Old money vs new money, Harvard vs others, Boston Irish vs Others. The cultural divides are subtle. They are like glass ceiling. You will realize how big a deal it is when you enter to their priorities. For getting most of the jobs, no one could care less. Try housing - You will not get housing in certain areas unless you project a certain class.
Sati existed in upper castes too. In the Kennedy family maintaining a certain social style is far more important. JKF sister went through lobotomy and suffered entire life social pressure due to mental health problems https://en.wikipedia.org/wiki/Rosemary_Kennedy