Jackie-IMO-typified the air headed socialities of the 50`s (today too). Bored, superficial and a bit slow. She knew what Kennedy was and married anyway. She was just as ambitious and shallow as JFK.
Thing is, that she had to marry well, since back then women did as well as their husbands, good or bad, it depended on the man.
Air headed-ness is NOT the bailiwick of socialites. It is part and parcel of one's I.Q., personality and upbringing. That is, it's part of human nature.
God made us, so He bequeathed us that part of ourselves. Perhaps it was His sense of humor. He DID invent the sense of humor.