Duncker's Candle: Are You Solving the Right Problem?

In 1945, the psychologist Karl Duncker gave participants a wax candle, a box of thumbtacks, and a book of matches. Their task: affix the candle to the wall. Only about 25% found the optimal solution.

Duncker reports that most people tried to melt the wax and stick the candle directly to the wall, or contort the tacks into some kind of support. They were solving the problem — just not very well. Then Duncker made one small change. He presented the same materials, but with the tacks placed outside the box. Almost everyone solved it immediately. They tacked the box to the wall and set the candle inside it.

Same materials. Completely different outcome.

When the tacks were inside the box, people saw the box as a container. The moment the tacks were separated, the box became something else — a shelf, a platform, a solution. Duncker called this phenomenon functional fixedness: the tendency to see an object only in terms of its conventional use, even when a better use is sitting right in front of you.

Most people nod at this story and think about product design or innovation. We think about marketing.

Take cheese. When marketers think about differentiating a cheese brand, they tend to reach for the same set of levers — flavor, texture, variety, quality, price. Those are the tacks in the box. Everyone in the category is working from the same list, optimizing against the same attributes, watching the same competitors. The result is a category full of brands solving the same problem in slightly different ways.

Kellogg alum Ann Legan faced exactly this situation with Babybel in the United States. Rather than compete on the familiar category attributes, she looked at something the category had largely ignored: the usage occasion. She repositioned Babybel not as a cheese but as a healthy snack — a portable, portion-controlled product that offered indulgence without the guilt. She took the tacks out of the packaging, so to speak, and suddenly people saw new usage occasions.

The brand grew significantly. Not because the product changed, but because the problem being solved changed.

This is what competitor obsession can cost you. When you spend most of your energy watching what everyone else in your category is doing, you inherit their blind spots along with their playbook. You risk getting better and better at solving the wrong problem. The brands that break through tend to be the ones that stepped back and asked a different question — not "how do we win on the attributes everyone is competing on?" but "what problem are we actually in a position to solve for our customers that nobody else is solving?"

Next time you sit down to plan your marketing, remember Duncker's candle. The materials you need may already be on the table. The question is whether you can see them for what they are.