I am pretty sure this was a C4 show which run a few years ago: groups of people from different nationalities (British, German, Japanese) were told they had won a week long holiday in Turkey. In reality they were being filmed, while actors who had 'infiltrated' the group tempted members to behave in inappropriate/immoral ways. For example, one situation involved an actor jumping a queue to gauge the group's reaction, another involved an actor encouraging other individuals to steal from an unattended bar, yet another involved an old lady who needed help but you had to spend ages helping her, etc. The programme considered how different nationalities reacted to these situations.
I remember seeing it at the time, but can't find any reference to it now (have trawled loads of sites and tried Googling it). I am writing a paper on reality TV shows and wanted to reference it, so any information would be greatly appreciated.