I'm really curious: Do people really not understand how traffic lights function, or do they understand but still choose to press the button multiple times at the crosswalk just for the heck of it?
There are pretty much two ways that crosswalks at traffic lights work, either way they're synched in with the traffic lights on a preset scheduling with minor variations. Sometimes the lights will only go if the button has been pressed (you press the button, then at the next scheduled change it will go green) or some will always go as scheduled regardless of if the button is pressed or not. Either way, pressing the button multiple times does
not make the lights change faster. It's not sending a signal to the lights saying "Quick, stop all the traffic now! Somebody wants to cross!"

And it's certainly not going "Oh they pressed it again, there must be 10 people waiting, we'll let them go now!". Personally, I am familiar with the light changes at intersections I cross regularly, so I know from looking at the traffic patterns exactly when the crosswalk is going to go green. It's not rocket science. Sometimes I walk up and know that it's nearly time, other times I know that I'm going to have a long wait because I can see the traffic going a certain way and know that "my turn" is awhile away.
If I arrive at the lights to cross I will sometimes press the button even if there is somebody else already waiting there, simply because I've been caught out before in situations where *nobody* has pressed the button and we miss the change. However, twice this week I've been at the lights and seen the following happen: Person walks up next to me, presses the button a couple of times. (Fair enough). They stand there. 20 seconds later they reach out and press the button a few more times. Stand there. 30 seconds later again "thwack thwack thwack". Are they just letting out some frustration? Or do they really think it's achieving something? Incidentally, they didn't seem to be in any crazy kind of hurry which might explain it. Once the lights changed I took off at my normal walking pace and left them miles behind. In one case the guy was with a lady and they were chatting casually in between his obsessive button pushing. So it really seems as though they either think they've forgotten and do it again, or they think that somehow the lights have forgotten about them! Is this OTT button pushing just habit, e.g. they're not really thinking about it?