The Hawthorne Effect is a phenomenon in which individuals modify their behavior in response to being observed. It is named after the Hawthorne Works, a factory in Illinois, where a series of experiments were conducted in the 1920s and 1930s to measure the effects of changes in working conditions on
From Wikipedia
The Hawthorne effect is a type of behavioral reactivity in which individuals modify an aspect of their behavior in response to their awareness of being observed. The effect was discovered in the context of research conducted at the Hawthorne Western Electric plant; however, some scholars think the descriptions are fictitious.