How real do you think reality TV is?

We have programs like Real Housewives of [fill in the blank] that show some of the most self centered, bitchy behavior imaginable. How real is all this? I mean the show has a producer and director. They want as much drama as is humanly possible and must certainly ask the participants to generate it in spades.

The actors and actresses have to be completely aware they are on national TV acting out in these ways. How likely would people be to show their worst side when there is a producer, director, camera men, lighting crew, make-up assistants and grips following them everywhere they go—unless the producer scripts all the drama and tells them how to pick each fight?