Are You Ever Blind to the Obvious?


Sometimes we get so set in our ways that we fail to notice an easier way to do things, simply because it's not the way we typically solve a problem. By allowing ourselves to use different parts of our brain to accomplish even simple tasks, we won't continue to limit our growth.

Do you ever do things the same old way because, well, that’s how you do them — even when there's a simpler or more efficient way?

We’re creatures of habit. We’re also creatures of familiarity. And many people are creatures of not rocking the boat, which translates into doing things the same old way rather than seeking a better way—or noticing a better way that’s readily available if only we can come out of our trance state and look around.

In his fascinating book, Why We Make Mistakes, Joseph Hallinan describes how easily we go on auto-pilot and how to avoid it. He reports the following research. In one experiment, researchers gave people the following challenge, using 3 jars of water:
-- Jar A holds 21 cups of water.
-- Jar B holds 127 cups of water.
-- Jar C holds 3 cups of water.
The challenge? How would you get exactly 100 cups of water?

Can you figure it out? Give it a try before you read further.
Here’s the solution:
-- Pour Jar B into Jar A till it’s full, leaving 106 cups in Jar B.
-- Pour Jar B into Jar C till it’s full, leaving 103 cups in Jar B.
-- Dump out the water in Jar C, and again pour Jar B into Jar C till it’s full.
-- You now have exactly 100 cups of water in Jar B.
I love problems like this!
The researchers had subjects solve several problems that followed the same pattern -- Jar B into Jar A once, then Jar B into Jar C twice – till they became familiar with the pattern.
Then they posed a new problem, such as this one:
-- Jar A holds 14 cups
-- Jar B holds 36 cups
-- Jar C holds 8 cups
The challenge: How would you get exactly 6 cups of water? Try it.
If you followed the same pattern as before, you poured Jar B into Jar A, leaving 22 cups in Jar B. Then you poured Jar B into Jar C, leaving 14 cups in Jar B. Then Jar B into Jar C again, leaving the required 6 cups in Jar B.
That’s what the majority of research subjects did. In running the experiment thousands of times, researchers found that between 64% and 83% of the subjects continued to use this same pattern – even (and here’s the kicker) when a much simpler solution was available.
Did you come up with the much simpler solution? It’s at the end of this post in case you want to think about it a little more before viewing the answer.
But get this: When the researchers tried this second problem on a new group of subjects who had not been given the first round of problems, between 95% and 99% figured out the simpler solution.
The compelling conclusion, as described by Hallinan: “People in the initial experiments became so set in their ways that they were blinded to the newer, simpler solution. But to those who came to the problem fresh, the simpler solution was obvious.”
This research is an excellent reminder that we should resist becoming so tied to certain ways of doing things that we become blinded to newer, better or simpler ways.

And here’s the simpler solution: Simply pour Jar A into Jar C and you’re left with 6 cups in Jar A. Voila!

User Comments

Mirkeya capellan's picture

Naomi - Great post!! that is so true!! ....Habits are bad to break but we should look for other ways of doing things. Change is always good!!

August 18, 2011 - 10:33am
Anonymous's picture

Important lesson about the jars... Like people, do not assume they are filled to capacity.

September 16, 2011 - 11:54am
Naomi Karten's picture

Ha! That's a lesson that never even occurred to me. Thanks for highlighting it! ~Naomi

September 24, 2011 - 5:44pm
Naomi Karten's picture

Thanks, Mirkeya. I think the thing that makes this kind of habit so hard to break is that we don't even realize we're acting out of habit. So we have to learn to consciously ask ourselves: might there be another way, and perhaps one that's even better? ~Naomi

September 24, 2011 - 5:43pm
Anonymous's picture

Hi Naomi,

great post and interesting problems.


September 15, 2011 - 4:12pm

About the author

AgileConnection is a TechWell community.

Through conferences, training, consulting, and online resources, TechWell helps you develop and deliver great software every day.