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Tower of Hanoi Problem

  1. Klaus Schmidtke

Published Online: 30 JAN 2010

DOI: 10.1002/9780470479216.corpsy1002

Corsini Encyclopedia of Psychology

Corsini Encyclopedia of Psychology

How to Cite

Schmidtke, K. 2010. Tower of Hanoi Problem. Corsini Encyclopedia of Psychology. 1–2.

Author Information

  1. University Hospital, Freiburg, Germany

Publication History

  1. Published Online: 30 JAN 2010


The Tower of Hanoi is a classical puzzle applied in the psychology of problem solving and skill learning. In the standard wooden version, it consists of three vertical pegs and a variable number of disks, usually three to five, with increasing diameter. The disks have a hole in the middle and are stacked on the left peg in the order of the diameter. The task is to transfer the stack of disks to the right peg with a minimum of moves. Disks are moved from one peg to another, one at a time. Each peg can serve as a temporary target for any disk. Larger disks must not be placed above smaller ones. Performance is measured by the number of moves and/or the time required to complete the task. False moves can also be assessed and classified. The minimum number of moves is 2n − 1, where n is the number of disks (e.g., 31 for the five-disk version). Approximate mean performances on the first attempt are 22 moves in 2 minutes for the four-disk version and 64 moves in 10 minutes for the five-disk version. In aged subjects, mean baseline performance declines.


  • cognitive functioning;
  • diagnostic methods;
  • problem-solving;
  • reasoning;
  • tower of Hanoi