Just because a lot of people do it doesn’t mean it’s ‘cultural’. It just means a lot of people are bloody rude. Culture implies that there is some underlying reason for the behaviour that has some benefit to an entire social group - it might be an outdated or ridiculous reason, but there usually is one (see for example the thread on ‘ugly’ dark skin). I’ve never heard anyone articulate a reason for queue-jumping apart from pure selfishness.
I can think of one aspect that’s probably cultural: the difference in personal space. As another poster noted, if you keep real close (in the post office or whatever) it doesn’t happen. Americans, for example, feel uncomfortable with that because their concept of personal space is a lot different. They probably stand way too far back and it’s not obvious - to a Taiwanese person! - that they’re actually in the queue. As a Brit (it’s a crowded country) I find it rarely happens to me because I bunch up with the locals, except (a) when I am at the head of a queue and don’t stand quite close enough to the desk and (b) the queue jumper is wearing blue flipflops.
The airport one is classic. If you tried that at Heathrow you’d have security guards pointing MP7s at your head and frogmarching you off for questioning. They’d assume you were up to something dodgy if you dared to go around the invisible fences.