To me Elitism is rather simply about looking down on those who do not belong to one's own group.
I think Gustaf hit the nail on the head there. As a teenager I used to go on about 'bloody elitist conservatives', not realising (at the time at least) that this was actually an elitist statement in itself.
Elitism does not involve sheer hatred to the extent that, for example, racism does, but it's another example of human beings trying to distil their insecurities by dismissing those who don't belong to their own social groupings, consequently creating a fake sense of superiority for themselves.
Chances are pretty good that every person on the planet is descended from Egyptian royalty.
Cool.