口语素材：羊群效应_第2页

　Herd behavior may be called by other names like “mob mentality.” It is sometimes used disparagingly, as the term “mob” typically conjures up an image of a disorganized, aggressive, panicked group of people. A sudden crisis or a demonstration that gets out of order may be subject to humans “herding” into violent clashes with others. More simply a large group of people herding into a single area can produce panic and stampeding, riots, violence, and huge death tolls.

　　The study of group behavior can analyze situations to see where, when, and why they went wrong. Stock market crashes, for example, can be precipitated by mob mentality, as people start to panic in response to fluctuating markets. The evacuation of the Titanic, in which a small fraction of the available lifeboat space was utilized, is another great example of mob mentality, illustrating the need for organized evacuation plans and drills so that people know what to do in an emergency.

　　Benign herding behaviors may be frequent in everyday decisions based on learning from the information of others, as when a person on the street decides which of two restaurants to dine in. Suppose that both look appealing, but both are empty because it is early evening; so at random, this person chooses restaurant A. Soon a couple walks down the same street in search of a place to eat. They see that restaurant A has customers while B is empty, and choose A on the assumption that having customers makes it the better choice. And so on with other passersby into the evening, with restaurant A doing more business that night than B. This phenomenon is also referred as an information cascade.