In most elevators, at least in any built or installed since the early nineties, the door-close button doesn’t work. It is there mainly to make you think it works. (It does work if, say, a fireman needs to take control. But you need a key, and a fire, to do that.) Once you know this, it can be illuminating to watch people compulsively press the door-close button. That the door eventually closes reinforces their belief in the button’s power. It’s a little like prayer.
The article is a surprisingly interesting essay on elevators. I particularly liked the bit about "smart elevators", in which you input your floor at a central control panel, and it tells you which elevator to take. Consequently, the elevators themselves have no control panel, which apparently makes people feel like they've been kidnapped by a Bond villain.