Psychological Inertia: Two kinds in one story

Ellen Domb, Ph.D.
The TRIZ Institute, 190 N. Mountain Ave., Upland, CA 91786 USA
+1(909)949-0857 FAX +1(909)949-2968

1998, Ellen Domb


The following story is not original. It has been forwarded to me from a variety of Internet lists in the last month. The fact that it is so popular shows the many people are learning many thing from it, but it seemed particulary suitable for this special issue on psychological inertia. The story:

A while back I was reading about an expert on subject of time management. One day this expert was speaking to a group of business students and, to drive home a point, used an illustration those students will never forget.

As this man stood in front of the group of high-powered overachievers he said, "Okay, time for a quiz."

Then he pulled out a one-gallon, wide-mouthed mason jar and set it on a table in front of him. Then he produced about a dozen fist-sized rocks and carefully placed them, one at a time, into the jar. When the jar was filled to the top and no more rocks would fit inside, he asked, "Is this jar full?"

Everyone in the class said, "Yes." Then he said, "Really?" He reached under the table and pulled out a bucket of gravel. Then he dumped some gravel in and shook the jar causing pieces of gravel to work themselves down into the spaces between the big rocks.

Then he asked the group once more, "Is the jar full?"

By this time the class was onto him. "Probably not," one of them answered.

"Good!" he replied. He reached under the table and brought out a bucket of sand. He started dumping the sand in and it went into all the spaces left between the rocks and the gravel. Once more he asked the question, "Is this jar full?"

"No!" the class shouted. Once again he said, "Good!" Then he grabbed a pitcher of water and began to pour it in until the jar was filled to the brim. Then he looked up at the class and asked, "What is the point of this illustration?"

One eager beaver raised his hand and said, "The point is, no matter how full your schedule is, if you try really hard, you can always fit some more things into it!"

"No," the speaker replied, "that's not the point. The truth this illustration teaches us is: If you don't put the big rocks in first, you'll never get them in at all." What are the 'big rocks' in your life? A project that YOU want to accomplish? Time with your loved ones? Your faith, your education, your finances? A cause? Remember to put these BIG ROCKS in first or you'll never get them in at all.

So, tonight or in the morning when you are reflecting on this short story, ask yourself this question: What are the 'big rocks' in my life or business? Then, put those in your jar first.

There are two obvious types of psychological inertia demonstrated:

Authoritariansim: The "expert" (class leader) shows the class that their definition of "full" is faulty, when applied to the large rocks, since he can put more into the jar by applying the TRIZ principle of segmentation (rocks gravel sand water). So the class does not become creative, but it learns to that the "right" answer is that more material can be added to the jar if they use finer and finer divisions of the material. But, they learn this lesson by repeating the experts words, not by doing their own analysis of the situation.

Subject matter specialization: Because the seminar subject is time management, the class jumps to the conclusion that the lesson being taught has to do with how to do more in a finite period of time, making an analogy between finite time available and the finite volume of the jar. They missed the much more important lesson, that big things (rocks, important activities) are hard to fit into a finite limit (the jar, the time available) so you should be creative about how to get the big things done, before you worry about the small things. The title of the class, "Time Management" created a subject matter bias and set up the environment for psychological inertia.


Psychologcial Inertia cartoon:

Psychologist says to patient: "So you think you are in a rut…"

Patient: "NO! A rut goes someplace. I’m in a pothole!"