An Introduction to Mental Models

Mental models put simply are a representation of an external reality inside your head. Wikipedia defines it as:

"A mental model is an explanation of someone's thought process about how something works in the real world. It is a representation of the surrounding world, the relationships between its various parts and a person's intuitive perception about his or her own acts and their consequences. Mental models can help shape behavior and set an approach to solving problems (akin to a personal algorithm) and doing tasks."

So why should we care about mental models? Charles Munger sums it in an address to the USC Business School in 1994:

"What is elementary, worldly wisdom? Well, the first rule is that you can’t really know anything if you just remember isolated facts and try and bang ‘em back. If the facts don’t hang together on a latticework of theory, you don’t have them in a usable form.
You’ve got to have models in your head. And you’ve got to array your experience—both vicarious and direct—on this latticework of models. You may have noticed students who just try to remember and pound back what is remembered. Well, they fail in school and in life. You’ve got to hang experience on a latticework of models in your head.
What are the models? Well, the first rule is that you’ve got to have multiple models—because if you just have one or two that you’re using, the nature of human psychology is such that you’ll torture reality so that it fits your models, or at least you’ll think it does. You become the equivalent of a chiropractor who, of course, is the great boob in medicine.
It’s like the old saying, “To the man with only a hammer, every problem looks like a nail.” And of course, that’s the way the chiropractor goes about practicing medicine. But that’s a perfectly disastrous way to think and a perfectly disastrous way to operate in the world. So you’ve got to have multiple models."

Mental models therefore range from simple generalizations ("people are untrustworthy") through to complex theories (for example Occams Razor, or the Scientific Method). It is important however to realize that they are active - they shape the ways in which we act. 

So in our simple case above, if we naturally believe people are untrustworthy, we would no doubt act very differently than if we intrinsically trusted people. Two people with different mental models can also observe the same event and describe it very differently (in itself a mental model called the Rashomon effect).

When creating my own mental model of mental models, I find that they can be divided into two main areas. The first is behavioral. This is important, especially in a business environment, as it can create negative outcomes in the way we perceive problems or communicate. The second is in personal growth, and how we can learn and apply new mental models to aid in positive decision making.


Behavioral mental models can become a problem primarily through leaps of abstraction. Our minds move at lightning speeds, processing huge amounts of information. But this can often result in causing us to immediately "leap" to generalizations so quickly that we never think to stop and test or interrogate.

In the book the Fifth Discipline by Peter M. Senge, a business world example illustrates this nicely:

"At one firm, many top managers were convinced that "Customers buy products based on price; the quality of service isn't a factor." And it's no wonder they felt that way; customers continually pressed for deeper discounts, and competitors were continually attracting away customers with price promotions. When one marketer who was new to the company urged his superiors to invest in improving service, he was turned down kindly but firmly. The senior leaders never tested the idea, because their leap of abstraction had become "fact" - that "customer don't care about service, customers buy based upon price." They sat and watched while their leading competitor steadily increased its market share by providing a level of service quality that customers had never experienced, and therefore had never asked for."

According to the Fifth Discipline, the problem here is that a mental model has become entrenched and has stifled deeper problem solving:

"The problem with mental models lie not in whether they are right or wrong - by definition, all models are simplifications. The problem with mental models arise when they become implicit - when they exist below the level of our awareness."


Where mental models can help with personal growth is by aiding in good decision making - both within your personal life, and within business.

But what mental models should you learn? I found a good place to start is in the excellent The Decision Book by Mikael Krogerus and Roman Tschappeler (I'll delve deeper into some of these models in later posts). 

In it, they outline the following criteria for good decision making models:

"They simplify: they do not embrace every aspect of reality, but only include those aspects that seem relevant.
They are pragmatic: they focus on what is useful.
They sum up: they are executive summaries of complex interrelations.
They are visual: through images and diagrams, they convey concepts that are difficult to explain in words. 
They organize: they provide structure and crete a filing system.
They are methods: they do not provide answers, they ask questions; answers emerge once you have used the methods, i.e filled them out and worked with them."


Mental models are an important tool to help you to suppress complexity, concentrate on what is important, and develop a framework that can ultimately allow you to ask the right questions and make better decisions.

Can you recognize any mental models that you specifically ascribe to?

Can you recognize any that may be entrenched?

Are there any examples recently where you may have created a 'Leap of Abstraction' without realizing it?

View an evolving list of Mental Models below.