We All Affect Each Other

Once we had the social media analytic class, professor told us that she would ask a question in the class and wanted us to answer 'C is the answer' to cooperate with her when few students hadn't arrived at the classroom. The question was very simple which is to compare the length of three lines to the reference line and find the same one as the reference. Although it is obviously that line B had the same length, we all said that C was the correct answer as professor told us. Then professor asked the students who reached classroom later about their answer. They looked confused and didn't know what's wrong with all of us. Then some of them started to change their mind to meet our answer while others still thought B is the most likely line but doubted about themselves's perception. This is a very interesting quiz to show the phenomenon that people all affect each other. People are scared to be weird, so popular opinions influence our own cognitions seriously. Popular trends vary from year to year, people pursue them because they come from famous experts in each fields. It is safe and easy to be same. There is a common sense that the more people claim the higher probability to be truth. We have to hold similar cognition to insure getting along with others well. It seems that the simplest way to adapt to society is being similar to  main stream.