"Observer Effect"
The Observer Effect which is also known as The Hawthorne Effect, is a situation where people in studies change their behavior because they are being watched. It can affect all sorts of behaviors such as dietary habits, or hygiene practices because these have considerable opportunity for instantaneous modification. It was proved that individuals being observed would change their behavior and become more productive not because there was any change in any variable such as working conditions or new machinery, but solely because of the attention they were getting. For example, workers might behave differently when managers are around.
So, before you judge someone’s behavior, it’s worth asking if they are changing because you are looking at them, or if their behavior is natural. People are invariably affected by observation. Being watched makes us act differently.
However, we can use the observer effect to our benefit. If we want to change a behavior, finding some way to ensure someone else observes it can be effective. For instance, going to the gym with a friend means they know if we don’t go, making it more likely that we stick with it.