The Tinkerbell effect refers to things that only exist because people believe in them. An example of this is taking paracetamol for malaria and believing yourself to be better because you convinced yourself that it would actually work.
There’s also a reverse Tinkerbell effect. This is when the more you believe in something, the more it’s bound to vanish. An example of this is when you believe that it’s safe to drive to the extent that your illusion of safety causes you to begin to drive with less caution.
Credit: Didyouknowfacts.com
Hmmm, this sounds so farfetched!