Culturally, I've noticed something interesting while riding this train for years, and that is how different cultures treat their elders. Now you have to understand that this comes from a lot of people watching and observation. This is not simply a random opinion.
The order in which the most respect is shown to least is:
1.) Asians, specifically Japanese. Not only offering their seats, but have seen more than one younger person seek out seating for an older man or woman.
2.) African-american. Again, quick to stand and offer seating. It's been very heartening to see such respect to elders. Make and female both offer seating.
3.) White people. Not as frequently but it happens a lot. It's mostly men getting up. The most rare being young girls giving their seats to older women.
4.) Latinos. A whole lot of "go fuck yourself" mentality. Big difference. Mostly from the younger girls. In fact, I've seen young girls race old Latino women to a seat to take it from them. It's sickening.
Again, this is years of observation, so I'm just saying what I have seen. Have I seen a Mexican guy offer his seat? Yep! Have I seen a Asian hipster actively ignore an older lady? Absolutely. But those are aberrations.
Weird, eh?