By Jim Owens PMP



The Hawthorne Effect was extrapolated from, and some years after, research performed by Professor Elton Mayo and his team, in the Hawthorne plant of Western Electric, between the years 1927 and 1932. The research attempted to measure the effect of changing physical setting of working conditions on staff performance. It is suggested that the Hawthorne Effect affects outcomes because the subjects of an experimental intervention are aware that they are being observed and because they are receiving extra attention. Experts are divided on the veracity of the Hawthorne Effect, whilst others accept the conclusion, but reject the experiments as an unsuitable means for proving it.

The Hawthorne Effect



Professor Elton Mayo of Harvard University led a team of researchers that conducted a series of experiments at the Hawthorne plant of Western Electric, at Cicero Illinois, between the years 1927 and 1932.

Robbins (1988) says that the Hawthorn Effect was not derived at the time the studies were performed, but was extrapolated later from the results of three groups of illumination experiments carried out at Hawthorne. These results are often offered as proof of the theory.

The suggestion is that increasing illumination levels for the experimental group resulted in increased performance, but subsequent and significant reductions in illumination levels, produced further increases in performance, thereby proving that a group under examination will perform better simply from the knowledge that they are being observed, and because of special attention they receive from management, researchers and peers. That is the effects on performance are psychological.

Harris (2002) gives a synopsis of the Effect, as is generally accepted, The Hawthorne Effect was formulated during the first time-management study, circa 1932, that included employee opinions and preferences.

Psychologists, at the Chicago-based Hawthorne Plant of Western Electric, employed a variety of interventions to improve employee morale and productivity (Diaper, 1990). Independent variables included variations in levels of lighting, room temperature. and length and scheduling of rest periods. Improved morale and increased productivity were observed, temporarily, in response to each of the interventions. Consequently, it was concluded that the experiment, itself, i.e., interest in and involvement of the employees, induced positive attitudinal and behavioral responses. The outcomes of the experiment became known as the Hawthorne Effect, i.e., any change in the physical environment or social interaction that includes input by the target audience is likely to induce, at least temporarily, measurable changes in attitude or behavior.

Adair et al (1989), quoting Adair (1984), isolated the features of the methodology that led to the Effect, Examination of Hawthorne control practices of educational researchers indicates that three salient features of the original studies have been identified as the primary source of the methodological artefact: the special attention subjects received from their observers and supervisors; awareness of their participation in an experiment; and the novelty or unique features of the experimental activity (Adair, 1984).

However Merrett (2006) suggests that the experiments results from the Hawthorne experiments do not necessarily support the theory, The results of these experiments indicated not only that experimental groups who worked with progressively greater illumination produced more (which was fully expected) but that groups produced more who did not have more illumination, and indeed even those groups whose illumination was progressively decreased produced more. Whatever the relation between illumination and productivity, it could not be disentangled from the influence of other variables. No detailed interpretation of these seemingly contradictory results was, therefore, attempted.

Adair et al (1989) performed a set of 86 experiments to test the Hawthorne Effect, from which they concluded, there was no evidence of an overall Hawthorne effect. The mean effect associated with Hawthorne manipulations was non-significant, and hence such groups essentially could be regarded as no different from a no-treatment control. Moreover, a detailed analysis of these studies by their control procedure, and subsequently by other moderator variables, also revealed no systematic trends to suggest a specific artefact to pose as an alternative concern.

Others suggest that the Hawthorne Effect is no more that a legend, for example Occupational Medicine (2006), quoting Gale EAM. The Hawthorne studiesa fable for our times? Q J Med 2004;97:439449, states These at least seem to be the main facts behind the popular legend, although these particular experiments were never written up, the original study reports were lost, and the only contemporary account of them derives from a few paragraphs in a trade journal.

Despite concern with the veracity of the Hawthorne Effect however, if is still often quoted in contemporary research, for example Tan (2004) on the Effects of Background Music on Quality of Sleep in Elementary School Children, Another explanation for the significant experimental effect could be attributed to a Hawthorne effect. In other words, there is a possibility that subjects might be responding to the treatment due to their awareness of participation. This might also be the explanation for why subjects in the control group also showed improvement in their sleep quality.

So whether the Hawthorne Effect actually exists or not is uncertain, but even if it does, it is not viewed by some as a valid conclusion from the original experiments performed at Hawthorne, even if they could be found.

About the Author: Jim Owens PMP is a career Project Manager, presenter and PMP instructor. Jim is director of Certification with PMI Western Australia Chapter, Columnist with

and Information Age Magazine. Visit Jims website

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