People don’t like being told what to do. There’s even a word for it: reactance.

“Psychological reactance is a negative emotional state that we feel when we’re not in control of our behavior,” says Jonah Berger, author of The Catalyst: How to Change Anyone’s Mind, and a marketing professor at The Wharton School of the University of Pennsylvania. “We have a drive for freedom and autonomy. Anytime we feel like someone else is trying to persuade us, or shape our behavior or actions or attitudes, we essentially put up an anti-persuasion radar. You can almost think about it like an anti-missile defense system.”

This can be useful in many ways. It’s the reason that advertisements don’t empty our bank accounts, and why we don’t (usually) fall for scams.