[paganel]

The Marshmallow Test looks kind of classist, or even racist (not sure if "racist" is the right word for it, maybe "orientalist" would be better).

Yes, if you live in Stanford or in a country that has an institution like Stanford then most probably "passing" the marshmallow test means waiting for a longer period in order to get twice the reward, but I dare say not a lot of countries/societies afforded that luxury until not that long ago (many of them still don't), in their case waiting for longer in order to get twice the reward might mean that you'll be dead by then, or evicted, or you had to escape the communists/the criminal right-wingers/the islamist beheaders/what have you.