Exactly, all of this. On my way home, people do the same during a transition. They don't merge. Instead, they SPEED UP and go all the way to the front, bypassing everyone until they hit a dead end. They then have to STOP, otherwise they will be forced to exit the freeway. Now they have to battle to have everyone let them over. They cause a massive traffic jam every day which delays countless thousands of people, all because they gave in to their selfish urge to fuck over their neighbor and move ahead.
People have a very primitive impulse to cut ahead, or screw someone over, even if the outcome is worse for themselves. Its just amazing to see it in action. No thought involved at all. These are instinctive, hasty moves intended to fuck people over which ends up fucking everyone.