The buses are often very crowded and if you don't have a place to sit you are left standing. You will, as elsewhere, offer your seat to elders, pregnant women and such. Also, ofcourse, to beautiful girls if you're a young man full of hormones or an elder man who also likes beautiful young women. There's a lot of sympathy for the beautiful young women in Brazil and men of all ages help them never getting exhausted.
Often seen, which struck me as sympathetic and different, is the habit of seated persons carrying on their laps the loads of standing persons. This gives a relief to the standing person, and also offers him/her a better balance, the buses not being a stable invironment having to break and go, do fast turns (yes, I think it must be a law for the bus drivers to really push the limits on speed at all times), and also when exposed to the innumerable speed bumps, which seams to be Brazilians solution to all trafic problems. It is not uncommon to have speed bumps every 100 meters, even in areas which are mostly for transit.
The charger is seated in the middle of the bus. Here he controls who goes on and off, and that no one gets on at the exit door (which would leave this person not paying). He also controls and gives a sign to the driver when everyone that intended has left the bus and the driver might close the door and take off again.
The charger is the one that has most contact with the public. On the photo above helping a woman to get off at the right stop.
