Show Summary Details

Page of
<p>Printed from American National Biography. Under the terms of the licence agreement, an individual user may print out a single article for personal use (for details see <a href="" target="_blank">Privacy Policy</a> and <a href="/page/legal-notice" target="_blank">Legal Notice</a>).</p><p> Subscriber: null; date: 24 July 2019</p>

Sidis, Borislocked

(12 October 1867–24 October 1923)
  • Eugene Taylor

Sidis, Boris (12 October 1867–24 October 1923), psychologist, physician, and pioneer in the field of psychopathology, was born in Kiev, Russia, the son of Moses Sidis, a well-to-do merchant and intellectual, and Mary Marmor, both Ukranian Jews. Under his father’s tutelage, Boris showed early intellectual promise, developing an interest in poetry, languages, and history. During the czarist pogroms against the Jews in the 1880s, he was arrested for teaching peasants how to read and write. He spent two years in solitary confinement and withstood beating and torture before his father was able to secure his freedom. He immediately escaped from Russia and went, nearly penniless, to New York in 1887. While tutoring Russian immigrants, he met Sarah Mandelbaum. In 1891 Sidis went on to Boston, where Mandelbaum soon joined him. She enrolled at the Boston University Medical School, and he continued to work and study. At her urging, he qualified to enter Harvard as a special student in 1892, and he received an A.B. in 1894. Also in 1894 he married Mandelbaum; they had two children.

Sidis attracted the friendly attention of the Harvard philosopher-psychologist William James, who encouraged him to enter psychology. Under James’s guidance, Sidis earned an M.A. in 1895 and a Ph.D. in 1897. His dissertation, The Psychology of Suggestion, a treatise on the hypnotic suggestibility of crowds, was signed by George Herbert Palmer, Josiah Royce, and E. B. Dellabarre, in addition to James. Published by Appleton in 1898 with a preface by James, the work subsequently launched the so-called Boston school of psychotherapy and also had a major impact on the continued evolution of experimental social psychology in France.

After leaving Harvard, through a contact that James had with a former student, Theodore Roosevelt, then governor of New York, Sidis became an associate in psychopathology at the recently established Pathological Institute of the New York State Hospitals under Ira van Gieson. While there, Sidis influenced such budding psychotherapists as William Alanson White. In 1901 Sidis became director of the psychopathic hospital and laboratory at the New York Infirmary for Women and Children.

During this time, Sidis embarked on a systematic experimental analysis of the subconscious, particularly focusing on the diagnosis of multiple personality. From this research, he produced an in-depth study of a single case, Rev. Thomas C. Hanna, who, after a severe accident, had become a dual personality. Hanna’s life was one identity before the accident and a completely different one after. Through Sidis’s intervention, however, the personalities were successfully merged, and the case of Hanna, described in Sidis’s work with S. P. Goodhart, Multiple Personality (1904), became a milestone in the scientific literature on dissociation, the reigning theory of the subconscious, which posited mental states as either integrated or dissociated from one another. Sidis’s various works on psychotherapy and the subconscious soon became internationally known as standard texts in the field.

Sidis returned to Harvard in 1904 and began work on an M.D., studying primarily under neurologist James Jackson Putnam. He also came under the influence of the physiologist Walter Bradford Cannon. Sidis’s perspective on psychotherapy thus became more biological and psychiatric. He lived in Brookline with his wife and young son, William James Sidis, who later became known as a prodigy, and he maintained a private practice in psychotherapy while he went to medical school.

Beginning in 1904, Sidis rendered translations of Ivan Petrovich Pavlov and Sigmund Freud for the staff at the Massachusetts General Hospital (with the assistance of the young Dr. Harry Linenthal). Sidis’s most important studies at this time, however, were on hallucinations, sleep, and the galvanometric measurement of psychophysical responses. He crowned this period with articles in the Journal of Abnormal Psychology in which he described a method subsequently used widely by psychopathologists to tap into forgotten subconscious memories. Using light hypnosis, the method involved suspending consciousness between waking and sleeping in the so-called hypnogogic state, where abstract thoughts could be translated into prolific mental images.

Sidis received an M.D. from Harvard in 1908 and a year later opened the Sidis Psychotherapeutic Institute in Portsmouth, New Hampshire. The facility encompassed a palatial estate, complete with rolling fields, well-trimmed lawns, large spouting fountains, and numerous elegant buildings. Previously called “Maple Wood Farms,” the house and grounds had been given to him by a grateful patient, Mrs. Frank Jones, to establish a private hospital that employed the latest psychotherapeutic techniques from Europe and America for wealthy neurasthenic patients.

From this vantage point, for the following decade and a half, Sidis continued to work and publish on scientific psychotherapy, a field that already was rapidly changing toward the radically different model of Freudian psychoanalysis and away from the classic nineteenth-century model of dissociation, to which he had so mightily contributed. Nevertheless, Sidis continued to publish treatises on psychotherapy, among them The Foundations of Normal and Abnormal Psychology (1914), Symptomatology, Psychognosis, and Diagnosis of Psychopathic Diseases (1914), and The Causation and Treatment of Psychopathic Diseases (1916).

Meanwhile, Sidis also branched out into psychology and education with his Philistine and Genius (1911) and into psychology and literature with The Psychology of Laughter (1913). He was also passionately interested in languages, political economics, and philosophy.

Personally, according to his friend and colleague Linenthal, “he possessed a genial and kindly nature, but was apt to express his opposition to what he considered fraudulent or dishonest with abruptness and vigor.” Sidis died suddenly of a cerebral hemorrhage in Portsmouth.


The most complete bibliography of Sidis’s books and articles is on file in the Rare Books Department, Countway Library of Medicine, at Harvard Medical School. A less complete version is in the Twenty-fifth Anniversary Report of the Harvard Class of 1894 (1919). Still the best statement on Sidis’s personality is the entry by Harry Linenthal in The Dictionary of American Biography. Additional biographical details of Sidis’s life can be gleaned (with some caution) from Amy Wallace, The Prodigy (1986), a biography of the son, William James Sidis. The psychotherapeutic scene in which Sidis operated has been circumscribed in George E. Gifford, Jr., Psychoanalysis, Psychotherapy, and the New England Medical Scene, 1894–1944 (1978); Nathan G. Hale, Jr., Freud and the Americans: The Beginnings of Psychoanalysis in the United States, 1876–1917 (1971); and E. I. Taylor, William James on Exceptional Mental States (1982). Obituaries are in the Portsmouth (N.H.) Herald, the Boston Transcript, and the New York Times, 25 Oct. 1923.