Functional Fixedness: The Candle Problem Turns on the Box

Short answer. Functional fixedness is difficulty seeing a new use for an object that already has a familiar one. In Karl Duncker's candle problem, you must fix a candle to a wall using only a box of tacks and some matches; the answer, as later papers describe it, is to empty the box, tack it to the wall and stand the candle in it. The classic studies from 1945, 1952 and 1962 could be read here only as citations, so their results are not given. In a 2021 study, 56 of 69 students solved a drawn version within 8 minutes.

In one sentence: The candle problem turns on seeing the tack box as a shelf rather than a container, and the classic studies cited for it, including a 1962 study later cited for financial rewards, could be read here only as citations.

Outline5 sections

1. The puzzle and its answer
2. Box full, box empty
3. The 1962 reward study
4. How the result traveled
5. Rewards and creativity, more broadly

Figure 1. Outcomes for the candle problem in a 2021 study by Paula Ibáñez de Aldecoa, Sanne de Wit and Sabine Tebbich. Students saw a drawing of the materials and typed their answer, with up to 8 minutes.

In 2021, 85 university students in Amsterdam saw a drawing of a candle, matches and a box of pushpins. They had up to 8 minutes to type how they would fix the candle to a wall so the wax would not drip below. Sixteen said they already knew the answer. The puzzle is Karl Duncker's candle problem, the stock example of functional fixedness, and this page asks how much of its famous record you can still read.

The 2021 study, by Paula Ibáñez de Aldecoa, Sanne de Wit and Sabine Tebbich, appeared in Frontiers in Psychology under a CC BY license and could be read in full. The older work could not. Duncker's 1945 monograph, Robert Adamson's 1952 repetition and Sam Glucksberg's 1962 study each had a citation record here, but no abstract.

Study File

Experiment

Duncker's candle problem: fix a candle to a wall using only a box of tacks and matches; here, a 2021 run of a drawn version, read in full

Researcher and year

Karl Duncker, 1945, and Robert E. Adamson, 1952 (citations only); the 2021 run by Paula Ibáñez de Aldecoa, Sanne de Wit and Sabine Tebbich (full text)

Subjects

2021: 85 university students in Amsterdam, aged 18 to 30; 16 who already knew the solution were left out, leaving 69. Not read for 1945 and 1952.

Materials and delays

A drawing of a candle, a pack of matches and a box of pushpins on a screen; typed answer; up to 8 minutes; one session, no delay

Design

Correlational: habit tendency, measured with a slips-of-action task, compared with whether and how fast each student solved the problem

Main finding

56 of 69 (81.2%) solved within 8 minutes; habit tendency did not significantly predict solving (p = 0.169) or time to solve (p = 0.697)

Replication status

Replication tag: [single study] Habit tendency not shown to predict solving. University students, drawn version, one session; no independent replication read. Based on full text. Checked 2026-11-06. No tag for the classic claim that a full box makes the problem harder: the 1945 and 1952 studies were read only as citations.

Validity

Crossref lists no correction, retraction or expression of concern for any of the nine DOIs cited, including Duncker 1945, Adamson 1952, Glucksberg 1962 and the 2021 study (checked 2026-11-06).

Meaning for learners, within these conditions

In one timed session with a drawing, most students who did not already know the puzzle solved it. Whether a full box or a cash prize changes solving is not settled by what could be read.

This card as a spreadsheet (CSV, candle-problem-study-file.csv) · Where each value comes from (JSON)
Data: Ibáñez de Aldecoa, P., de Wit, S., & Tebbich, S. (2021). Can habits impede creativity by inducing fixation? Frontiers in Psychology 12: 683024, doi:10.3389/fpsyg.2021.683024, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/); Kroneisen, M., et al. (2021). How can I use it? The role of functional fixedness in the survival-processing paradigm. Psychonomic Bulletin & Review 28(1), 324–332, doi:10.3758/s13423-020-01802-y, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/); Duncker (1945), doi:10.1037/h0093599; Adamson (1952), doi:10.1037/h0062487 (citation records only; no values)

The puzzle and its answer

In the candle problem, as Meike Kroneisen and colleagues describe it in a 2021 paper, you are asked to fix a candle to a wall and light it. Besides the candle, you have only a matchbox and a box of thumbtacks. The answer is to empty the box, tack it to the wall, stand the candle in it and light it.

