The Hawthorne Effect: When Observation Changes Reality

Many of us have noticed how simply being observed by others can affect our choices and performance. When we realize we’re being watched, we may draw in more self-awareness and evaluate our behaviors or responses further. Maybe some extra motivation to work harder comes in when your coworker is working next to you. Or maybe in a group fitness class, you’re more motivated to push for an extra rep than you would when working out at home. We often strive to perform better when we know we’re being observed or evaluated to present ourselves in a more favorable light. This familiar concept is known as social facilitation.

While social facilitation describes improved performance due to the presence of others, the Hawthorne Effect refers specifically to behavior changes among study participants who know they are being observed in a research setting. This often results in temporary improvements in their behavior and may not be a true reflection of their routine performance in daily life.

The term “Hawthorne Effect” originated from a study at the Hawthorne Works electrical factory in Chicago, where researchers observed a temporary boost in worker productivity—not due to lighting changes as initially believed, but because employees knew they were being watched. As soon as the workers became aware that they were being watched by the researchers and that their performance was being evaluated for the study, they began to temporarily increase their productivity levels in order to appear more efficient. The effects of their improved efficiency were not long-lasting and they would soon revert back to their standard working practices post evaluation. This phenomenon was named the Hawthorne Effect.

A striking example of this can be seen in hospital settings. In a study of hand washing compliance among medical staff, researchers found that there was a 55% increase in compliance when staff had the knowledge that they were being observed. The study recorded a total of five hand hygiene events per hour during the observation period and only two hand hygiene events per hour without observation. The researchers found that 61% of the variability among participants was due to the absence or presence of observation which could be explained by the Hawthorne Effect.

“In research studies, this temporary increase in performance due to observation can commonly affect behaviors that allow for instant modification such as dietary choice or hygiene practices.”

Structured research settings have the ability to greatly influence the participants behavior in a way that goes beyond standard controlled variables. Furthermore, when participants are made aware that they are contributing to a study, they may be more motivated to confirm the researcher’s hypothesis, whether consciously or unconsciously. In a placebo-controlled trial of Ginkgo biloba for treating mild to moderate dementia, participants who were dementia patients had either minimal follow up or intensive follow up. They found that the participants who received the intensive follow up had better cognitive functioning outcomes than those who only received minimal follow up during the placebo controlled clinical trial. These findings suggest that when study participants become aware that their behavior is being evaluated, they may alter it which results in their responses no longer reflecting their authentic performance or responses.

“These findings suggest that when study participants become aware that their behavior is being evaluated, they may alter it which results in their responses no longer reflecting their authentic performance or responses.”

The participants’ awareness that they are being observed may begin to alter their routine habits to make their behaviors appear more socially desirable. With this in mind, it is important for scientists to be aware of a potential bias like the Hawthorne Effect when conducting research and interpreting findings in social science, especially when it comes to easily modifiable practices. A systematic review of 19 studies examining participants who were aware they were being observed found considerable variation in the impact of the Hawthorne Effect. While there was not a clear overall summary of the effect, the researchers noted that in some circumstances, simply participating in a study does appear to influence behavior.

Studies examining how diet impacts the gut microbiome must account for the Hawthorne Effect, as participants may temporarily modify their eating habits simply because they know they’re being observed. Additionally, depending on how the study is set up, participants may feel pressure to adhere more strictly to dietary guidelines. An increase in self-awareness could lead to more ideal reporting as opposed to their real-life dietary habits. This makes it challenging to generalize findings to everyday practices in an individual’s daily life.

“An increase in self-awareness could lead to more ideal reporting as opposed to their real-life dietary habits.”

In order to prevent the Hawthorne Effect, researchers may want to use hidden observation methods to avoid the participants feeling like they are being watched. However, even just their awareness that they are in a study is believed to have the ability to cause the Hawthorne Effect. Since all participants must give informed consent, they will always know that they’re a part of a study, meaning the Hawthorne Effect is likely present to some degree in any studies that evaluate human behavior.

Though the Hawthorne Effect can’t be entirely eliminated, recognizing its presence helps researchers design more accurate and reliable studies. When research is gathered over an extended period of time, this allows for any initial temporary improvements in behavior to fade and allows researchers a better chance to observe participants’ real-life behavior. While the Hawthorne Effect may not be totally avoidable, understanding the presence of this potential bias allows researchers to design studies that reduce the impact of observation allowing them to gather and interpret results with greater accuracy.