Hofstadter's law

From Wikipedia, the free encyclopedia

Hofstadter's law is a self-referential adage, coined by Douglas Hofstadter in his book Gödel, Escher, Bach: An Eternal Golden Braid (1979) to describe the widely experienced difficulty of accurately estimating the time it will take to complete tasks of substantial complexity:[1][2]

Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law.[2]

The law is often cited by programmers in discussions of techniques to improve productivity, such as The Mythical Man-Month or extreme programming.[3]


In 1979, Hofstadter introduced the law in connection with a discussion of chess-playing computers, which at the time were continually being beaten by top-level human players, despite outpacing humans in depth of analysis. Hofstadter wrote:

In the early days of computer chess, people used to estimate that it would be ten years until a computer (or program) was world champion. But after ten years had passed, it seemed that the day a computer would become world champion was still more than ten years away... This is just one more piece of evidence for the rather recursive Hofstadter's Law.[4][5][6][7]

In 1997, the chess computer Deep Blue became the first to beat a human champion by defeating Garry Kasparov.[8]

See also[edit]


  1. ^ Waters, Donald J.; Commission on Preservation and Access (1992). Electronic technologies and preservation. Commission on Preservation and Access. ISBN 9781887334167. Retrieved 2011-06-08.
  2. ^ a b Gödel, Escher, Bach: An Eternal Golden Braid. 20th anniversary ed., 1999, p. 152. ISBN 0-465-02656-7.
  3. ^ David M. Goldschmidt (October 3, 1983). "The trials and tribulations of a cottage industrialist". InfoWorld. 5 (40). InfoWorld Media Group, Inc.: 16. Retrieved 2011-06-08.
  4. ^ Gödel, Escher, Bach: An Eternal Golden Braid, Basic Books 1979, Vintage Books Edition, 1980, p. 152.
  5. ^ Gödel, Escher, Bach: An Eternal Golden Braid. 20th anniversary ed., 1999, p. 152. ISBN 0-465-02656-7
  6. ^ Rawson, Hugh (2002). Unwritten Laws: The Unofficial Rules of Life as Handed Down by Murphy and Other Sages. Book Sales. p. 115. ISBN 9780785815433. Retrieved 2011-06-08.
  7. ^ "Hofstadter's Law". The Unwritten Laws of Life. 2008. Archived from the original on 2011-08-26.
  8. ^ Greenemeier, Larry (June 2, 2017). "20 Years after Deep Blue: How AI Has Advanced Since Conquering Chess". Scientific American. Retrieved January 3, 2023.