Even if it's not strictly scripted, the participants are surely cast for type. Producers handpick them to make sure they will fight, or break down, or otherwise make a scene that will constitute great television.
Same principle as on Big Brother but because there's less time involved, they have to start the conflicts earlier.
The contestants were also probably "encouraged" to accentuate their stories to appear more interesting on camera, since it is a TV show after all. I think it's no more fake than say Big Brother was fake, or The Bachelor is fake.