Harry L. Hollingworth

Harry Levi Hollingworth (May 26, 1880 – September 17, 1956) was one of the first psychologists to bring psychology into the advertising world, as well as a pioneer in applied psychology.

Following his graduation Hollingworth took an instructor’s position at Barnard College, teaching psychology and logic.

The Coca-Cola Company, facing a lawsuit from the federal government under the Pure Food and Drug Act, approached Hollingworth (after James McKeen Cattell and several other psychologists turned them down) about investigating the psychological effects of caffeine on humans. Aware of the stigma associated with applied work, as well as possible concerns about the scientific integrity of research funded by a corporation, Hollingworth included several conditions in his contract with Coca-Cola. Specifically, Hollingworth stated that Coca-Cola could not use the results of his research in its advertisements, nor could Hollingworth’s name or that of Columbia University be used in these ads. Additionally, Hollingworth was free to publish the results of his research regardless of the outcome of the study. Furthermore, to reduce any questions about the integrity of his research Hollingworth designed his three caffeine studies to include blind and double-blind conditions. The scope and methodology employed in these studies had never before been seen applied to psychological research.