The Candle Problem
Encyclopedia
The candle problem or candle task, also known as Duncker's candle problem, is a cognitive
performance test, measuring the influence of functional fixedness
on a participant's problem solving
capabilities. The test was created by Gestalt psychologist
Karl Duncker
and published posthumously in 1945. Duncker originally presented this test in his thesis on problem solving tasks at Clark University
.
on a wall (a cork board) in a way so the candle wax won't drip onto the table below. To do so, one may only use the following along with the candle:
The solution is to empty the box of thumbtacks, put the candle into the box, use the thumbtacks to nail the box (with the candle in it) to the wall, and light the candle with the match. The concept of functional fixedness predicts that the participant will only see the box as a device to hold the thumbtacks and not immediately perceive it as a separate and functional component available to be used in solving the task.
to stick the candle to the wall. Neither method works. However, if the task is presented with the tacks piled next to the box (rather than inside it), virtually all of the participants were shown to achieve the optimal solution, which is self defined.
The test has been given to numerous people, including M.B.A.
students at the Kellogg School of Management
in a study investigating whether living abroad and creativity are linked.
Glucksberg (1962) used a 2 × 2 design manipulating whether the tacks and matches were inside or outside of their boxes and whether subjects were offered cash prizes for completing the task quickly. Subjects who were offered no prize, termed low-drive, were told "We are doing pilot work on various problems in order to decide which will be the best ones to use in an experiment we plan to do later. We would like to obtain norms on the time needed to solve." The remaining subjects, termed high-drive, were told "Depending on how quickly you solve the problem you can win $5.00 or $20.00. The top 25% of the Ss [subjects] in your group will win $5.00 each; the best will receive $20.00. Time to solve will be the criterion used." The empty-boxes condition was found to be easier than the filled-boxes condition: more subjects solved the problem, and those who did solve the problem solved it faster. Within the filled-boxes condition, high-drive subjects performed worse than low-drive subjects. Glucksberg interpreted this result in terms of "neobehavioristic drive theory": "high drive prolongs extinction of the dominant habit and thus retards the correct habit from gaining ascendancy". An explanation in terms of the overjustification effect
is made difficult by the lack of a main effect for drive and by a nonsignificant trend in the opposite direction within the empty-boxes condition.
and W. M. Chaires found that having subjects repeat the names of common pairs of objects in this test, but in a different and unaccustomed linguistic structure, such as "box and tacks" instead of "box of tacks", facilitated performance on the candle problem. This phrasing helps one to distinguish the two entities as different and more accessible.
In a written version of the task given to people at Stanford University
, Michael C. Frank and language acquisition
researcher Michael Ramscar reported that simply underlining certain relevant materials ("on the table there is a candle, a box of tacks, and a book of matches...") increases the number of candle-problem solvers from 25% to 50%.
Cognitive test
Cognitive tests are assessments of the cognitive capabilities of humans and animals. Tests administered to humans include various forms of IQ tests; those administered to animals include the mirror test and the T maze test...
performance test, measuring the influence of functional fixedness
Functional fixedness
Functional fixedness is a cognitive bias that limits a person to using an object only in the way it is traditionally used. The concept of functional fixedness originated in Gestalt Psychology, a movement in psychology that emphasizes holistic processing...
on a participant's problem solving
Problem solving
Problem solving is a mental process and is part of the larger problem process that includes problem finding and problem shaping. Consideredthe most complex of all intellectual functions, problem solving has been defined as higher-order cognitive process that requires the modulation and control of...
capabilities. The test was created by Gestalt psychologist
Gestalt psychology
Gestalt psychology or gestaltism is a theory of mind and brain of the Berlin School; the operational principle of gestalt psychology is that the brain is holistic, parallel, and analog, with self-organizing tendencies...
Karl Duncker
Karl Duncker
Karl Duncker was a Gestalt psychologist. He attended Friedrich-Wilhelms-University from 1923 to 1923, spent 1925-1926 at Clark University in Worcester, MA as a visiting professor, where he received a masters in arts degree.Until 1935 he was a student and assistant of the founders of Gestalt...
and published posthumously in 1945. Duncker originally presented this test in his thesis on problem solving tasks at Clark University
Clark University
Clark University is a private research university and liberal arts college in Worcester, Massachusetts.Founded in 1887, it is the oldest educational institution founded as an all-graduate university. Clark now also educates undergraduates...
