Background

Thurstone was born on May 29, 1887 in Chicago, Ill. He was the son of Swedish immigrants Conrad and Sophie Stroth Thurstone. His father was a Lutheran minister and a newspaper editor and publisher. The family lived in several communities, including , N. Y.

Education

Thurstone graduated from high school in Jamestown. He then attended Cornell University, receiving a degree in mechanical engineering in 1912. While at Cornell, he invented a flickerless motion-picture projector. He demonstrated it to Thomas A. Edison, who did not choose to produce it but offered the young engineer a position in his East Orange, N. J. , laboratory. Thurstone worked there during the summer of 1912 and then took an instructorship in drafting and descriptive geometry at the University of Minnesota.

He gradually became more interested in psychology and enrolled as a graduate student in that subject at the University of Chicago in 1914. Three years later he received the doctorate.

He recieved a Honorary Doctorate from the University of Göteborg (1954).

Career

In 1915, Thurstone had accepted an assistantship in psychology at the Carnegie Institute of Technology in Pittsburgh, Pa. After 1917 he rose rapidly, eventually becoming full professor and the head of the department. His work during those years was primarily in designing tests, including oral trade-aptitude tests for the army during World War I and college entrance examinations for the American Council of Education.

In 1924 Thurstone returned to the University of Chicago as associate professor of psychology, and three years later he was promoted to full professor. He developed a psychometric laboratory, formally so called in 1930.

A founder of the Psychometric Society and of its journal, Psychometrika, he served as its first president in 1936. In 1938 Thurstone was named Charles F. Grey distinguished service professor. He retired in 1952. These events, together with scores of articles and monographs, were the signposts of a distinguished research career that made Thurstone one of the most respected and one of the most frequently cited American psychologists.

His investigations, most of which involved developing and applying mathematical ways of measuring mental activity, extended to test theory, identification of primary mental abilities, the basic theory of measuring attitudes (law of comparative judgment), and the study of attitudes, values, creativity, personality, and temperament. Thurstone had done enough work in designing psychological tests to recognize that a fuller understanding of the basic theory was needed, and his research at Chicago began in this area. In several papers written during the 1920's he explored the theory of scaling tests, the significance of the dispersion of the scores of different groups as well as the means of their scores, the mental-age concept, and other aspects of test theory.

A matter of major concern to psychologists during that period was the nature of intelligence and how it could be measured. Some had assumed a single entity. Charles Spearman, a British psychologist, had suggested that all cognitive behavior can be accounted for by postulating two factors, a general type of intelligence that is involved in all mental activity and an undetermined number of lesser specific factors that enter into corresponding specific activities. Thurstone approached the matter as a problem in multiple correlation. If subjects perform a large variety of tasks, such as taking a large number of tests, what is the minimum number of factors necessary to account for the correlations disclosed by the results? In his major study, conducted in 1934, he analyzed the results of fifty-seven tests administered to 240 students and concluded that they demonstrated the existence of seven primary mental abilities: numerical ability, spatial visualization, perceptual speed, rote memory, verbal meaning, verbal fluency, and reasoning. Other researchers have grouped their materials differently and have spoken of four, or eighty-two, or more than a hundred factors, but whatever the number, intelligence is now seldom if ever regarded as a single entity. Perhaps more important--for others were also moving away from the single-entity concept of intelligence--was Thurstone's method of handling large quantities of data. Using matrix algebra he developed the theory and procedures of multiple-factor analysis, widely used ever since in the study of mental characteristics in general.

Developing this system and applying it in identifying primary mental abilities absorbed Thurstone's major efforts over a period of twenty years. He and others have used it in studies of personality, creativity, temperament, and other broad human characteristics. The Vectors of Mind (1935) and Multiple-Factor Analysis (1947) are probably his most important works in this field.

Another closely related area of innovation involved a fundamental extension of psychophysics. This term had been used in the nineteenth century to indicate the study of the relation between physical stimulus and mental response--for example, how much a sound must be increased in volume for a subject to be able to detect a difference in intensity--and two basic principles had been enunciated by Ernst Weber and Gustav Fechner.

Thurstone, who was interested in measuring such mental responses as social, moral, or aesthetic evaluations, saw here an essentially similar kind of problem, but one that would extend psychophysics into an uncharted area. Again, basic theory was needed. Simultaneously, his work clarified Weber's and Fechner's laws, extended the field to include mental responses to mental stimuli, and provided a basis for the quantitative study of social attitudes and other matters that had previously been handled only descriptively.

His "Law of Comparative Judgment" (1927) provides a mathematical principle for testing internal consistency in studies of this nature. Years later he considered this his most important paper. The idea that "Attitudes Can Be Measured" (as he titled a 1928 article) was intriguing but not obviously correct. Thurstone supported his theories by completing studies that demonstrated the measurement of religious attitudes, attitudes toward ethnic groups, and the effect of motion pictures on children's attitudes. He foresaw that careful surveys might not only inform researchers as to existing public attitudes, but also help them predict what choices people would probably make, and why.

Stimulated by teaching, Thurstone was convinced that he could accomplish more by devoting part of his time to the classroom than by spending all of it on research. Meticulous in his own scholarship, he was patient with students struggling to grasp or to express new concepts; but he was decisive and sometimes blunt, apt to be outspokenly critical of students or colleagues whose verbal fluency cloaked a dearth of ideas. He was not, therefore, a universally beloved figure, but he was widely esteemed. His seminars attracted outstanding students, including many foreign and postdoctoral scholars. He served as visiting professor at Frankfurt in 1948 and at Stockholm in 1954.

Following Thurstone's retirement in 1952, he and his wife joined the faculty of the University of North Carolina and established a psychometric laboratory there. He died at Chapel Hill, N. C. ; his widow continued to direct the laboratory until 1957.

Achievements

• Louis Leon Thurstone conceived the approach to measurement known as the law of comparative judgment, and is well known for his contributions to factor analysis. A Review of General Psychology survey, published in 2002, ranked Thurstone as the 88th most cited psychologist of the 20th century, tied with John Garcia, James J. Gibson, David Rumelhart, Margaret Floy Washburn, and Robert S. Woodworth. Thurstone received numerous awards, including: Best Article, American Psychological Association (1949); Centennial Award, Northwestern University (1951).

Works

More photos

• book

  • Motion Pictures and the Social Attitudes of Children

    ( This work has been selected by scholars as being cultur...)

  • Multiple-Factor Analysis: A Development & Expansion of The Vectors of Mind

    (Correcting much of the misinterpretation which arose from...)

  • The Vectors Of The Mind: Multiple Factor Analysis For The Isolation Of Primary Traits

    (University Of Chicago Science Series.)

  • Primary Mental Abilities (psychometric monographs)

    ("a form of test in current use")

  • The Nature of Intelligence
  • The Fundamentals of Statistics

Membership

He was made an honorary fellow of the British and Swedish psychological societies.

Thurstone was President of American Psychological Association (1933) and first President of the American Psychometric Society (1936).

Connections

In 1924 he married Thelma Gwinn, who had assisted him in the preparation of the ACE tests. She received the Ph. D. in psychology in 1926 and collaborated with her husband on many research projects and publications. They had three sons.

Father:

Conrad Thurstone

Mother:

Sophie Stroth Thurstone

Spouse:

Thelma Gwinn

References

• A History of Psychology in Autobiography, Volume IV
• Louis Leon Thurstone;: Creative thinker, dedicated teacher, eminent psychologist