here in buenos aires, tradition dictates that the bus seat is given up to people who have trouble walking or staying up, including pregnant women, injured people, and people with small children (plus whoever else you might feel like giving the seat to). of course, there are seats that are reserved for such people (mandated by law), and if you sit in one of those, you damn well better give it up when necessary. don't wanna give your seat, sit on the normal ones