What would you do if you found yourself in this situation?

Someone ran a social experiment and documented it on hidden cameras.

The experiment starts with a waiting room full of people, a tone is played at random intervals which causes the people to stand up for no reason. A person who is obviously not in on the experiment is then placed in the room. Seeing the people stand up at the tone makes the person stand up as well, even though there is absolutely no reason to.

Watch the full video and try to put yourself in this situation. What would you do? Would you stand up? Start asking questions?