to Kammerer and Pavlov. “There was some consternation last summer,” he wrote, “when the great Russian physiologist, Pawlow, reported the results of experiments that go far beyond what most Lamarckians have dared hope. Pawlow’s conclusions—and as yet we have only his conclusions—are very surprising.” Citing Pavlov’s report in Science, Morgan observed that “a full account of Pawlow’s methods” and evidence was necessary before fully interpreting his results, but much-better-designed experiments by his associates Vicari and MacDowell, and by others, rendered the Russian physiologist’s conclusions implausible. Nor did Pavlov’s conclusions comport with human experience: “How simple would our educational questions become if our children at the sound of the school bell learned their lessons in half the time their parents required! We might soon look forward to the day when the ringing of bells would endow our great grandchildren with all the experiences of the generations that had preceded them.”43
Russian geneticists also responded rapidly and critically. Kol’tsov felt compelled to refute the public endorsement of the inheritance of acquired characteristics by Russia’s most eminent scientist. In a speech to the Russian Eugenics Society in 1924 that he published shortly thereafter, he did so firmly in a tone of respectful condescension. Pavlov’s evidence was too weak to even merit refutation, but geneticists could not ignore the pronouncement of “the creator of the entire doctrine of conditional reflexes, a Nobel laureate”—although “we know that he has never worked in the field of genetics and perhaps does not imagine all the complexity of genetic questions.” Kol’tsov added that the animal trainer Vladimir Durov had informed him that Studentsov’s early trials had required an unusually long time—with 300 and then 100 repetitions—to train mice to respond to the buzzer. Durov claimed he could do so easily in three minutes. So, as Kol’tsov had earlier suggested to Pavlov, Studentsov had probably become a better mouse trainer over time. The geneticist also cited numerous Western experiments and authorities contradicting Pavlov’s conclusions and his credulous embrace of a most unlikely proposition: since CRs rested upon the creation of new reflexive paths, that is, “the development of new, most subtle structures in the brain,” the physiologist was implicitly endorsing the implausible notion that these reflexive paths (“extraordinarily specialized microscopic structures”) “could in some way be reflected in the structure of the chromosome of embryological cells and elicit corresponding changes in their genotypic elements.”44
Kol’tsov’s wife, Maria Sadovnikova-Kol’tsova, also a leading geneticist, added a detailed experimental refutation in articles of 1925 and 1926. Leningrad geneticist Filipchenko joined Kol’tsov to arrange for the translation of Morgan’s article for a 1925 booklet titled Are Acquired Characteristics Inherited? These experiments and arguments hardly converted all believers in the inheritance of acquired characteristics, but they did quickly convince Pavlov that his own experiments proved nothing.45
Kol’tsov sent Pavlov a copy of his article and, having heard that the elderly physiologist was “very impatient of criticism,” he approached him with some trepidation during the celebration in 1925 of the 200th anniversary of the founding of Russia’s Academy of Sciences. Pavlov greeted him affably with the words “Now I will work only with dogs, which I know, and want to work no more with mice.” His longtime collaborator Ganike, however, was continuing Studentsov’s research. Pavlov showed Kol’tsov Ganike’s mice, who now answered the buzzer after five to seven trials. Kol’tsov asked the same question as he had before Pavlov’s trip: had the experimenters compared the performance of the mice with “educated” forebears to that of mice with “uneducated” parents? Yes, Pavlov replied—and both groups learned at the same pace. “The misunderstanding,” recalled Kol’tsov with satisfaction, “was decisively elucidated.”46
So embarrassed was Pavlov by this episode that he encouraged Kol’tsov to believe, as the geneticist later recalled, that the offending article in Science had actually “not been written by him.” Here he was subtly shifting the blame to the translator, Boldyrev—but Boldyrev’s translation for Science was true to Studentsov’s original report and essentially identical to the English translation produced by the Pavlovs during the return cruise to Europe and presented in Edinburgh.47
