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The Hawthorne Effect

In this article, we’re going to cover the basics of the Hawthorne effect, an interesting phenomenon where people behave differently when they know they’re being observed. We’re also going to break down some of the most important experiments and studies that were done on the subject, as well as some alternative explanations that were hypothesized throughout the years.

What is the Hawthorne Effect?

To put it simply, the Hawthorne Effect refers to the change or increase in performance by individuals once they become aware of the fact that they’re being watched, noticed, or paid attention to by supervisors or researchers. The term was coined in 1958 by Henry A. Landsberger while doing evaluations of several studies at Western Electric’s Hawthorne Works, a plant near Chicago, Illinois.

The studies that were done at the plant featured a research team consisting of several scientists and company representatives, including Mayo, Roethlisberger, Whitehead, and Dickson. The so-called Hawthorne studies consisted of four separate experiments:

  1. Illumination Experiments

  2. Relay Assembly Test Room Experiments

  3. Experiments in Interviewing Workers

  4. Bank Wiring Room Experiments (Perera, 2021)

Experiments & Studies

1. Illumination Experiments

Conducted between 1924 and 1927, this was the most influential experiment done on the subject of the Hawthorne Effect. The purpose of the experiment was to establish whether there was a connection between the work environment and productivity. More specifically, they wanted to see whether the level of lighting in a factory would impact the productivity levels of the employees.

To begin with, the first group of workers making electrical relays was subjected to several lighting changes throughout their shift, and their performance was observed in response to the changes. The study found that any change in lighting, regardless of whether it was a positive or negative change, led to a boost in productivity. However, the study also found that productivity dipped again once the attention faded, which implied that the increase was a direct result of a motivation effect. To summarize, the fact that the employees knew that they were being observed led to an increase in job performance (Perera, 2021).

2. Relay Assembly Test Room Experiments

Following the initial findings, more experiments were conducted at the same plant over the following eight years. The researchers focused on examining changes in rest periods, the average length of the workday, physical conditions, and overall work structure. The initial findings were reinforced when the results were summarized: An increase in performance was apparent when individuals were noticed, watched, or supervised by researchers or their supervisors.

The remaining experiments and studies, which were conducted up until 1932, all confirmed the previously hypothesized theory and finally, the term the Hawthorne Effect was coined in 1958 (Perera, 2021).

3. Experiments in Interviewing Workers

Between 1928 and 1930, approximately 20,000 interviews were conducted during the course of the experiments. The purpose of these interviews was to determine the employees’ attitudes towards the company, wages, supervision, promotions, etc. This interview experiment provided researchers with valuable information on the overall behavior across the company.

4. Bank Wiring Room Experiments

The purpose of this study was to determine if and how payment incentives would affect productivity. Conducted between 1931 and 1932, the experiment featured a group of fourteen men who were in charge of putting together telephone switching equipment. It was concluded that the productivity of the workers did not improve despite the incentives due to a variety of social factors (Chand, 2014).

Alternative Explanations

Even though it was observed that the Hawthorne effect had a significant impact on the behavior of the participants during the experiments, it should be noted that there may be other factors that influence these changes in behavior. Other possible explanations are explained in more detail below.

Demand Characteristics

This alternative explanation refers to the fact that the researchers occasionally hinted at what they were trying to prove during the experiments. The result of displaying these subtle clues was a change in the behavior of the participants that helped confirm the hypothesis of the study.

Novelty Effects

The fact that the experiments were something that the participants did not experience before might have had an impact on their behavior. The novelty of having observers might have led to an increase in both productivity and performance, but it eventually leveled off as the experiments continued.

Performance Feedback

In those experiments that involved the productivity of the workers, increased attention that was given to them by the researchers might have resulted in increased performance feedback. This increase in performance feedback might have further led to a significant improvement in terms of the overall productivity of the workers (Cherry, 2020).

Results and Impact

After a detailed systematic review and investigation of all studies performed on the subject, the results showed a wide variation range in the proposed Hawthorne effect. Even though no summary of the overall impact could be provided, it was determined that research participation did in fact influence the behavior of the workers, at least to some extent and in some circumstances (Hawthorne Effect, 2021).


To summarize, it was determined that behavior was impacted by research participation, but there is little that can be securely known about the overall conditions, mechanisms of effects, and magnitude. It is generally thought that new studies and concepts are needed in order to guide empirical studies (McCambridge et al., 2014).

Reference List

Chand, S. (2014, February 24). 4 Phases of Hawthorne Experiments – Discussed! | Business Management. Your Article Library. Retrieved April 21, 2022, from

Cherry, K. (2020, October 13). How Does the Hawthorne Effect Influence Productivity? Verywell Mind. Retrieved April 21, 2022, from

Hawthorne effect. (2021, November 20). Catalog of Bias. Retrieved April 18, 2022, from

McCambridge, J., Witton, J., & Elbourne, D. R. (2014). Systematic review of the Hawthorne effect: New concepts are needed to study research participation effects. Journal of Clinical Epidemiology, 67(3), 267–277.

Perera, A. (2021, May 28). What is the Hawthorne Effect? | Simply Psychology. Simply Psychology. Retrieved April 18, 2022, from

Authored by:

Nina M Benjamin Silber

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1 Comment

michelle crowley
michelle crowley
May 18, 2022

Whether the Hawthorne effect has validity has huge implications for research in the soft (social) sciences. The data are ideas and perceptions, which makes defending any psychological explanation in court a nightmare and is why legal teams so often shred psychologists who have the courage to present their assessment of an accused. But the deeper issue is that when conducting research, one is expected to inform participants about both what one is researching and how it might affect them so that participants can give their voluntary consent to participate. I often read consent forms that almost tell the participant what the research expects to find. So, one has to wonder about the validity of a great deal of soft science…

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