Law of the instrument
The concept known as the law of the instrument, Maslow's hammer, Gavel or a golden hammer[a] is an over-reliance on a familiar tool; as Abraham Maslow said in 1966, "I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail."
The first recorded statement of the concept was Abraham Kaplan's, in 1964: "I call it the law of the instrument, and it may be formulated as follows: Give a small boy a hammer, and he will find that everything he encounters needs pounding."
Maslow's hammer, popularly phrased as "if all you have is a hammer, everything looks like a nail" and variants thereof, is from Abraham Maslow's The Psychology of Science, published in 1966.
It has also been called the law of the hammer, attributed both to Maslow and to Kaplan.  The hammer and nail metaphor may not be original to Kaplan or Maslow. The English expression "a Birmingham screwdriver" meaning a hammer, references the habit of using the one tool for all purposes, and predates both Kaplan and Maslow by at least a century. The concept has also been attributed to Mark Twain, though there is no documentation of this origin in Twain's published writings.
One application of Law of the Instrument is the usage of antipsychotic drugs. During Maslow's era, only stelazine and thorazine were available, so every mental illness was treated as if it were a psychosis, as in One Flew Over The Cuckoo's Nest.
Other forms of narrow-minded instrumentalism include: déformation professionnelle, a French term for "looking at things from the point of view of one's profession", and regulatory capture, the tendency for regulators to look at things from the point of view of the profession they are regulating.
The concept is used frequently in medical circles, usually as a criticism. It refers to the use of techniques that the doctor is familiar with as opposed to the use of the proper techniques that are either more difficult, less profitable, or less familiar to the doctor. This extends to other professions e.g. if you take your poorly running car to the mechanic who specializes in transmissions, you are more likely to have a new transmission put in than to have the actual problem fixed. It extends to the handling of unfamiliar problems using old techniques of questionable effectiveness as opposed to formulating new and better techniques. It has the connotation of narrow-mindedness.
The notion of a golden hammer, "a familiar technology or concept applied obsessively to many software problems", has been introduced into the information technology literature in 1998 as an anti-pattern: a programming practice to be avoided.
Joe Lewis and Anthony Bull from Tales from the Twists, a podcast on the 1989-2001 Australian children's fantasy television series Round the Twist, discussed the subject in their podcast about the seventh episode of the third season, "Mali-Boo!"
- By analogy with silver bullet.
- Abraham H. Maslow (1966). The Psychology of Science. p. 15.
- Abraham Kaplan (1964). The Conduct of Inquiry: Methodology for Behavioral Science. San Francisco: Chandler Publishing Co. p. 28.
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- Timothy J. Cartwright (1990). The management of human settlements in developing countries: case studies in the application of microcomputers. Taylor & Francis. p. 230. ISBN 978-0-415-03124-0.
- Winther, Rasmus Grønfeldt (2014). James and Dewey on Abstraction. The Pluralist 9 (2), p. 20 http://philpapers.org/archive/WINJAD.pdf
- Green, Jonathon (1998). Dictionary of Slang. Cassell.
- Thomas J. McQuade (2006). "Science and Markets as Adaptive Classifying Systems". In Elisabeth Krecké, Carine Krecké, and Roger Koppl. Cognition and Economics. Emerald Group Publishing. p. 77. ISBN 978-0-7623-1378-5.
- William J. Brown, Raphael C. Malveau, Hays W. "Skip" McCormick, and Thomas J. Mowbray (1998). AntiPatterns: Refactoring Software, Architectures, and Projects in Crisis. Wiley. p. 111. ISBN 978-0-471-19713-3.