One characteristic that all leaders have in common is that they exert influence; thus, a leader is a person who influences the behavior of one or more people by rewarding them, threatening to punish them, using their position of power, knowing more than anyone else, or having a particular personality. One theory of leadership is that people become leaders because of their personalities and the situations in which they find themselves.

The three traditional leadership styles include authoritarian leaders who take charge of a group, democratic leaders who give everyone a chance to participate in decision making, and laissez-faire leaders who do little leading.

Functional leadership occurs when leadership varies with the task of the group and moves from one individual to another as the group finds it suitable. Shared leadership occurs when all group or team members assume both decision-making authority and responsibility for the team's results.

Situational leaders can adopt different leadership styles depending on the situation. Using the telling style, they focus more on the task and less on the group. In the selling style, leaders state the problem and decide what to do, then sell the other group members on the idea. Using the participating style, they state the problem but immediately consult with group members. In the delegating style, they hang back and let members plan and execute the job.

In leading groups, leaders have a number of responsibilities. These include listening, maintaining neutrality and objectivity, establishing procedures, helping the group to progress, seeking diversity, raising questions, focusing on answers, delegating responsibility, encouraging social interaction, and sharing a vision.

Conflict in groups is likely to occur because of perceptual differences, procedure, power, and work distribution. Although substantive conflict in groups can be disruptive, its values in allowing people to grow and change, adapt to new situations, and invent new approaches to problems far outweigh most of the difficulties it creates. One important task of group leaders is to manage conflict. They should determine how serious the conflict is and take one of the following approaches: avoidance, accommodation, competition, collaboration, or compromise.

Because of the popularity of online discussion groups (ODGs), the Internet has become a major player in group discussion. Resolving conflict online requires a great deal of care and deliberation.