Mastering the Mind: Exploring the Power of Mental Models

Delve into the Power of the Mind: Unlocking Cognitive Mastery. Explore how mental models can supercharge your decision-making and turbocharge problem-solving. Our comprehensive guide on mental models is your passport to the world of effective thinking. Navigate complexities with ease and precision, harnessing the knowledge to shape your destiny. Embark on a journey to sharpen your cognitive toolkit, armed with insights that empower your every choice. Don’t just adapt; thrive in a world filled with challenges. Discover the secrets of thought leaders and visionaries, and become a master of the mental landscape.


Mental models are powerful cognitive tools that help individuals interpret, navigate, and make sense of the world around them. These mental frameworks are constructed from accumulated knowledge, beliefs, and experiences, providing a lens through which we perceive and engage with complex concepts, situations, and decisions.

By employing mental models effectively, individuals can enhance their critical thinking, problem-solving, and decision-making abilities.

Practical Takeaways

  • Diverse Application

  • Enhanced Decision-Making

  • Problem-Solving

  • Expanded Perspective

  • Continuous Learning

  • Effective Communication

  • Adaptation

  • Holistic Thinking

  • Improved Creativity
  • Innovation


  • Versatile Tools

  • Enhanced Thinking

  • Broad Application

  • Improved Understanding

  • Continuous Growth

  • Interconnected Learning

  • Adaptive Thinking

  • Innovative Solutions

  • Conflict Resolution
  • Resource Allocation
  • Goal Achievement
  • Risk Management
  • Interdisciplinary Insights

Notable Quotes


What are mental models? A mental model is an explanation of how something works. The term “mental model” is an overarching term for any kind of concept, framework, or worldview that you carry around in your head.

Mental models help you understand life. For example, supply and demand is a mental model that helps you understand how the economy works. Game theory is a mental model that helps you understand how relationships and trust work. Entropy is a mental model that helps you understand how disorder and decay work.

Mental models also guide your perception and behavior. They are the thinking tools you use to understand life, make decisions, and solve problems. Learning a new mental model gives you a new way of seeing the world – like Richard Feynman, who learned a new mathematical technique.

Mental models are imperfect, but useful. For example, there is no single mental model from physics or engineering that explains the entire universe flawlessly, but the best mental models from these disciplines have allowed us to build bridges and roads, develop new technologies, and even travel into space. As historian Yuval Noah Harari puts it, “Scientists generally agree that no theory is 100 percent correct. The true test of knowledge, then, is not truth, but utility.

The best mental models are the ideas with the greatest utility. They are of great use in daily life. When you understand these concepts, you can make smarter decisions and act better. That’s why developing a broad base of mental models is critical for anyone who wants to think clearly, rationally, and effectively.

Mental Models in Economics and Strategy

Opportunity Cost

What you are willing to sacrifice in order to do something else. The goal is to minimize the cost. Opportunity costs are real.

The time value of money is a central concept in economics. It means that today’s money is worth more than tomorrow’s money. This relationship is purely based on the opportunity costs.

Creative Destruction

Creative destruction, also known as Schumpeter’s gale after Austrian economist Joseph Schumpeter is a theory that explains economic innovation in a free market economy. This refers to the constant innovation of products and processes that replaces outdated production units or those without innovation.

The absence of innovation in a capitalistic environment does not lead to stagnation. It leads to decay.

Primary Source: Joseph Schumpeter

Double Entry Bookkeeping

Luca Pacioli published the first book about double-entry accounting in Genoa, 1494. Since then, the method of balancing books using two accounts per entry has not changed.

Accounting’s dualistic view of the world can be a powerful tool for understanding economic and social events.

Primary Source: Luca Pacioli

Comparative advantage

David Ricardo, a Scottish economist, found that, as a model for international trade theory, all parties can benefit from voluntary trade and cooperation if they focus on their comparative strengths in terms of the opportunity cost.

Comparative advantage is held by the party that has the lowest opportunity cost to produce a good or a service and, therefore, the smallest possible loss of benefit.

Primary Source: David Ricardo


A method of generating income (economic rent) by exploiting others, rather than creating value. An example would be to use resources for political lobbying in order to promote legislation that is in one’s best interests.

Primary Source: David Ricardo

Switching cost

The costs of switching sellers or the disadvantages that a buyer faces.

Nash Equilibrium

After evaluating the rational choices and strategies of their opponents, two or more players in a noncooperative game will not be tempted to change their equilibrium strategies.

The model, named after John Nash the mathematician, proves that sometimes decisions that are good or individuals can be bad for groups.

