This piece refers to the experiment on conformity covered in the last part of chapter 2 in The Wisdom of Crowds. This is different to the "social proof" of the street corner experiment. Here it was found that people will conform to the accepted decision because they don't want to stand out and simply want to go along with the crowd. This isn't a bad way to spend five minutes (even if the clip looks about 30 years old!)
Another take on it is available here.