The vast majority of the time, the door-close button on elevators doesn’t do anything. This is the case for the elevators in our office building.
When they’re in the lobby, and someone pushes a floor button, the elevators wait for an extra 5 seconds before closing the doors. This is an optimization to accumulate additional passengers — when lots of people are coming in and out of the lobby all the time, you don’t want elevators going up with just one person in them.
Inevitably, people start getting impatient and hitting the door-close button after about 4 seconds. It doesn’t do anything, but the doors close a second or two later regardless, so people think they’ve affected the outcome, and they push the door-close button again the next time. If they push the button too soon, and the elevator waits a few more seconds before closing the doors, the people assume that it’s just being slow today or they didn’t hit the button hard enough.
They never consider the possibility that their action is not related to the result.
This is why superstition works. Animals learn it, too. “If I perform this action, I get this result.” It takes a more advanced or analytical mind to consider performing a test: “If I take no action, will I get this result anyway?”
I secretly think less of door-close people in the elevator.