Single-Case Research

A Brief History of Early Single-Case Research in Psychological Science

Although individuals with mental retardation (MR), developmental disabilities, and psychopathology were known to ancient civilizations—in particular, nearly all those born with identifiable congenital defects and likely killed soon thereafter—there were few societal mechanisms by which to accommodate individuals who suffered from these disorders. The earliest clinics in Western civilization were probably founded after the Council of Nicæa met in the 4th century and decreed that Christians provide lodging for those unable to care for themselves. In the 17th century, the largest hospital in Paris, the Hôtel Dieu, was ordered to house individuals with psychopathology or MR. Elsewhere in Europe, however, such individuals were treated either as curiosities and tourist attractions, as they were in England—or worse, demonized and tortured, as they were in France and Germany.

One of the earliest descriptions of adult clinical applications in single cases refers to the mid-18th-century efforts by Jacob Pereira to teach an adolescent deaf-mute to speak. Pereira's individualized approach used, among other things, the sense of touch. His methods were embraced by Edouard Seguin and Jean Itard, the latter of whom attempted to socialize a putatively feral 12-year-old male, Victor of Aveyron. Seguin, a student of Itard's, went on to develop his own system of individualized instruction, in which each child was evaluated and training exercises developed according to his or her own observed strengths and weaknesses, procedures surprisingly reminiscent of the current techniques used by applied behavior analysts.

Elsewhere in France during the late 18th to early 19th century, Philippe Pinel established new, more humane approaches to the treatment of individuals with mental disorders. In the mid-19th century, Dorothea Dix brought about similar changes in the United States, separating individuals who were mentally impaired from those who were either indigent or criminals. One of the earliest-known applications of a behavioral cure for individuals with psychological disorders was the use of hypnosis, employed during the late 18th to early 19th century by the physician, Antoine Mesmer. Mesmer worked with groups of people, but his student, the Marquis de Puységur, actually hypnotized individuals and, after talking to them during their somnambulant trances, claimed to be able to relieve them of their ailments. Later, Jean Charcot, a neurologist, utilized hypnosis as a therapy with his patients whom he had diagnosed with hysteria to rid them of their somatic symptoms. Sigmund Freud, who learned to use hypnosis from Charcot and initially employed it with his patients as a “talking cure” (catharsis), replaced it with his verbal technique of free association.

Evaluation of individuals and treatment of human disorders was very much a 19th-century phenomenon, particularly the assessment of human development and intelligence. Observational studies of infants by Charles Darwin and other notable figures of the time were published, and individual differences in their patterns of development noted. The first tests of intelligence devised by Alfred Binet and Theodore Simon were used to separate normally developing children from those with special needs. And although trained originally to study maze behavior in the rat, John B. Watson later adapted his stimulus-response behavioral techniques to condition human infants.

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