management fads

The Candle Problem: Balderdash Masquerading as Science

UPDATED 04/12/12

The hot new item in management “science” appears to be the Candle Problem. Graham Morehead discusses the problem and its broader, “scientifically” supported conclusions:

The Candle Problem was first presented by Karl Duncker. Published posthumously in 1945, “On problem solving” describes how Duncker provided subjects with a candle, some matches, and a box of tacks. He told each subject to affix the candle to a cork board wall in such a way that when lit, the candle won’t drip wax on the table below (see figure at right). Can you think of the answer?

The only answer that really works is this: 1.Dump the tacks out of the box, 2.Tack the box to the wall, 3.Light the candle and affix it atop the box as if it were a candle-holder. Incidentally, the problem was much easier to solve if the tacks weren’t in the box at the beginning. When the tacks were in the box the participant saw it only as a tack-box, not something they could use to solve the problem. This phenomenon is called “Functional fixedness.”

Sam Glucksberg added a fascinating twist to this finding in his 1962 paper, “Influece of strength of drive on functional fixedness and perceptual recognition.” (Journal of Experimental Psychology 1962. Vol. 63, No. 1, 36-41). He studied the effect of financial incentives on solving the candle problem. To one group he offered no money. To the other group he offered an amount of money for solving the problem fast.

Remember, there are two candle problems. Let the “Simple Candle Problem” be the one where the tacks are outside the box — no functional fixedness. The solution is straightforward. Here are the results for those who solved it:

Simple Candle Problem Mean Times :

  • WITHOUT a financial incentive : 4.99 min
  • WITH a financial incentive : 3.67 min

Nothing unexpected here. This is a classical incentivization effect anybody would intuitively expect.

Now, let “In-Box Candle Problem” refer to the original description where the tacks start off in the box.

In-Box Candle Problem Mean Times :

  • WITHOUT a financial incentive : 7:41 min
  • WITH a financial incentive : 11:08 min

How could this be? The financial incentive made people slower? It gets worse — the slowness increases with the incentive. The higher the monetary reward, the worse the performance! This result has been repeated many times since the original experiment.

Glucksberg and others have shown this result to be highly robust. Daniel Pink calls it a legally provable “fact.” How should we interpret the above results?

When your employees have to do something straightforward, like pressing a button or manning one stage in an assembly line, financial incentives work. It’s a small effect, but they do work. Simple jobs are like the simple candle problem.

However, if your people must do something that requires any creative or critical thinking, financial incentives hurt. The In-Box Candle Problem is the stereotypical problem that requires you to think “Out of the Box,” (you knew that was coming, didn’t you?). Whenever people must think out of the box, offering them a monetary carrot will keep them in that box.

A monetary reward will help your employees focus. That’s the point. When you’re focused you are less able to think laterally. You become dumber. This is not the kind of thing we want if we expect to solve the problems that face us in the 21st century.

All of this is found in a video (to which Morehead links), wherein Daniel Pink (an author and journalist whose actual knowledge of science and business appears to be close to zero) expounds the lessons of the Candle Problem. Pink displays his (no-doubt-profitable) conviction that the Candle Problem and related “science” reveals (a) the utter bankruptcy of capitalism and (b) the need to replace managers with touchy-feely gurus (like himself, I suppose). That Pink has worked for two of the country’s leading anti-capitalist airheads — Al Gore and Robert Reich — should tell you all that you need to know about Pink’s real agenda.

Here are my reasons for sneering at Pink and his ilk:

1. I have been there and done that. That is to say, as a manager, I lived through (and briefly bought into) the touchy-feely fads of the ’80s and ’90s. Think In Search of Excellence, The One Minute Manager, The Seven Habits of Highly Effective People, and so on. What did anyone really learn from those books and the lectures and workshops based on them? A perceptive person would have learned that it is easy to make up plausible stories about the elements of success, and having done so, it is possible to make a lot of money peddling those stories. But the stories are flawed because (a) they are based on exceptional cases; (b) they attribute success to qualitative assessments of behaviors that seem to be present in those exceptional cases; and (c) they do not properly account for the surrounding (and critical) circumstances that really led to success, among which are luck and rare combinations of personal qualities (e.g., high intelligence, perseverance, people-reading skills). In short, Pink and his predecessors are guilty of reductionism and the post hoc ergo propter hoc fallacy.

