Leadership has been described as “a process of social influence in which one person can enlist the aid and support of others in the accomplishment of a common task". Other in-depth definitions of leadership have also emerged.

Leadership is "organizing a group of people to achieve a common goal". The leader may or may not have any formal authority. Students of leadership have produced theories involving traits, situational interaction, function, behavior, power, vision and values,charisma, and intelligence, among others. Somebody whom people follow: somebody who guides or directs others.

The search for the characteristics or traits of leaders has been ongoing for centuries. History's greatest philosophical writings from Plato's Republic to Plutarch's Lives have explored the question "What qualities distinguish an individual as a leader?" Underlying this search was the early recognition of the importance of leadership and the assumption that leadership is rooted in the characteristics that certain individuals possess. This idea that leadership is based on individual attributes is known as the "trait theory of leadership".

Simon O. Sinek (born October 9, 1973) is an author and best known for developing "The Golden Circle" and popularizing a concept of human motivation. He joined the RAND Corporation in 2010 as an adjunct staff member, where he advises on matters of military innovation and planning. His first TEDx Talk on "How Great Leaders Inspire Action" is the 19th most viewed video on TED.com. His book on the same subject, "Start With Why: How Great Leaders Inspire Everyone to Take Action," (2009) delves into a naturally occurring pattern, grounded in the biology of human decision-making, that explains why we are inspired by some people, leaders, messages and organizations over others.

He writes for The New York Times, Wall Street Journal, The Washington Post, Houston Chronicle, FastCompany, CMO Magazine, NPR and BusinessWeek, and is a regular contributor to The Huffington Post, BrandWeek, IncBizNet.

Sinek was born in Wimbledon, England; at a young age he moved to Johannesburg, South Africa, then to London, then to Hong Kong, before settling in New Jersey. He earned a BA degree in cultural anthropology from Brandeis University; he attended City University in London with the intention of becoming a barrister, but left law school to go into advertising.

Leonard Davids (March 19, 1926 – February 10, 2002), better known as Bob Davids or L. Robert Davids, was a longtime baseball researcher and writer and founding member of the Society for American Baseball Research (SABR). He wrote numerous freelance articles on baseball for the Sporting News between 1951 and 1965. When TSN cut its baseball coverage, Davids began his own short-lived baseball publication, Baseball Briefs. He contributed baseball fact boxes to several newspapers, including the Washington Post and Chicago Sun-Times. In 1971, Davids identified approximately 35 others with similar interests in baseball statistics and history – he called them “stathistorians” – and invited them to meet in Coopertown, New York at the Baseball Hall of Fame. Sixteen attended the meeting, and agreed to the formation SABR. Davids was elected the group’s first president, an office he held on two other occasions. He also served two 5-year terms on SABR’s board of directors, and was actively involved in producing many of the organization’s early publications. Davids was also active in SABR’s first regional chapter, which was named in his honor.

Seth Godin (born July 10, 1960) is an American entrepreneur, author and public speaker. Godin popularized the topic of permission marketing.

Born in Mount Vernon, New York, Seth Godin graduated from Tufts University in 1979 with a degree in computer science and philosophy. Godin earned his MBA from the Stanford Graduate School of Business. From 1983 to 1986, he worked as a brand manager at Spinnaker Software. For a time Godin commuted every week between California and Boston both to do his new job and to complete his MBA..

After leaving Spinnaker Software in 1986, Godin used $20,000 in savings to found Seth Godin Productions, primarily a book packaging business, out of a studio apartment in New York City. It was in the same offices that Godin met Mark Hurst and founded Yoyodyne. After a few years Godin sold the book packaging business to his employees and focused his efforts on Yoyodyne, one of the first online marketing companies.^{[citation needed]} It was with Yoyodyne that Godin came up with the concept of permission marketing.^{[citation needed]} For a period of time, Godin served as a columnist for Fast Company^{[citation needed]}

Anthony "Tony" Robbins (born February 29, 1960) is an American self-help author and motivational speaker. He became well known through his infomercials and self-help books, Unlimited Power: The New Science Of Personal Achievement and Awaken The Giant Within. Robbins writes about subjects such as health and energy, overcoming fears, persuasive communication, and enhancing relationships. Robbins began his career learning from many different motivational speakers, and promoted seminars for his personal mentor, Jim Rohn. He is deeply influenced by neuro-linguistic programming and a variety of philosophies.

Robbins's work has been featured in major media including Time, Newsweek, Fortune, Forbes, Life, GQ, Vanity Fair, Business Week, Tycoon and Success magazines, the CBS Evening News, NBC News, ABC's Prime Time Live, Fox News, CNN and A&E as well as newspapers, radio programs, and Internet media worldwide. Robbins has been mentioned or featured in 15 major motion pictures, including a cameo role a romantic comedy film Shallow Hal, starring Gwyneth Paltrow, Jack Black, and Jason Alexander. In 2007, he was named to Forbes magazine's "Celebrity 100" list.