Primary source: John Nash

Model AD-AS Model

The AD-AS model, based on John Maynard Keynes’ general theory of economics, explains prices and national income by examining the relationship between aggregate demand and supply. It’s a powerful tool when it comes to macroeconomic effects on the short, medium and long-term.

The model can accommodate Keynes’s Law, which is based on aggregate demand in the short term, as well as Say’s Law, which is based on aggregate supply over the long run.

Controlling Centre

The centre provides more flexibility and mobility in comparison to the competitor. If you let your opponent take control of the centre squares in chess, they will enjoy a much easier game. To control the central square, a piece doesn’t have to be physically on that square. The bishop, for example, can control the central square from afar.

Controlling the middle of a value-chain can be incredibly profitable in business. Brokerage firms and internet marketplaces like Alibaba are examples of business models.


Specialization, also known as division of labor or specialization of skill sets, is the process whereby participants in a market-based system are divided into different skill sets to improve efficiency. The whole system gains from increasing productivity in each area of specialization.

Primary Source: Adam Smith

Intellectual Property

Intellectual property rights have been an important catalyst for societal creativity. These rights cover intangible works of human intellect. Some countries recognize more types than others. Copyrights are the most common, followed by trademarks and trade secrets. These rights can be used by individuals and companies to create economic moats that are defended against their competitors. This model is extremely powerful as long as capital expenditures and ongoing research and developments can be managed.

It seems that very few economic moats, if any at all, are based on intellectual property. They are either expiring or become obsolete because of societal progress and destruction. They can be very durable.

Mental Models in Human Nature and Judgment


Trust plays a major role in human behaviour and affects everything we do. Trust increases speed and efficiency, improves ethical decision-making, and reduces costs.

Heuristic for Availability

It is a tendency to measure the frequency of world events by how easily you can recall examples. We are more likely to remember what is important, recent, salient and frequent. We make decisions based upon what we can most readily recall, but it is not accurate to judge the frequency and magnitude.

Primary source: Daniel Kahneman and Amos Tversky


It is a tendency to make subsequent decisions based on a piece of initial information. Anchoring cognitive bias is closely linked to the availability heuristic, since the mind anchors on what is familiar.

Primary source: Daniel Kahneman and Amos Tversky


It is a social norm to respond positively to an action that was positive, even when the original action was not desired. It is interesting to note that positive actions are often bigger than the original action.

Primary Source: Robert Cialdini

Envy and Jealousy

In an interconnected, globalized world, it is difficult to avoid envy. Human nature has been influenced by envy since ancient times. Even though the Stoics warned of the dangers of envy, it is still deeply ingrained into human nature. Warren Buffett said: Envy is what drives the world.


Denial has a powerful effect on the mind. Denial distorts reality until it is bearable. Refusing to accept truth or reality is a primitive survival or defence mechanism.


Situations that cause a biological reaction when faced with a significant challenge or perceiving a threat. Stress activates the fight-or flight response, which dates back to hunter-gatherer times.

Yerkes Dodson Law states that performance is increased by anxiety and excitement but only up to a certain point.

Social Proof

Researchers arranged for an individual to cross the road against the red light and into the traffic in a study. In half of the cases, he wore a suit and tie. He wore trousers and a shirt for the other half. In the study, it was found that when the man wore a suit, three times more pedestrians were swept into traffic against the light and against the law.

Robert Cialdini coined the term social proof to describe a powerful phenomenon in which people assume others’ actions and try to mimic them.

Primary Source: Robert Cialdini


If the options presented have a positive or negative connotation, it can influence your decision and determine what you do. Framing, when combined with the narrative fallacy can lead to errors in decision-making and be used by others as a way of controlling their behaviour.

Primary source Daniel Kahneman and Amos Tversky

Mental Accounting

A tendency to divide the money into separate pots, and then treat each one separately according to subjective criteria. Richard Thaler says that people tend to think in terms of relative value rather than absolute value. They are not only interested in the value of an item, but also its utility – the transactional quality. This phenomenon explains why people will spend more money when paying with credit cards than cash.

Primary Source: Richard Thaler

Pavlovian Association

Ivan Pavlov’s learning method of pairing a stimulus and a conditioned reaction. Pavlov’s experiment with his dogs demonstrated how a bowl of food and a ringing bell (stimulus), would trigger an unconditioned reaction (salivation). Pavlov noticed that his dogs began to associate food with his lab assistant, creating an unconditioned response (salivation).

Primary Source: Ivan Pavlov

Operational Conditioning

The use of rewards and punishment to teach. These methods can be used in a variety of natural settings, as well as more structured settings like the classroom or therapy sessions.

