In general, I will give up my seat to a pregnant woman, not because she is a woman, but because she is much harder to stand than I am. By the way, for the same reason I would offer my place to an old man or a disabled man, and not to a fifty-year-old healthy aunt. I will help the girl to bring home the shopping, but not because the man has to help the woman, but because she is hard and I would help a friend, or parents. No one should be late. and so on.
And all unwritten rules, such as those that say who should enter the elevator first, or in the door, who should go to the right and who to the left and the like are absolutely useless and can be ignored.