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Functional Fixedness
Functional Fixedness
Functional Fixedness
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Things were better when you were 5-years-old. 

According to the research, that’s the age when you most used objects around you in a truly creative way to achieve your goals. So your spoon transformed into a catapult; your family dog into a movable ladder; and your parent’s mobile phone into a high-tech submarine. 

Then you got old. The world became more known, more familiar... and Functional Fixedness kicked in. 

Functional Fixedness is a heuristic that prevents you from using familiar objects in new or innovative ways.


Like any heuristic, Functional Fixedness serves an important purpose. It means you don’t have to expend serious cognitive effort when picking up a hammer, jumping into a car, or seeing a kettle. Instead, your Fast Thinking mind can identify and use those objects efficiently and effectively. And, like any heuristic, this strength can also become a limiting bias — particularly when you need to innovate.

Breaking out of Functional Fixedness will take conscious effort and systems to interrupt your tendency to ‘stereotype’ the objects around you. Further, the 5-year-old story at the lead of this summary is a reminder that Functional Fixedness tends to be strengthened with greater knowledge or experience in a particular domain. 


On a business level, Functional Fixedness will likely be the difference between irrelevancy and realising innovative new approaches. 

This will often consist of 'pivoting' — think the gin companies that moved to disinfectant production during Covid, or the amazing backstory to tech startup Slack — see the In Practice section below for more on both. 

The point is that breaking Functional Fixedness allows businesses to use existing capital, equipment, markets and resources in new and unexpected ways to stay relevant. 


On a personal level, consciously interrupting it will enable you to use familiar objects and tools in creative ways to achieve your goals. Want to tighten that screw but can’t find your screwdriver? Rather than spending the next hour searching, simply use the coin in your pocket. 

It also helps you to truly value and make the best use of the options currently at your disposal — see the In Practice section below for the classic Candle Problem for a tale of 'out of the box thinking.' 

On an interpersonal level, it explains your tendency to stereotype people and their behaviour or messages. For example, that obnoxious person who you normally avoid might actually provide you with insightful feedback one day — you’ll miss it unless you challenge Functional Fixedness. 


You can better understand Functional Fixedness in the context of an understanding of Mental Models. Your fixed view of how to use a hammer is simply reflective of a mental model you have of that object. And, like all mental models, it’s useful to consider the Map vs Territory to understand that every object is more than your simplified mental representation of it. 

As a heuristic, Functional Fixedness can be traced back to Fast and Slow Thinking. In terms of specifics, it shares some elements with the Confirmation Heuristic, in that it leads you to assert your existing beliefs and mental models in a given situation.

In terms of countering this heuristic, you might apply First Principles or even Idea Sex — see Actionable Takeaways below for more. It also might challenge the Sunk Cost Fallacy, by finding ways to actually realise the value of past investments.

And finally, on a business and even economic level, this model has some links to Creative Destruction, in which existing models actually drive the creation of new ones.

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Actionable Takeaways
  • Seperate the task from the solution. 

It’s all too easy to jump to a solution complete with a task list and five-point plan. This model is a reminder to maintain clarity on the outcome you want but to be flexible on how you reach that goal. 

  • Build-in diversity to interrupt the bias. 

Interrupt Functional Fixedness with diversity. You can do this by organising cross-functional teams to review or ideate around a project or on a personal level by diversifying your thought by using sites like ModelThinkers to expand your cross-domain mental models. 

  • Apply First Principles. 

Consider how you might apply First Principles to cut through your assumptions. What is the essence of the problem and the resources at your disposal? This approach involves embracing a beginner's mind and is harder than it sounds. 

  • Play. 

Yes. You read that right — actively develop a playful mind that asks ‘what if’ questions and explores with curiosity. Embrace that lost 5-year-old with an unstructured, playful approach to challenge Functional Fixedness. 

  • Recombine the elements. 

Have you ever played Scrabble or other word games and found yourself stuck? Then, simply shuffling the letters at your disposal opened up new options? The same applies to other contexts — consider how to ‘recombine’ elements to help you reframe and see them differently. 

  • Ask: ‘how might we use this differently?’

