I just watched an episode of House where the storyline followed a patient who involuntary spoke everything he thought.
Season five, The Social Contract if you're interested.
We build social courtesies for a reason, people don't want to hear that you think they look fat. They don't want to hear that you've been thinking about sleeping with them.
I pride myself on my honesty and bluntness - but even I know the limits and the benefits of keeping certain things locked away.
Not to mention, I can't imagine those you know will appreciate being an 'experiment' - you toying with their emotions just for your own amusement.
Additionally, don't go out of your social circle for the week. Guarantee you'll end in a fight or arrested otherwise.