This one gets repeated everywhere. When researchers went back and checked the original evidence, it did not hold up. The popular version is not what the data actually shows.
In 1927, Western Electric's Hawthorne Works in Cicero, outside Chicago, moved five young women off the assembly floor into a separate test room, with a sixth to lay out the parts, to assemble telephone relays while researchers recorded everything they did. The company wanted to know how rest breaks, hours and meals affected output. The study ran for five years, the longest of the Hawthorne experiments, and output rose. In 1928, the engineer running it brought in Elton Mayo of Harvard Business School to explain why. Mayo's reading was that the six "became a team" and gave themselves wholeheartedly to the experiment, and from that reading came the human relations school of management: supervision, attitude and the feeling of the group as the keys to productivity.
The company's own records show several other things changing at the same time. After the first two experimental periods, the women's group incentive, which on the floor had been based on the output of more than a hundred workers, was based on the five of them instead, so each woman's own output mattered far more to her pay. In the second year, two of the five were removed from the room because management found them too talkative and uncooperative, and were replaced by two more productive workers, one of whom became the group's informal leader. The Depression arrived halfway through. In 1978, Franke and Kaul ran the first statistical analysis of the five years of data and argued that the replacement of the two workers and the Depression explained most of the variation in output, an analysis that has been disputed since but never overturned. In 1983, two of the original operators, interviewed fifty years on, remembered the room with affection and the freedom it gave them from the floor supervisors, and said that pay, which they recalled rising to between $28 and $50 a week, had mattered a great deal.
The phrase "Hawthorne effect" was coined in 1953, in a research methods textbook, 26 years after the test room opened. The image it carries, output rising whether the lights went up or down, comes from separate, earlier lighting experiments at the same plant, whose data was assumed lost until Levitt and List found it and re-analysed it in 2011. The lighting changes had been made on Sundays, the plant's day off. Output rose on Mondays whether the lights had changed or not, and improved over time as workers gained experience. The dramatic effect was not in the data.
A finding can be taught for eighty years and still not be supported by its own records, because the lesson that gets repeated is the one that is cheapest to act on. Attention costs a company less than money, so the version of Hawthorne that survived was the one about attention, and the pay change, the replacements and the Depression dropped out of the telling.
Being observed can change behaviour. A 2014 systematic review found evidence that taking part in a study can change what people do, but concluded that the size and the conditions of the effect remain uncertain. What is false is the specific famous story, and the lesson built on it. So when someone explains a change in output by how people felt, ask what changed in their pay, their hours, their supervision and who was in the room. Those were moving at Hawthorne too, and they are usually moving in your company. Repetition is not evidence, and something being said everywhere for a long time is not the same as it being true.
Source: The re-analysis of the lighting data: Levitt and List, 2011, American Economic Journal: Applied Economics. The relay room: Roethlisberger and Dickson, Management and the Worker, 1939, and Harvard Business School's Baker Library account of the studies. The pay change: Parsons, What Happened at Hawthorne?, Science, 1974. The statistical re-analysis: Franke and Kaul, The Hawthorne Experiments: First Statistical Interpretation, American Sociological Review, 1978. The participants' own accounts: Greenwood, Bolton and Greenwood, Hawthorne a Half Century Later, Journal of Management, 1983. The review: McCambridge, Witton and Elbourne, 2014, Journal of Clinical Epidemiology.
Jim Manzi, 2012
On why rigorous testing matters, and how much accepted wisdom does not survive an honest re-examination.
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