It's not just cameras in the home. Each household is filmed over one day so the crew have to bring the videos for them to watch, they have to change clothes and snacks between takes, they are sometimes fed quips when they have nothing to say and of course there are retakes.
I've haven't watched the show, but seen a couple of trailers. I never believed the things they say were genuine and spontaneous. It looks like a set-up. Thanks for confirming, hc4361.