In philosophy, rationality is the exercise of reason.^{[citation needed]} It is the manner in which people derive conclusions when considering things deliberately. It refers to the conformity of one's beliefs with one's reasons to believe, or with one's actions with one's reasons for action. However, the term "rationality" tends to be used differently in different disciplines, including specialized discussions of economics, sociology, psychology and political science. A rational decision is one that is not just reasoned, but is also optimal for achieving a goal or solving a problem.

Determining optimality for rational behavior requires a quantifiable formulation of the problem, and the making of several key assumptions. When the goal or problem involves making a decision, rationality factors in how much information is available (e.g. complete or incomplete knowledge). Collectively, the formulation and background assumptions are the model within which rationality applies. Illustrating the relativity of rationality: if one accepts a model in which benefiting oneself is optimal, then rationality is equated with behavior that is self-interested to the point of being selfish; whereas if one accepts a model in which benefiting the group is optimal, then purely selfish behavior is deemed irrational. It is thus meaningless to assert rationality without also specifying the background model assumptions describing how the problem is framed and formulated.

Dan Ariely (born April 29, 1968) is an Israeli American professor of psychology and behavioral economics. He teaches at Duke University and is the founder of The Center for Advanced Hindsight.Ariely's talks on TED have been watched 2.8 million times. He is the author of Predictably Irrational and The Upside of Irrationality, both of which became New York Times best sellers.

Dan Ariely was born in New York while his father was studying for an MBA degree at Columbia University. The family returned to Israel when he was three. He grew up in Ramat Hasharon. In his senior year of high school, he was active in Hanoar Haoved Vehalomed, an Israeli youth movement. While preparing a ktovet esh (fire inscription) for a traditional nighttime ceremony, the flammable materials he was mixing exploded, causing third-degree burns over 70 percent of his body.

Ariely was a physics and mathematics major at Tel Aviv University, but transferred to philosophy and psychology when he found the writing too physically taxing. However, in his last year he dropped philosophy and concentrated solely on psychology, in which he received his B.A. He also holds an M.A. and Ph.D. in cognitive psychology from the University of North Carolina at Chapel Hill. He did a second doctorate in business administration at Duke University at the urging of Nobel economic sciences laureate Daniel Kahneman.

Gerd Gigerenzer (born September 3, 1947, Wallersdorf) is a German psychologist who has studied the use of bounded rationality and heuristics in decision making, especially in medicine. A critic of the work of Daniel Kahneman and Amos Tversky, he argues that heuristics should not lead us to conceive of human thinking as riddled with irrational cognitive biases, but rather to conceive rationality as an adaptive tool that is not identical to the rules of formal logic or the probability calculus.

With Daniel Goldstein he first theorized the recognition heuristic.

He has written several books on the subject of heuristics and decision making, including Simple Heuristics That Make Us Smart (1999), and Bounded Rationality: The Adaptive Toolbox (2001) with Reinhard Selten. His two books for a lay audience, Reckoning with Risk: Learning to Live with Uncertainty (2002, published in the U.S. as Calculated Risks: How to Know When Numbers Deceive You), and Gut Feelings: The Intelligence of the Unconscious (2007), have been translated into 18 languages. "Rationality for Mortals", his most recent book, investigates decisions under limited time and information. He has trained U.S. Federal Judges, German physicians, and top managers in decision making and understanding risks and uncertainties.

Louis Sebastian Theroux (/θəˈruː/ LOO-ee thə-ROO; born 20 May 1970) is an English broadcaster best known for his documentaries in the television series Louis Theroux's Weird Weekends, his BBC2 Specials and When Louis Met.... His career started off in journalism and bears influences of notable writers in his family such as his father, Paul Theroux and brother Marcel Theroux. He currently works with the BBC producing his documentaries and popular TV series.

Theroux is the youngest son of the American travel writer and novelist Paul Theroux (who is of French-Canadian and Italian descent). His mother, Anne Castle, was Paul's first, British, wife. His elder brother is the writer and television presenter Marcel Theroux. He is the cousin of American actor Justin Theroux. He moved to the UK when he was four, and was brought up in London.

Theroux was educated for a couple of years at Allfarthing Primary School then moved to Westminster School (where he was a friend and contemporary of the comedians Adam Buxton and Joe Cornish). Another of his contemporaries was Liberal Democrat politician, Deputy Prime Minister Nick Clegg with whom he travelled to America. He then went to Magdalen College, Oxford where he gained a first class degree in modern history and was noted for his film reviews for the Grapevine magazine.

Joseph James "Joe" Rogan (born August 11, 1967) is an American martial artist, stand-up comedian, actor, writer and color commentator. He is best known for playing Joe Garrelli on the NBC sitcom NewsRadio, commentating for the Ultimate Fighting Championship, hosting the NBC reality show Fear Factor and The Joe Rogan Experience podcast.

Rogan was born in Newark, New Jersey. His paternal grandfather was Irish and the remainder of his ancestry is Italian.

In 1981, at age fourteen, he became a practitioner of Kenpo Karate before transitioning to Taekwondo. He eventually gained a 2nd dan black belt. A four-time state champion in Massachusetts, in 1987 he was the USA Taekwondo U.S. Open Champion. In 1996, he began training in Brazilian Jiu-Jitsu under Jean Jacques Machado, eventually earning his brown belt. In addition, he holds a brown belt in 10th Planet Jiu-Jitsu under Eddie Bravo.

He also practiced and competed in kickboxing.

In 1994, he co-starred on the Fox comedy Hardball as Frank Valente, the young, ego-centric star player on a fictional professional baseball team. From 1995 to 1999, he co-starred on the comedy NewsRadio. He portrayed Joe Garrelli, the electrician at WNYX, a news radio station in New York City. In 2002, he appeared on the episode "A Beautiful Mind" of Just Shoot Me as Chris, Maya Gallo's boyfriend. In 2011, Rogan played his first major character in a movie in the Kevin James movie Zookeeper. He is slated to play himself in an upcoming action-comedy starring Kevin James called Here Comes the Boom, set to be released in the summer of 2012.