Functional fixedness is the name for what gets in the way. Kroneisen and colleagues define it as focusing on an object's common function while overlooking other functions that could solve the problem. Here, that means struggling to see the box as something that can hold the candle. They note that Duncker already used the term in 1945.

Figure 2. The shift the candle problem asks for, drawn from the descriptions in Kroneisen and colleagues (2021) and Ibáñez de Aldecoa and colleagues (2021).

Illustration

The materials of the candle problem as a 2021 paper describes them: a candle, a matchbox and a box of thumbtacks, with the candle to be fixed to a wall. A scene illustration; it does not show the answer.

The 2021 Amsterdam study scored an answer as correct only if it fixed the candle to the wall and treated the pushpin box as a platform, not only a container. Its question was whether people who lean on habits get stuck more often. The researchers measured habit tendency with a slips-of-action task, a computer task that counts how often people keep pressing a learned key for an outcome that now costs points.

Of the 69 students who did not already know the puzzle, 56 (81.2%) solved it and 13 did not. Habit tendency did not significantly predict who solved it (p = 0.169) or how fast (p = 0.697). The authors add that a drawing may show fixation less strongly than real objects in the hand.

Replication tag: [single study] Habit tendency not shown to predict solving the candle problem. University students in Amsterdam, drawn version with typed answers, one session of up to 8 minutes. No independent replication read. Based on full text. Checked 2026-11-06.

Box full, box empty

A classic variation asks whether the box is harder to see as a shelf when it arrives full of tacks. This page could not read the studies that tested it. Duncker's monograph, “On problem-solving,” appeared in Psychological Monographs in 1945, and only its citation record was available.

Adamson's 1952 paper in the Journal of Experimental Psychology is titled “Functional fixedness as related to problem solving: a repetition of three experiments.” Its citation record has no abstract, so this page does not say which experiments it repeated or what it found.

Figure 3. The comparison in Duncker's box version as Sonja Ebel and colleagues (2024) describe it. No counts are shown because the original study could be read only as a citation.

What remains are later descriptions. A 2024 paper by Sonja Ebel and colleagues, on functional fixedness in chimpanzees, describes Duncker's version as a “box problem” with three boxes. As Ebel and colleagues describe it, participants had to attach the boxes to a wall with tacks, set candles in them and light them. Fewer people solved it when the materials came inside the boxes than when they lay beside them.

A 2021 review by Antonio Osuna-Mascaró and Alice Auersperg adds a second detail of Duncker's work. According to the review, when he asked people to use the objects in their usual way before the test, fewer solved it. The one-candle puzzle described above is not the three-box setup in the 2024 account.

These are secondhand accounts, and the original numbers could not be read. So this page gives the full-box claim no replication tag. Fixation on a familiar use is one kind of getting stuck; this site's review of group brainstorming covers another, where a 2019 study offered fixation on a partner's ideas as one possible explanation for a narrower range of ideas.

The 1962 reward study

Sam Glucksberg's paper appeared in the Journal of Experimental Psychology in 1962. Its title is “The influence of strength of drive on functional fixedness and perceptual recognition.” Drive here means the strength of motivation to reach a goal. Neither Crossref nor Europe PMC holds an abstract for it, so its design, sample, conditions and times are not given here.

Figure 4. What could be read about Glucksberg's 1962 study, from the most to the least direct source.

The gap matters because later papers cite the 1962 study for a result about rewards. A 2013 paper in BMC Medical Education by Jeffrey Lyness and colleagues, citing Glucksberg, says that groups asked to solve the candle problem “take longer to solve the problem if they are promised a financial reward.”

The sentence names no box version and no size of delay. It also calls the solvers groups, a detail this page could not check. So this page does not say which versions the 1962 study compared or how much slower anyone was, and it gives the reward claim no tag.

