Domino Effects
http://www.economist.com/blogs/democracyinamerica/2011/10/mass-movements
People are like dominos. An individual is greatly affected by the actions of others. When one person makes an action, people start falling into taking the same action and whole domino effect occurs. In economics, this “domino effect” is the information cascade. Information cascade exists in many different fields. As the article describes this happens very frequently in stock exchanges. The ‘signal’ that the stockholders receive is the rising or falling price. When the price is rising, more and more people start buying the price thus raising the price even more and when the price is decreasing, people sell their stocks, lowering the price even more.
The article even uses the example of riots in companies. When one person starts up a riot, more and more people follow. People are in a way justifying their actions by thinking if many people take an action, that action is justifiable no matter what the authority tells them. This is somewhat part of crowd psychology. People have lots of things going on in their mind and an action of someone else just triggers one of the many thoughts in the mind. Even if someone did not have a particular action in mind, seeing someone else take that action makes that individual want to take the same action. It is very much psychological.