Nir Eyal

They change the perception, the illness.

Sickness is in your body, illness is in your brain.

And so placebos are incredibly effective at shaping our experience.

And we can leverage that power of placebo.

If a placebo steroid can actually build muscle,

Maybe it's a good investment to buy a little bit more expensive running shoes if you're trying to take up jogging.

Or maybe, you know, taking that vitamin C is not really going to cure your cold, but it might actually cure some of the symptoms.

It might make you feel better, even if it's a placebo effect.

Okay, so now we're into the power of agency, the third power of belief.

And one of the best demonstrations of the power of agency is what happens when we sap our agency through what we call a nocebo effect.

So we have placebo effect.

Placebo effect comes from the Latin, I will heal.

A nocebo effect is I will hurt.

It's the opposite of the placebo effect.

And to demonstrate this, let me tell you about Mr. A. Mr. A, there was a study where he was anonymized.

Mr. A had a breakup with his girlfriend.

He took it really hard.

And he took a bottle of antidepressants and he swallowed all the pills and he wanted to commit suicide.

The last minute after he swallowed the pills, he decided he wanted to live.

He rushed over to the neighbor's house.