How the result traveled

Laid out by date, the readable record is thinnest at the start, where the original results would be. Duncker in 1945, Adamson in 1952 and Glucksberg in 1962 could be read only as citations. In 2012, a meta-analysis on rewards and creativity by Kris Byron and Shalini Khazanchi appeared; its abstract could be read, and the next section covers it.

Figure 5. The sources on the candle problem read for this page, by year, with how much of each could be read.

In 2013, the Lyness paper used the candle problem as one example of a broader claim. Incentives, it says, increase desired behaviors on straightforward tasks but “actually produce poorer performance on tasks that require flexible, creative problem-solving.” The same paper lists Daniel Pink's 2009 book Drive among reviews of self-determination theory written for general readers. The book itself was not read for this page.

By 2021 the puzzle was familiar enough to get in the way of research. In the Amsterdam study, 16 of the 85 students (18.8%) said they already knew the problem and its solution, and their answers were left out. The 2021 review calls it a classic insight challenge in which people often hit an impasse before solving. The 2024 chimpanzee paper uses Duncker's box version as its example of functional fixedness in people.

Rewards and creativity, more broadly

The 2013 sentence speaks for rewards in general. The most direct general source read here is the Byron and Khazanchi meta-analysis in Psychological Bulletin. A meta-analysis pools the results of many studies. According to its abstract, it combined 60 experimental and nonexperimental studies, with 69 independent samples of children or adults.

Figure 6. The direction of the link between rewards and creative performance by type of reward, as the abstract of Byron and Khazanchi (2012) reports it, set beside the 2013 summary. The abstract gives no effect sizes.

The abstract reports that the direction depended on what the reward was for. Rewards tied to creativity itself tended to increase creative performance, more so when people got positive, task-focused feedback and more choice. Rewards for performing or completing a task tended to have a slight negative effect. Whether the pooled results were corrected for publication bias could not be checked.

[status not assigned] Direction of the link between rewards and creative performance, by reward type. Children and adults, 60 experimental and nonexperimental studies. The abstract reports no effect sizes, and bias correction was not checked. Based on the abstract. Checked 2026-11-06.

So the abstract draws a narrower line than the 2013 summary, and neither is a test of the candle problem itself. Getting unstuck by setting a problem aside is a separate line of research, covered in this site's deep read on the incubation effect.

If you plan to use the candle problem in a class or a talk, ask first who has already seen it; in the 2021 study, nearly one in five students had. If you cite it on rewards, name the 1962 paper by its title and year, and say that the reward detail comes from later summaries.

Data: Candle problem sources and what each supports

Claim	Source	Read as	Value (quoted)	Value (recomputed)	Tag
Monograph titled On problem-solving	Duncker 1945	citation only	–	–	none (citation only)
In Duncker's box version (three boxes, candles to set in them), fewer people solved when the materials were inside the boxes than beside them	Duncker 1945, as described by Ebel et al. 2024	full text	3 boxes	–	none (secondhand)
When Duncker asked people to use the objects in their usual way before the test, fewer solved it	Duncker 1945, as described by Osuna-Mascaró & Auersperg 2021	full text	–	–	none (secondhand)
Paper titled Functional fixedness as related to problem solving: a repetition of three experiments	Adamson 1952	citation only	–	–	none (citation only)
Paper titled The influence of strength of drive on functional fixedness and perceptual recognition	Glucksberg 1962	citation only	–	–	none (citation only)
Lyness et al. list Pink's book Drive: The Surprising Truth About What Motivates Us among reviews of self-determination theory for lay audiences; the book itself was not read	Pink 2009, as listed by Lyness et al. 2013	full text	–	–	none (secondhand)
Groups promised a financial reward took longer to solve the candle problem; no box version or size of delay given	Glucksberg 1962, as described by Lyness et al. 2013	full text	–	–	none (secondhand)
Meta-analysis of rewards and creative performance: studies pooled	Byron & Khazanchi 2012	abstract	60 studies	–	none
Meta-analysis of rewards and creative performance: independent samples	Byron & Khazanchi 2012	abstract	69 independent samples	–	none
Rewards contingent on creativity tended to increase creative performance	Byron & Khazanchi 2012	abstract	–	–	[status not assigned]
Rewards contingent on performance or completion tended to have a slight negative effect on creative performance	Byron & Khazanchi 2012	abstract	–	–	[status not assigned]
Lyness et al. state that incentives produce poorer performance on tasks that require flexible, creative problem-solving; a broad summary, reward types not separated	Lyness et al. 2013	full text	–	–	none
Students who said they already knew the candle problem and its solution	Ibáñez de Aldecoa, de Wit & Tebbich 2021	full text	16 of 85 students	18.8%	none
Students who solved the drawn candle problem within 8 minutes	Ibáñez de Aldecoa, de Wit & Tebbich 2021	full text	56 of 69 students	81.2%	none
Habit tendency did not significantly predict solving the candle problem	Ibáñez de Aldecoa, de Wit & Tebbich 2021	full text	p = 0.169	–	Replication tag: [single study]
Functional fixedness means focusing on an object's common function and overlooking others; in the candle problem, the answer is to empty the box, tack it to the wall and stand the candle in it	Kroneisen et al. 2021	full text	–	–	none
Kroneisen et al. note that Duncker already used the term functional fixedness in 1945 and cite his monograph for the candle problem	Duncker 1945, as described by Kroneisen et al. 2021	full text	–	–	none (secondhand)

