Well, in my perception, we should not only give up seats to
elderly, pregnent women, small kids or parents carrying a toddler
in their arms, but also to conventient of people who need that seat
more than us especially at the front seats.
For example, a middle aged woman may carrying bags of groceries
from the market, we should also be considerate to give up the seat
for her, instead of her moving all the way back for a free
seat.
