Functional fixedness is the tendency to perceive objects only in terms of their conventional functions, which can prevent people from using objects in novel ways to solve problems. Karl Duncker (1945) demonstrated this with the candle problem: given a candle, a box of thumbtacks, and matches, participants struggled to find the solution (tack the box to the wall as a shelf and place the candle on it) because they saw the box only as a container for tacks, not as a potential shelf.
Key Demonstrations
Duncker's candle problem and Maier's two-string problem (attaching a weight to one string to create a pendulum that swings close enough to grasp) are classic demonstrations. In both cases, perceiving an object's non-obvious function is the key to solution. Performance improves when the object is presented outside its typical functional context (e.g., tacks presented outside the box), demonstrating that functional fixedness arises from the association between objects and their conventional uses.
Relation to Experience and Expertise
Functional fixedness increases with experience — the more familiar an object's conventional function, the harder it is to see alternative uses. Children, who have less entrenched functional knowledge, sometimes show less functional fixedness than adults. In contrast, creative experts may overcome functional fixedness through techniques like conceptual blending, constraint relaxation, and systematic variation of assumptions.
Research suggests several strategies for overcoming functional fixedness. The generic parts technique involves decomposing objects into their basic parts and properties, stripping away functional labels. Thinking about what an object is made of (material, shape, size) rather than what it is used for can help generate novel uses. Environmental changes, including exposure to other cultures or unfamiliar tools, can also reduce fixedness by weakening the association between objects and their conventional functions.