Download the data (CSV, candle-problem-studies.csv) · Where each value comes from (JSON) Data: Ibáñez de Aldecoa, P., de Wit, S., & Tebbich, S. (2021). Can habits impede creativity by inducing fixation? Frontiers in Psychology 12: 683024, doi:10.3389/fpsyg.2021.683024, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/); Byron, K., & Khazanchi, S. (2012). Rewards and creative performance: A meta-analytic test of theoretically derived hypotheses. Psychological Bulletin 138(4), 809–830, doi:10.1037/a0027652 (abstract; quoted values, publisher's terms apply); Lyness, J. M., Lurie, S. J., Ward, D. S., Mooney, C. J., & Lambert, D. R. (2013). Engaging students and faculty. BMC Medical Education 13: 151, doi:10.1186/1472-6920-13-151, CC BY 2.0 (https://creativecommons.org/licenses/by/2.0/) (text; no values); Ebel, S. J., et al. (2024). Functional fixedness in chimpanzees. Scientific Reports 14: 12155, doi:10.1038/s41598-024-62685-w, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) (text; one value); Osuna-Mascaró, A. J., & Auersperg, A. M. I. (2021). Current understanding of the “insight” phenomenon across disciplines. Frontiers in Psychology 12: 791398, doi:10.3389/fpsyg.2021.791398, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) (text; no values); Kroneisen, M., et al. (2021). How can I use it? The role of functional fixedness in the survival-processing paradigm. Psychonomic Bulletin & Review 28(1), 324–332, doi:10.3758/s13423-020-01802-y, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) (text; no values); Duncker (1945), doi:10.1037/h0093599; Adamson (1952), doi:10.1037/h0062487; Glucksberg (1962), doi:10.1037/h0044683 (citation records only; no values)

Retrieval check

Answer from memory first, then follow the link to the passage and check.

1. What does the candle problem ask you to do, and which object holds the answer? Back to the passage
2. What can be read about the 1962 study cited for financial rewards, and what cannot? Back to the passage
3. According to the 2012 abstract, which kind of reward tended to raise creative performance? Back to the passage · Setting a problem aside: the incubation effect

