In the 1920s, a series of experiments were conducted at Hawthorne Works, a Western Electric telephone factory just outside Chicago, to study the effects of lighting on worker productivity. The researchers found that improved lighting increased manufacturing output – but only until the study ended, when productivity reverted to its previous level, even though the new lighting persisted. The researchers concluded that it was the act of being studied, not the lighting, that made workers increase their productivity.
The “Hawthorne effect,” as it is now known, has been well-documented in social science: individuals, typically research subjects, actively change their behavior when they know they are being observed and monitored. The effect goes beyond productivity. It has been found in many different contexts, from improved hand hygiene among health care workers being studied to increased voter turnout when people’s voter preferences are being assessed.