It is the tendency to see objects as only working in a particular way. You might view a thumbtack as something that can only be used to hold paper to a corkboard.
Functional fixedness can prevent people from seeing other uses for an object. It can also diminish our ability to think of creative solutions to problems.
MORE IDEAS FROM THE ARTICLE
If you have two candles, numerous thumbtacks, and a box of matches, try to figure out how to mount the candles to the wall.
Answer: Using the matches, melt the bottom part of each candle, then use the hot wax to stick the candle to the matchbox. Then use the thumbtacks to attach the box to the wall.
Due to functional fixedness, many people might try to use the thumbtacks directly to fix the candles to the wall. They may consider it as the only way to use the thumbtacks.
Is the act of deconstructing something to the fundamental parts that you know are true and building up from there.
Also called reasoning from first principles, it effectively helps many great thinkers to break down complicated problems and generate original solutions while teaching how to think for oneself.