One of the earliest demonstrations of the overjustification was seen in an experiment conducted by Edward Deci in 1971. Edward Deci is a professor of psychology and a pioneer of behavioral science.

What is overjustification effect in psychology?

The overjustification effect is a phenomenon in which being rewarded for doing something actually diminishes intrinsic motivation to perform that action. ... In psychology, this is known as the overjustification effect and it can have a serious impact on your motivations and behaviors.

What is undermining effect?

Deci highlighted the so-called undermining effect: if you provide incentives for someone to carry out an activity they already enjoy, it undermines their original reason for doing it.