The word originally comes from a word for midwesterners known as "Jan Kaas" or dutch for John Cheese, as many of them made cheese such as in Wisconsin. It gradually became a word for any northerner.
Someone who pretends to be left-leaning and to like art but actually minimizes the danger of
everything in an institutional fashion, perhaps from Catholic/Jehovas Witness/
Episcopalian influence, but still pops into a sex-club on Saturday regardless of the institutional religious background he or she may come from. The yankee may feel like he won the
American civil war even though he is only a second generation Italian/Jew/Irishman. Their rent tends to be higher than other areas.