The Hawthorne Effect is a phenomenon whereby subjects in an experimental study improve their performance or change their behavior simply because they are being monitored or studied. It was first noted in the early 1920s, during the so-called Hawthorne Experiments, run by researchers at Western Electric’s factory in the Hawthorne suburb of Chicago.

The Hawthorne Experiments were conducted to assess the effect of changes in industrial conditions on worker productivity. Researchers found that worker’s productivity increased when the lighting in the workplace was increased, but then improved further even after the lights were decreased. This drove home the point that just the fact that someone was monitoring or noticing the workers' behavior had an impact on performance.

It is thought that the Hawthorne Effect is caused by a combination of factors, such as the psychological impact of increased attention or a sense of community that comes with being part of a group being studied. Additionally, the expectation that a change will be implemented, regardless of the outcome of the research, can create a kind of ‘halo effect’, where people strive to prove the researcher’s hypothesis.

The Hawthorne Effect may also play a role in leading to more meaningful results in other types of studies beyond workplace productivity, such as public health issues, classroom behavior and even elections, as people are more likely to change their behaviors when they know they’re being watched.

The debate over whether the Hawthorne Effect is real remains ongoing. Some researchers have contended that the experiments were flawed, as researchers changed variables without truly adjusting the environment of the facility in question. However, many of the explanations put forward by the researchers – such as the sense of community and pushed expectations – still provide valuable insights into the effects of observation on behavior.

As it stands, the Hawthorne Effect provides an important reminder that results from studies can be affected by the conditions in which they are conducted. Researchers must bear this in mind when creating experiments, and use controls and other strategies to ensure that bias does not unduly influence results.