The social experiment mentioned in the beginning (Spoiler)
The movie starts with a voiceover of Ethan stating there had been an experiment in England where people were told hired strangers would be interfering in their lives, later recounting they were seriously affected by these strangers, but in fact
"nothing was done to them and the only thing altered was their perception".
Does anybody know if this experiment was actually done in real life?
It may be just made up by the writers, it's a clever opening considering the movie's ending, but ... just curious if it's based on an actual experiment.