I lived in Cambridge for a while, and that's absolutely preposterous. The city is merely very full of itself and pretentious, and simply does not have an absolute concentration or monopoly on brains.
In fact, most of the "normal" population of Boston and Cambridge rather resent having to play host to the universities.
Harvard and MIT are practically adjacent by West Coast standards
Given that they're less than two miles away from each other, they're practically adjacent by any standards. You can ride the #1 bus for a while or the Red Line just two stops from MIT to Harvard or vice-versa.