How to find out whether a reality show is scripted

Check the credits for any job called 'Story Editor' or similar - a friend of mine is one for many UK Reality TV shows and it's a pretty good indication that either the words/ideas that are on screen are planned or that the real goings-on have been crafted to tell a planned narrative.

Every single "Reality TV" show is scripted to some degree. There is just no way to effectively follow someone around 24/7 and hope to capture some drama somewhere, so in order to be cost-effective that drama must be created via scripts. Some, like Pawn Stars, are obvious because some of the "actors" are horrible at acting.

The only potential exception to the rule would be Big Brother, because they're in a controlled environment with cameras 24/7. They would have very little time (if any) to script anything, because even in the hours it's not on TV there are "Big Brother cams" you can view online.

Note: This answer is for US shows only, as I have no knowledge of shows in other countries.

David Rupel explains:

Just like scripted television, writing and producing go hand in hand. The majority of my reality credits are for producing, not writing, but I'm always using my skills as a storyteller.

For example, when Monica and Chandler slept together on Friends, it was referred to as a "plot twist." When the tribes didn't merge as expected on this season's Survivor, it's simply known as a "twist." The subtle language difference implies that somehow the twists in reality magically "happen on their own." Nothing could be further from the truth. There is every bit as much thought, debate, and imagination behind every twist you see on reality–both big and small. Just like making Joey and Chandler roommates was a deliberate choice the writers made on Friends; when I produced Temptation Island, I chose room assignments based on how I thought people would affect each other.

Similarly, every time I select a location, develop a game, find a cast, look for appropriate music, it's always based on story. How will this affect the cast? Is it setting the right mood? Will it help the audience understand what's going on? All the same questions I ask myself when I write a script.