Abstract:
It was a typical winter morning in New York. Suddenly a man stopped and started to stare at the sky. People were passing by and almost nobody paid attention to this man. Next morning a group of four people started staring at the sky and ... almost everybody walking by joined them. After several minutes the crowd blocked the street. What had happened? Social Validation worked. The fundamental way that we decide what to do in a situation is to look to what others are doing. We like to think about ourselves as individuals. Indeed, we are individuals but in many situations we behave like particles, which have no feelings and no free will. Not too many people are convinced by this statement but a number of experiments conducted by social psychologists confirm that. From a physicist's point of view the behavior of individuals and the interactions between them constitute a microscopic level of a social system. The question is if the laws on the microscopic scale of a social system can explain phenomena on the macroscopic scale, phenomena that sociologists deal with. In this lecture we go back to the beginning of the 20th century, when physicists were asking a similar question in physics: Can interactions on the microscopic scale explain such a global behavior as a phase transition. The simple Lenz-Ising model showed that it was possible. However, physicists had to wait for this answer for many years. Today we ask the question in social sciences - is there any path between social psychology and sociology? And we still wait for the answer ...