2. Also at work is an undue generalization about the implications of the Candle Problem. It may be true that workers will perform better — at certain kinds of tasks (very loosely specified) — if they are not distracted by incentives that are related to the performance of those specific tasks. But what does that have to do with incentives in general? Not much, because the Candle Problem is unlike any work situation that I can think of. Tasks requiring creativity are not performed under deadlines of a few minutes; tasks requiring creativity are (usually) assigned to persons who have demonstrated a creative flair, not to randomly picked subjects; most work, even in this day, involves the routine application of protocols and tools that were designed to produce a uniform result of acceptable quality; it is the design of protocols and tools that requires creativity, and that kind of work is not done under the kind of artificial constraints found in the Candle Problem.

3. The Candle Problem, with its anti-incentive “lesson,” is therefore inapplicable to the real world, where incentives play a crucial and positive role:

  • The profit incentive leads firms to invest resources in the development and/or production of things that consumers are willing to buy because those things satisfy wants at the right price.
  • Firms acquire resources to develop and produce things by bidding for those resources, that is, by offering monetary incentives to attract the resources required to make the things that consumers are willing to buy.
  • The incentives (compensation) offered to workers of various kinds (from scientists with doctorates to burger-flippers) are generally commensurate with the contributions made by those workers to the production of things of value to consumers, and to the value placed on those things by consumers.
  • Workers agree to the terms and conditions of employment (including compensation) before taking a job. The incentive for most workers is to keep a job by performing adequately over a sustained period — not by demonstrating creativity in a few minutes. Some workers (but not a large fraction of them) are striving for performance-based commissions, bonuses, and profit-sharing distributions. But those distributions are based on performance over a sustained period, during which the striving workers have plenty of time to think about how they can perform better.
  • Truly creative work is done, for the most part, by persons who are hired for such work on the basis of their credentials (education, prior employment, test results). Their compensation is based on their credentials, initially, and then on their performance over a sustained period. If they are creative, they have plenty of psychological space in which to exercise and demonstrate their creativity.
  • On-the-job creativity — the improvement of protocols and tools by workers using them — does not occur under conditions of the kind assumed in the Candle Problem. Rather, on-the-job creativity flows from actual work and insights about how to do the work better. It happens when it happens, and has nothing to do with artificial time constraints and monetary incentives to be “creative” within those constraints.
  • Pink’s essential pitch is that incentives can be replaced by offering jobs that yield autonomy (self-direction), mastery (the satisfaction of doing difficult things well), and purpose (that satisfaction of contributing to the accomplishment of something important). Well, good luck with that, but I (and millions of other consumers) want what we want, and if workers want to make a living they will just have to provide what we want, not what turns them on. Yes, there is a lot to be said for autonomy, mastery, and purpose, but there is also a lot to be said for getting a paycheck. And, contrary to Pink’s implication, getting a paycheck does not rule out autonomy, mastery, and purpose — where those happen to go with the job.

Pink and company’s “insights” about incentives and creativity are 180 degrees off-target. McDonald’s could use the Candle Problem to select creative burger-flippers who will perform well under tight deadlines because their compensation is unrelated to the creativity of their burger-flipping. McDonald’s customers should be glad that McDonald’s has taken creativity out of the picture by reducing burger-flipping to the routine application of protocols and tools.


In an e-mail to a friend, I put it this way:

The Candle Problem is an interesting experiment, and probably valid with respect to the performance of specific tasks against tight deadlines. I think the results apply whether the stakes are money or any other kind of prize. The experiment illustrates the “choke” factor, and nothing more profound than that.

I question whether the experiment applies to the usual kind of incentive (e.g., a commissions or bonus), where the “incentee” has ample time (months, years) for reflection and research that will enable him to improve his performance and attain a bigger commission or bonus (which usually isn’t an all-or-nothing arrangement).

There’s also the dissimilarity of the Candle Problem — which involves more-or-less randomly chosen subjects, working against an artificial deadline — and actual creative thinking — usually involving persons who are experts (even if the expertise is as mundane as ditch-digging), working against looser deadlines or none at all.