The Hawthorne effect
Abstract
LETTERS TO THE EDITOR 217 doi:10.1093/occmed/kqj046 âThe consumer of knowledge can never know what a dicky thing knowledge is until he has tried to produce itâ; F. J. Roethlisberger, investigator at Hawthorne. The Hawthorne effect is a familiar anecdote to occupational physicians given that it relates to experiments with improved factory lighting which increased the productivity of workers. Incrementally increasing the level of lighting brought about increased output until someone reduced the level below baseline and output increased still further. The moral of the Hawthorne effect is that people change their behaviour when they think you are watching it and this principle has wider implications in medicine to describe the improved health of control groups. But how many of us know the origins of the fable? Gale [1] recounts the story and its background in a fascinating piece of occupational medicine archaeology: âThe story relates to the ï¬rst of many experiments performed at the Hawthorne works of the Western Electric Company in Chicago from November 1924 onwards. The original aim was to test claims that brighter lighting increased productivity, but uncontrolled studies proved uninterpretable. The workers were therefore divided into matched control and test groups and, to the