.
Problem
The test presents the participant with the following task: how to fix a lit candleCandle
A candle is a solid block or cylinder of wax with an embedded wick, which is lit to provide light, and sometimes heat.Today, most candles are made from paraffin. Candles can also be made from beeswax, soy, other plant waxes, and tallow...
on a wall (a cork board) in a way so the candle wax won't drip onto the table below. To do so, one may only use the following along with the candle:
- a book of matchesBook of matchesBook Of Matches is a poetry book written by Simon Armitage. It was first published in 1993 by Faber and Faber. Several poems featured in the book are studied as part of the GCSE English Literature examination in the UK.- The Book :...
- a boxBoxBox describes a variety of containers and receptacles for permanent use as storage, or for temporary use often for transporting contents. The word derives from the Greek πύξος , "box, boxwood"....
of thumbtacks
Solution
Response
Many of the people who attempted the test explored other creative, but less efficient, methods to achieve the goal. For example, some tried to tack the candle to the wall without using the thumbtack box, and others attempted to melt some of the candle’s wax and use it as an adhesiveAdhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...
to stick the candle to the wall. Neither method works. However, if the task is presented with the tacks piled next to the box (rather than inside it), virtually all of the participants were shown to achieve the optimal solution, which is self defined.
The test has been given to numerous people, including M.B.A.
Master of Business Administration
The Master of Business Administration is a :master's degree in business administration, which attracts people from a wide range of academic disciplines. The MBA designation originated in the United States, emerging from the late 19th century as the country industrialized and companies sought out...
students at the Kellogg School of Management
Kellogg School of Management
The Kellogg School of Management is the business school of Northwestern University in Evanston, Illinois, downtown Chicago, Illinois and Miami, Florida. Kellogg offers full-time, part-time, and executive programs, as well as partnering programs with schools in China, India, Hong Kong, Israel,...
in a study investigating whether living abroad and creativity are linked.
Glucksberg (1962) used a 2 × 2 design manipulating whether the tacks and matches were inside or outside of their boxes and whether subjects were offered cash prizes for completing the task quickly. Subjects who were offered no prize, termed low-drive, were told "We are doing pilot work on various problems in order to decide which will be the best ones to use in an experiment we plan to do later. We would like to obtain norms on the time needed to solve." The remaining subjects, termed high-drive, were told "Depending on how quickly you solve the problem you can win $5.00 or $20.00. The top 25% of the Ss [subjects] in your group will win $5.00 each; the best will receive $20.00. Time to solve will be the criterion used." The empty-boxes condition was found to be easier than the filled-boxes condition: more subjects solved the problem, and those who did solve the problem solved it faster. Within the filled-boxes condition, high-drive subjects performed worse than low-drive subjects. Glucksberg interpreted this result in terms of "neobehavioristic drive theory": "high drive prolongs extinction of the dominant habit and thus retards the correct habit from gaining ascendancy". An explanation in terms of the overjustification effect
Overjustification effect
The overjustification effect occurs when an external incentive such as money or prizes decreases a person's intrinsic motivation to perform a task. According to self-perception theory, people pay more attention to the incentive, and less attention to the enjoyment and satisfaction that they receive...
is made difficult by the lack of a main effect for drive and by a nonsignificant trend in the opposite direction within the empty-boxes condition.
Linguistic implications
E. Tory HigginsE. Tory Higgins
Edward Tory Higgins is Professor of Psychology at Columbia University and Professor of Management at the Columbia Business School. He is perhaps best known for developing Self-Discrepancy Theory.-Career:...
and W. M. Chaires found that having subjects repeat the names of common pairs of objects in this test, but in a different and unaccustomed linguistic structure, such as "box and tacks" instead of "box of tacks", facilitated performance on the candle problem. This phrasing helps one to distinguish the two entities as different and more accessible.
In a written version of the task given to people at Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
, Michael C. Frank and language acquisition
Language acquisition
Language acquisition is the process by which humans acquire the capacity to perceive, produce and use words to understand and communicate. This capacity involves the picking up of diverse capacities including syntax, phonetics, and an extensive vocabulary. This language might be vocal as with...
researcher Michael Ramscar reported that simply underlining certain relevant materials ("on the table there is a candle, a box of tacks, and a book of matches...") increases the number of candle-problem solvers from 25% to 50%.