Sources

1. Duncker, K. (1945). On problem-solving. Psychological Monographs, 58(5), i–113. doi:10.1037/h0093599 https://doi.org/10.1037/h0093599Read: citation only · no abstract available to read, so no results, numbers or tags are taken from it · its box version is described on this page only as later papers report it · checked 2026-11-06
2. Adamson, R. E. (1952). Functional fixedness as related to problem solving: A repetition of three experiments. Journal of Experimental Psychology, 44(4), 288–291. doi:10.1037/h0062487 https://doi.org/10.1037/h0062487Read: citation only · no abstract available to read, so no results, numbers or tags are taken from it · checked 2026-11-06
3. Glucksberg, S. (1962). The influence of strength of drive on functional fixedness and perceptual recognition. Journal of Experimental Psychology, 63(1), 36–41. doi:10.1037/h0044683 https://doi.org/10.1037/h0044683Read: citation only · no abstract available to read, so no design, sample, conditions, times or tags are taken from it · checked 2026-11-06
4. Pink, D. H. (2009). Drive: The surprising truth about what motivates us. New York: Riverhead Books. As listed by Lyness et al. (2013). https://doi.org/10.1186/1472-6920-13-151Read: citation only · the book was not read, and nothing on this page says what it claims · checked 2026-11-06
5. Byron, K., & Khazanchi, S. (2012). Rewards and creative performance: A meta-analytic test of theoretically derived hypotheses. Psychological Bulletin, 138(4), 809–830. doi:10.1037/a0027652 https://doi.org/10.1037/a0027652Read: abstract · [status not assigned] direction of the link between rewards and creative performance by reward type, children and adults, 60 studies, abstract gives no effect sizes and bias correction was not checked · checked 2026-11-06
6. Lyness, J. M., Lurie, S. J., Ward, D. S., Mooney, C. J., & Lambert, D. R. (2013). Engaging students and faculty: Implications of self-determination theory for teachers and leaders in academic medicine. BMC Medical Education, 13, 151. doi:10.1186/1472-6920-13-151 https://doi.org/10.1186/1472-6920-13-151Read: full text · a summary that cites the 1962 study · it supports no tag here · checked 2026-11-06 · Text license: CC BY 2.0
7. Ibáñez de Aldecoa, P., de Wit, S., & Tebbich, S. (2021). Can habits impede creativity by inducing fixation? Frontiers in Psychology, 12, 683024. doi:10.3389/fpsyg.2021.683024 https://doi.org/10.3389/fpsyg.2021.683024Read: full text · Replication tag: [single study] habit tendency not shown to predict solving the candle problem, university students in Amsterdam, drawn version, one session · checked 2026-11-06 · Text license: CC BY 4.0
8. Kroneisen, M., Kriechbaumer, M., Kamp, S.-M., & Erdfelder, E. (2021). How can I use it? The role of functional fixedness in the survival-processing paradigm. Psychonomic Bulletin & Review, 28(1), 324–332. doi:10.3758/s13423-020-01802-y (published online 2020) https://doi.org/10.3758/s13423-020-01802-yRead: full text · used only for its description of the candle problem and its definition of functional fixedness · no tag · checked 2026-11-06 · Text license: CC BY 4.0
9. Osuna-Mascaró, A. J., & Auersperg, A. M. I. (2021). Current understanding of the “insight” phenomenon across disciplines. Frontiers in Psychology, 12, 791398. doi:10.3389/fpsyg.2021.791398 https://doi.org/10.3389/fpsyg.2021.791398Read: full text · secondhand description of Duncker's work · it supports no tag here · checked 2026-11-06 · Text license: CC BY 4.0
10. Ebel, S. J., Völter, C. J., Sánchez-Amaro, A., Helming, K. A., Herrmann, E., & Call, J. (2024). Functional fixedness in chimpanzees. Scientific Reports, 14, 12155. doi:10.1038/s41598-024-62685-w https://doi.org/10.1038/s41598-024-62685-wRead: full text · secondhand description of Duncker's box version · it supports no tag here · checked 2026-11-06 · Text license: CC BY 4.0
11. Crossref. Work records and update searches (corrections, retractions, expressions of concern) for the nine DOIs cited on this page. https://api.crossref.org/works?filter=updates:10.1037/h0044683record check · no correction, retraction or expression of concern registered for the nine DOIs · checked 2026-11-06

Cite this page

Feedback & Forgetting. (2026-11-06). Functional Fixedness: The Candle Problem Turns on the Box. https://feedbackandforgetting.com/creative-minds/candle-problem/ (accessed [date you read it])

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