Intended for healthcare professionals

Rapid response to:

Endgames Statistical Question

The Hawthorne effect

BMJ 2012; 344 doi: (Published 04 January 2012) Cite this as: BMJ 2012;344:d8262

Rapid Response:

Re: The Hawthorne effect

The discussion is certainly not dead yet. To conclude that “the evidence for the Hawthorne effect was perhaps far more subtle than previously acknowledged” leaves out the preceding sentences in the article, available on line at

To quote directly, “Both academics and popular writers commonly summarize the results as showing that every change in light, even those that made the room dimmer, had the effect of increasing productivity. The data from the illumination experiments, however, were never formally analyzed and were thought to have been destroyed. Our research has uncovered these data. We find that existing descriptions of supposedly remarkable data patterns prove to be entirely fictional”.

It was an early example of publication bias. The electric company that sponsored the studies wanted to show that increased lighting improved productivity, and so would increase electricity use. The results were abandoned when they could not show that. There was only cursory analysis leading to the wrong conclusions which have persisted. With selective misquoting the myth may well persist.

Competing interests: No competing interests

11 April 2012
Brendon J Smith
Emergency physician
Bankstown-Lidcombe Hospital
Eldridge Road, Bankstown, NSW, 2200, Australia