Having said that there was a piece on the radio the other day about these shows, and there was a remark which struck me - the reporter suggested that these programmes are social experiments masquerading as mass entertainment, whereas the thing that for me distinguishes British efforts in this arena is that they are exactly the opposite: there is always some affectation of worthiness, such as the Big Brother psychologist.
Of course, later tha same day I heard the chairman of the FCC ask rhetorically (and apparently without irony) if there was any other broadcast system in the world that the listener would choose to replace the US one with.