Overjustification effect is the result of bribing someone to do what they are already doing. This makes it seem like a task rather than something to do out of enjoyment. Because it seems controlled, it is less appealing to the person doing the task, when originally they would be doing it anyway.
I always played volleyball for fun. Once I was in college and on scholarship, it became more of a job and although I love the sport I think I may have enjoyed it less. This is an example of overjustification effect.
I remember going to the Food and Care coalition and volunteeering my time. When they offered me a job I felt silly because the pay wasn’t where I wanted it to be.