Trading Spouses/Wife Swap

I just don't understand how these people can put themselves out there on tv like that. I DO realize it's either scripted or heavily edited since it IS reality tv, but exactly HOW MUCH is scripted or edited? Are these people really like this? and if so, why oh why do they go on these shows knowing the conflict that will arise? I suppose the money is a nice insentive but the other family gets to pick how they spend it, so it's really a gamble.