Did you know about the "Hawthorne effect"?

If you want a detailed description on Wikipedia, here it is (https://en.wikipedia.org/wiki/Hawthorne_effect), otherwise I’ll explain it myself, based on my own research or both:

Subjects (read on) typically modify their behavior when they recognize that they are part of an experiment. This is known as the Hawthorne effect, named after the place where this result was first encountered, the Western Electric’s Hawthorne Works. A basic study to determine how the level of light in their building affected the productivity of laborers revealed that the amount of luminosity made no difference in the employees’ productivity. The workers increased output whenever the light was manipulated, whether from low to high or vice versa. In fact, a change in productivity occurred when any variable was manipulated, which made the researchers postulate that the staff altered their behavior simply becaise they were aware that they were under observation.
Some subjects have this predisposition, all researchers can do is attempt to factor this effect into the research design.