The Hawthorne effect refers to the improvement in a worker's productivity that results from observation by management or researchers. The data eventually yielding this conclusion came from experiments conducted between 1924 and 1932 in the Hawthorne Works plant, owned by the Western Electric company. The experiments were originally intended to determine how different variables affected the workers' output. The Hawthorne effect, which concerns the effects of observation, was not one of the variables initially tested; conclusions about observation were drawn only later, in retrospective analyses.
The original experiments at the Hawthorne Works facility tested a variety of different factors. The researchers who conducted this research tested things like the spacing and timing of breaks, amount of payment, the length of the workday, and the allocation of food to the workers. The lead researcher, Elton Mayo, emphasized that productivity depended on organizational sociology. He used the results to argue that factors such as workplace norms and relations to managers had a strong impact on the workers' speed.
It was only in later analysis of the data that the Hawthorne effect was isolated and given a specific name. Henry Landsberger, in 1958, published a book called Hawthorne Revisited that named and specifically described the effects of pure observation. Landsberger also noted that workers seemed to work harder after any change in protocol, even if this change simply represented a reversion to previous procedure.
The Hawthorne effect provided the theoretical foundation for the corporate field of human relations. It introduced the idea that paying attention to workers, even if this attention is extremely passive, can increase motivation. The idea of the Hawthorne effect thus provided a justification for layers of corporate structure responsible not for managing per se, but simply for paying attention.
The existence of the Hawthorne effect also served as a warning sign for researchers in the social sciences. Specifically, it indicates that care must be taken when designing experiments to compare one type of change to another type of change, rather than to no type of change at all. Otherwise, an experiment might associate a false positive with one specific variable rather than with the effect of variation in general.
Later evidence has called the size of the Hawthorne effect into question. A recent article published in the Economist suggests that the Hawthorne effect itself ignores certain other features of an experiment. For example, if variables are always changed over the weekend, changes attributed to the Hawthorne effect always occur on Monday. The article suggests that increased productivity always occurs on Monday regardless of experimental observation. Nevertheless, the Hawthorne effect has become a fundamental principle in corporate psychology and sociology.