Was There Really a Hawthorne Effect at the Hawthorne Plant? An Analysis of the Original Illumination Experiments

The “Hawthorne effect” draws its name from a landmark set of studies conducted at the Hawthorne plant in the 1920s. The data from the first and most influential of these studies, the “Illumination Experiment,” were never formally analyzed and were thought to have been destroyed. Our research has uncovered these data. Existing descriptions of supposedly remarkable data patterns prove to be entirely fictional. We do find more subtle manifestations of possible Hawthorne effects. We also propose a new means of testing for Hawthorne effects based on excess responsiveness to experimenter-induced variations relative to naturally occurring variation. (JEL C90, J24, J28, M12, M54, N32)