Simply ask the question — ‘how might we use this differently?’ Doing this as a habit will help you to develop a creative approach to situations and resources around you. It also might help you to find ways to turn challenges into opportunities, as you reframe and consider potential benefits. 


There are few substantial critiques of Functional Fixedness and it is a reasonably accepted heuristic. There have been some debates on nuances — for example, one study claiming that monetary incentives made Functional Fixedness worse, with another unable to repeat that result. But I was unable to find any studies that deny its existence or impact. 

Indeed, variations on the Candle Problem persist — with a written version delivered at Stanford University resulting in similar results.

Functional Fixedness was even put to the test with non-industrialised societies to determine the impact of cultural factors — with a recent study conducted within the Amazon region of Ecuador to compare with industrial culture. The results seemed to demonstrate that Functional Fixedness is culture blind and not related to the level of industrialisation or technology of a society. 

In Practice

Adapting during coronavirus. 

Much of our world changed during 2020. Many people were left with redundant buildings or businesses that relied on pre-Covid conditions and practices. 

Meanwhile, some companies broke through Functional Fixedness to reinvent themselves. A wonderful example of this was the Rubbens gin distillery in Belgium which moved quickly, redirecting its production of alcohol to produce disinfectant by March 2020. Other distilleries around the world soon followed suit. 

Breaking Functional Fixedness in tech startups. 

About a decade ago Canadian billionaire Daniel Butterfield, was trying to launch an online game called Glitch. Ever heard of it? Me neither. 

At the time the team created an internal messaging system to coordinate their work on the game. It was a little while in before they realised that the messaging system had more value than the game itself — and so Slack was launched. 

The Candle Problem.

This model is still best described through Duncker’s original Candle Problem from 1945. In the experiment, participants were given the following objects: 

  • A box of thumbnails

  • Matches

  • A candle

They were then asked to attach the candle to the wall while ensuring that wax would not drip on the table below once lit. The clock is ticking, how would you solve this problem? Pause for a moment and consider what you would do.

You might try pinning the candle directly to the wall or melting the candle to stick it to the wall. Both would leave the table covered in wax as the candle burnt down. A small proportion of people discovered the real solution. 

Meanwhile, another group of participants were given the same task, but were given the following objects: 

  • A box

  • Thumbnails

  • Matches

  • A candle

For those playing at home, you’ll notice that the object list is identical to the first one — only this time the thumbnails were not placed in the box.

This subtle change made the ‘box’ an object in itself and a potential part of the solution rather than just a container for thumbnails. It broke the Functional Fixedness related to, dare I say it, ‘in the box thinking.’

This slight tweak resulted in almost all participants solving the problem — simply pinning the box to the wall and placing the candle inside it. 

Angels on a pin. 

Angels on a Pin is a 1959 essay by American academic test designer Alexander Calandra describing a case where a colleague was about to give a student zero to a Physics question. The question was ‘Show how it is possible to determine the height of a building with the aid of a barometer.'

The student's answer was to tie the barometer to a rope, lower the rope and measure the resulting distance. Technically correct, but not the physics assessment they were looking for. 

The academics decided to give the student another chance, asking them to demonstrate knowledge of physics in their next attempt. The student’s second answer was to drop the barometer from the top of the roof and time how long it took to hit the ground, then use the formula S = 0.5at squared to calculate the height. 

The student was able to offer several other options including measuring the barometer versus building shadows, creating a pendulum with the barometer and comparing gravity at the different heights, or offer the barometer to the superintendent if he revealed the height of the building. 

All of the answers continued to expose the Functional Fixedness of the academics who crafted the original question. 

Build your latticework
This model will help you to:


Origins & Resources

The term Functional Fixedness was coined by Karl Duncker in 1945, who described it as a “mental block against using an object in a new way that is required to solve a problem.” His original study involved the Candle Problem, outlined in the overview above. 

This Candle Problem, in many ways, has become a de facto test of creative insights, leading to the 2009 study by William Maddux and Adam Galinsky to assess the impact of travelling and living overseas on creativity — they concluded that a period spent adjusting to living (not just travelling) abroad did increase creativity.

My Notes

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