According to research by Milgram, we are influenced by the mere presence of others. In the research that he conducted, people conformed to shocking people at a severe level simply because they were told that the experiment must go on. In actuality no one was really shocked but a confederate played along with the experiment to test conformity. Listed below are several sites that deal with many aspects of conformity and social pressure. There are two types of leadership instrumental and expressive.
Instrumental leadership is the type of leadership that focuses on getting things done.
They tend to have secondary relationships with members of their group, and tend to concentrate on performance. Expressive leadership focuses on the well-being of the group. This type of leader has a primary relationship with members of the group and offers sympathy. There are also several leadership styles. Leadership and authority play a role in social groups in several different ways.