Leadership has been described as "a process of social influence in which a person can enlist the aid and support of others in the accomplishment of a common task". For example, some understand a leader simply as somebody whom people follow, or as somebody who guides or directs others,[citation needed] while others define leadership as "organizing a group of people to achieve a common goal".[citation needed]Studies of leadership have produced theories involving traits, situational interaction, function, behavior, power, vision and values, charisma, and intelligence, among others.