Free for a minute? Try this, if you will.

There are three cans in front of you. The green can hold 21 litres. The red 127 litres and blue 3 litres. There’s a tank full of water. You need to fill the can with exactly 100 litres. How will you do it?

You take the red and fill it to its capacity, i.e., 127 litres. And pour it in green. Now the red has 106 litres remaining. You pour it twice in blue, and bingo the red has 100 litres.

Red minus green minus twice blue is equal to 100.

Well done!

Try a similar question. There are three cans. The green can hold 15 litres. The red 39 litres. The blue 3 litres. Fill the can with exactly 18 litres.

Stop reading. Think about the answer.

…..

You say you will take the red one; fill it fully, i.e., 39 litres. You’ll pour it in green. Now the red has 24 litres. You pour it twice in the blue and bingo the red now has 18 litres.

Again. Red minus green minus twice blue is equal to 18.

You are right. But you got it all wrong!

There was simpler way of doing this. You just had to fill the 15-litre green can and the 3-litre blue can and pour it in the red one and you would have got 18 litres.

Yahtzee!

Why did you circumvent your head to touch your nose when you could have touched it straight?

Blame it on the Einstellung Effect. Einstellung is German for approach. It describes how prior knowledge and repeated doing of something can become a hindrance to creative problem-solving. Often times, we use old proven methods to solve new problems without stopping to think if it’s the right method at all.

People rely on existing thought patterns (aka cognitive structures) even when they are not relevant to the new problem at hand. They start doing it by force of habit. And end up getting it wrong. Just like you.

If you are expert at something, watch out. Your very expertise can pull you down and lead you to ineffective solutions, if you are lucky and incorrect solutions, if you are unlucky. 

Einstellung Effect explains why gaining expertise in a domain can make us less creative at problem-solving. It tends to produce rigid thinking. Rigidity is what stifles creative thinking and innovation.

How does one avoid the Einstellung Effect? To know you may have it, is a good starting point!