What are mental models?

Mental models are frameworks that give people a representation of how the world works. There are so many mental models that it would take a very long time to study them all in detail. Some are rooted in biological observations, others have been described in behavioral studies.

To put it simply, mental models are a set of beliefs and ideas that we consciously or unconsciously form based on our experiences. They guide our thoughts and behaviours and help us understand life. They’re basically thinking tools—shortcuts for reasoning.

How to build your own mental models

In a fast-moving environment, mental models can be extremely useful to help you think fast and make decisions. After all, they’re great at giving you rules of thumb so you can, if done well, predict likely outcomes or behaviours.

  • Observe people. One great way to develop your own mental models is to find inspiration in people. When you read a biography, ask yourself: why did they make this decision? What were they thinking? What mental model(s) did they use? It doesn’t have to be famous entrepreneurs or creatives. We all have a friend or a colleague whose work we admire. When you see them make a specific choice in a complex situation, ask them how they came to that decision.
  • Take note of nature. Nature follows many rules that can apply to human decision making. For example, the tendency to minimise our energy output can be observed in many natural conditions, and incentives are a key drive in all creatures’ behaviour.
  • Ask for feedback. Ask a friend or a colleague to observe how you act and to help you identify behaviours that may not be obvious to you. This can be an incredibly uncomfortable but mind-expanding exercise.

Don’t limit yourself to constructive mental models. You will observe mental models which you’d rather not reproduce. These are great to study as well, because it’s easier to avoid a thought pattern when you know how to spot it in yourself and others. Constructive or destructive, name your mental models and write them down.

First Principles of Product Management

A first principle is a “basic, foundational proposition or assumption that cannot be deduced from any other proposition or assumption.”.

Second-Order Thinking

Things are not always as they appear. Often when we solve one problem, we end up unintentionally creating another one that’s even worse


Inversion is one of the most powerful, yet simple mental models to uncover things that we normally do not think.

Opportunity Cost

Opportunity costs represent the potential benefits an individual, investor, or business misses out on when choosing one alternative over another. 

Thought experiment

thought experiment is a hypothetical situation in which a hypothesis, theory, or principle is laid out for the purpose of thinking through its consequences.


Leverage is an idea which humans have used to great effect for thousands of years, enabling them to gain disproportionate strength.

Probabilistic Thinking

Probabilistic thinking is essentially trying to estimate, using some tools of math and logic, the likelihood of any specific outcome coming to pass.

Occam’s Razor

Occam’s razor (also called the law of parsimony) is one of the most useful mental models to solve problems


An incentive is something that motivates or drives one to do something or behave in a certain way

5 great books about mental models

If you want to read more about mental models, here are some books to further explore the topic. Not only I found these books useful, but I’ve seen them recommended over and over again on Hacker News and other places.