Word association is connected with the work that Carl Gustav Jung was engaged in at the Burghölzli Psychiatric Clinic of the University of Zurich in the early stages of his career (Jung, 1917/1926/1943). Under the directorship of Eugen Bleuler, the Burghölzli Psychiatric Clinic was an international center of excellence in psychiatric research at the turn of the century. Jung became director of research on the Word Association Test. This test usually consisted of a hundred stimulus words that were read out singly to a subject who was to "answer as quickly as possible with the first word that occurs to you." The reaction time, verbal response, and test behavior were recorded and analyzed. Verbal responses were classified according to several linguistic categories. The test was used to diagnose psychological typology and psychopathology.
Jung introduced significant innovations to this method. In addition to the cognitive dimensions, he emphasized the emotional aspects involved. He noted that the words to which subjects offered unusual responses were connected with themes having an emotional impact on them. He found that subjects invariably do not have conscious control over their responses. Therefore, he argued, this method was tapping both conscious and unconscious phenomena. He found that clusters of ideas, images, and words loaded with much affect (positive or negative) interfered with the ego (as the coordinating agency) by producing unusual responses. He called these clusters complexes. Jung used Freud's theories of repression to account for the autonomous nature of complexes. Freud praised Jung for providing experimental proof of the existence of the unconscious, welcoming him in the early psychoanalytic movement as a much needed hard-nosed scientist. Although the term complex was used by Freud and Josef Breuer earlier, it was with Jung's meaning that it finally entered the psychoanalytic vocabulary.
Jung and his associates applied the Word Association Test to many psychiatric contexts, including forensic diagnoses, publishing some remarkable cases of successful detection. A much-neglected facet of Jung's early work is his application of this method to families. He gave the test to members of the same families and found that there were psychological subgroupings in the same family. At the time, however, Jung possessed neither the theoretical understanding nor the clinical experience to take these findings further. One can argue that these unfinished questions contributed to the development of his theories about other manifestations of shared unconscious structures in subjects, for example, the archetypes (Papadopoulos, 1996).
Gradually, Jung abandoned this method and the whole experimental approach to psychiatry, especially after leaving the Burghölzli Psychiatric Clinic. Nonetheless, his method of amplification (instead of free association) and his sensitivity to the role of language in psychotherapy owe their origin to the Word Association Test. As of 2005, the Word Association Test is hardly used, though it is taught in some Jungian training programs and some analysts use it as a technique to enhance the therapeutic process (Hill, 1975).