The room I work in is accessed through a pair of double doors.

Whenever I am approaching the doors from one direction and someone else is approaching it from the other, what almost invariably happens is that whoever gets there first opens one of the doors, then either stops and holds it for the other person to go through, or holds it for the other person after they've gone through. Always, there is a politeness-door-holding moment, and someone stops and waits until the other person has gone through whichever door was opened. This is exactly identical to what would have happened if there had only been a single door.

But there isn't only a single door. These are double doors, the whole point of which (you would think) is that the opening is wide enough for two people to go through simultaneously without getting in each other's way.

What's with this? Holding the door is utterly instinctive in this circumstance – once or twice I've deliberately ignored the other person and opened the other door so we can both go through without either of us having to stop and wait, and it felt horribly unnatural and rude.

I suppose it's vaguely possible that the effort of pulling a heavy door open might be deemed worse than the delay of waiting for someone else to go through, so that having both people go through the same door works out more efficient; but in that case, why build the double doors in the first place if they were never going to be used?

It's weird. Someone has wasted a lot of time and effort, but I can't work out whether it's the people who built the double doors or the people who keep stopping and waiting for each other when it's unnecessary.