Pavlov’s embarrassment grew as the scientific press publicized his claims, believers in the inheritance of acquired characteristics cited him approvingly, and eager inquiries about the final results of his experiments poured in from around the world. Major H. H. King, writing from the Central Research Institute in Punjab, India, wrote excitedly to Nature about Pavlov’s revelations at the Edinburgh congress, eliciting the editorial response that “We must await the confirmation and full exposition of the facts. But it must, in any case, be regarded as an event of the highest significance that an observer of such preeminence, and so intensely objective in his methods, should have been led even to such preliminary conclusions.” Wilhelmine Key, chief of biology and eugenics at the Race Betterment Foundation in Battle Creek, wrote to Pavlov in May 1925 of her great interest in his experiments: “You promised further data on your material, which so far as I have been able to learn, has not yet been published in this country.... I shall be very glad to hear of any new results which you now have ready for publication.”48
Jerome Davis, a controversial sociology professor at Yale Divinity School who supported unions, Soviet Communism, and the inheritance of acquired characteristics—and who had visited Pavlov’s lab in 1921—mentioned the great interest “at Yale in your experiments on the ringing of bells in feeding successive generations of white mice. Would you be willing to tell me of the results of your research in this direction since your last visit to the United States?” Indian psychology professor M. V. Gopalaswami wrote twice with searching questions about the experimental procedures leading to “your remarkable discovery re the inheritance of acquired habits in white rats.” John Kendrick, field director of the Rockefeller Institute’s International Board of Health, requested details about “your further success with the mice...I await with impatience to learn of them answering the bell with one lesson. AND THEN—NO LESSON! If you should thus arrive at proving that instinct and intelligence are one, the result would be revolutionary to all men’s intellectual and moral cogitations.”49
Finally, Pavlov publicly retracted his experimental claims. In 1927, E. S. Smirnov published a volume on Problems of the Inheritance of Acquired Characteristics in which Studentsov’s experiments and Pavlov’s enthusiastic appraisal of them were cited. Reviewing this volume for Pravda, M. L. Levin cited a letter that Pavlov had written in March 1927 to a Moscow eugenicist, V. K. Gutten, who had requested the data from Studentsov’s final trials. “The initial experiments with the hereditary transmission of conditional reflexes in white mice are not supported [by experiments] with improved methodology and stricter control, so I should not be included among the proponents of such a transmission.”50 The official newspaper of the Communist Party, which was courting Pavlov so assiduously, would hardly have printed this excerpt from his private correspondence without his permission. Pavlov clearly hoped this public disclaimer would finally put the matter to rest.
He recanted for Westerners by inserting a footnote into the English edition of his monograph on CRs, which also appeared in 1927: “Experiments which have been communicated briefly at the Edinburgh International Congress of Physiology (1923) upon hereditary facilitation of the development of some conditioned reflexes in mice have been found to be very complicated, uncertain and moreover extremely difficult to control. They are at present being subjected to further investigation under more stringent conditions. At present the question of hereditary transmission of conditioned reflexes and of the hereditary facilitation of their acquirement must be left entirely open.”51
He was thereafter extremely reluctant to stray from research upon his one tried-and-true model organism, the dog. The Studentsov affair also combined with other developments in his lab to increase his interest in the role of heredity and environment in determining the psychological qualities of animals. Ganike’s research continued for years, and although Pavlov withdrew his earlier claims, he never disavowed the inheritance of acquired characteristics itself. The question of “nature and nurture” would become central to lab investigations of nervous types in the 1920s and, by the end of that decade, to Pavlov’s plans for his new science village in Koltushi.
Upon his return to Russia, Pavlov exchanged warm letters with Cannon and Yerkes. Cannon apologized again for “your most disagreeable experiences” in New York, assured him that “these are not at all usual,” and urged his Russian friend to publish a monograph on CRs for his Western admirers. Yerkes, too, hoped that Pavlov would “not think of our country as harshly as your unfortunate experiences might seem to justify” and that he would return frequently. “If at any time I can do anything to facilitate your work I hope you will feel free to command me.”52
The shock and humiliation of his mugging soon faded, as did the acute embarrassment of his highly public error regarding the inheritance of acquired characteristics. Warm memories and enhanced collegial relations proved much more enduring legacies of Pavlov’s great journey.