Why do people in elevators push ons fast and more than one time knowing its not going to make it faster?

Paladin's pretty close, actually. The feeling that they could be wasting time (i.e. doing nothing, waitng for the lift to arrive) makes them feel, well, that they're wasting time, so they keep pressing it to ure themselves that being late can have nothing to do with them since they haven't stopped doing anything.