Following on from debates about "ladies first"... I don't think it should be ladies first but the following should apply. AIBU?
It seems to me, if two people are about to walk into the same space at the same time (for instance walking in different directions at a railway station and about to collide) or they are going for the same seat on public transport or coming towards the same door at the same time, the person who would come off worst if they banged into each other should go first. So the bigger, stronger, more able bodied person stands aside, knowing that if they did bang into each other (s)he would hurt the other one.
So I would stand aside for an elderly person, disabled person, someone omln crutches, child up to a certain age, etc. If you are an able bodied adult man you stand aside for most people. If you are a weighlifter you stand aside for almost everyone. If you are an elderly person most people stand aside for you. Most people avoid banging into a toddler or child.
Obviously sometimes it's much of a muchness. In which case you err on the side of politeness. I would suggest in these equal size and strength situations if that person appears to be in a less privileged group you let them through - not because they are physically weaker but because you are luckier. Teens make allowances for adults.
It's just another way of saying you don't barrel through a train station or crowded street knocking smaller and weaker people out of the way! And you don't barrel through assuming that they will stand aside for you because they will be the one hurt.
It wouldn't be an exact science of course but it would be better than the situation of everyone just pushing through.
This used to be called basic manners but has gone entirely out of the window, at least where I live!
AIBU? Or am I just sick of travelling in massive crowds all the time?