Primary source B. F. Skinner

Commitment and Consistency Bias

Consistency bias is a tendency to follow through on previous actions. The commitment and consistency bias are a result of the fact that human actions, beliefs and commitments are important in forming self-perception. This makes it difficult to change an action course once chosen, even if someone else has forced you to do so.

Primary Source: Robert Cialdini

Sunk Cost Fallacy

The sunk costs fallacy, which is closely related to the anchoring bias and the commitment biases, is the tendency to persist in an undertaking despite the resources and efforts invested even if it seems like a good idea to stop. Researchers have found that humans, rats, and mice are all sensitive to the sunk cost fallacy after deciding to pursue a particular reward.

Liking Tendency

Robert Cialdini says: “It’s not surprising that people are more likely to accept a request if they like and know the person making it.” Discovering genuine parallels or similarities between you and someone you wish to influence is a simple way to get things moving in your favour. This increases the rapport.

Primary Source: Robert Cialdini


A tendency to generalize too much about a group or population. This concept is closely linked to the availability heuristic.


A group’s desire to achieve harmony, compromise, and conformity can lead to irrational decisions, even if the goal of the group was the opposite.

Primary Source: William H. Whyte Jr.

Authority Bias

It is a tendency in human behaviour to give greater weight to someone’s opinion who has authority. It can happen even if the individual thinks that following authority is wrong and there would be no penalty for disobeying it.

Stanley Milgram was a Yale University professor of psychology who conducted the now famous Milgram experiment in 1961. Participants were instructed to administer painful electric shocks, which could be harmful to another individual they couldn’t see. They did it even though they knew that they were doing something wrong and wanted to stop, because they felt compelled by the authority of the person conducting the experiment.

Primary Source: Stanley Milgram

First-Conclusion Bias

The tendency to stick with the first conclusion or information that is presented for a problem and to resist the need to explore other options.

Confirmation Bias

A tendency to interpret situations or look for evidence that supports pre-existing views. Charles Darwin was said to have not been able come up with his theory of evolution if he hadn’t constantly destroyed confirmation bias from his studies. He was always looking for and noting observations that contradicted his beliefs and making an effort to investigate these.

Hindsight Bias

It’s also known as creeping determinism. This is the tendency to overestimate one’s ability of predicting an outcome which could not have been predicted. It is dangerous to have a hindsight bias because it prevents you from learning from your mistakes. We won’t examine the real reasons for something if we think we already knew what happened.

Survivorship Bias

This is a form of bias in which the data illuminated by the survivors, or the subjects are evaluated disproportionately.

It is a widely held belief that equipment, machinery, and other goods produced in the past are often better made and last longer than similar items manufactured today. You often hear people say that they don’t build ’em the way they used to. It is inevitable, however, that only the items built to last have survived.

Curse of Knowledge

We find it difficult, once we have learned something, to imagine how it would be to not know it. It is also hard to see problems through the eyes of someone who has less knowledge. It becomes more difficult to explain an idea clearly and simply the more you learn about a topic. Knowledge itself can be a barrier in its own propagation.

Primary Source: Colin Camerer, George Loewenstein, Martin Weber

Reductive Bias

It is important to treat complex non-linear systems as though they were linear. The mismatch between the complexity of reality and the mental routines used to simplify it is the main cause of mistakes.

Bias Caused by Incentive

Incentives are a powerful tool to motivate people. Someone who pays someone to be irresponsible is more likely to act irresponsibly. You will usually get the result that you reward. You need to be careful how you create your rewards.

Representativeness Heuristic

Linda is a 31-year-old woman who is bright, single and outspoken. She studied philosophy at university. She was deeply concerned about issues of social injustice and discrimination as a student.

Laura working at a Bank is more likely? Is it more likely she is a feminist activist and works in a bank?

The last option can lead to the representativeness heuristic, which is the tendency to confuse the likelihood of a result by comparing similar objects or events. The possibility that Linda works at a banking is higher because it is part of a larger category.

Primary source: Daniel Kahneman and Amos Tversky

Narrative Instinct

Stories are incredibly powerful because we tend to understand the world by analysing cause and effect. You can imagine what kinds of errors could be caused by this. Remember the story of Linda from the previous model of representativeness.

Bizarreness Effect

It is easier to remember information that is unusual or controversial than something common.

Baader-Meinhof phenomenon

This phenomenon, also known as the frequency illusion, is an illusion in which something that has been brought to your attention recently suddenly appears with an improbable amount of frequency soon afterward. You are then led to overestimate how common it really is. This phenomenon is closely related to the selection and recency bias.

Cobra Effect

The British government, during the colonial rule in India, was worried about the number of cobras that were venomous. They offered a reward for each dead cobra. Initially, the policy appeared to be successful. Over time, however, it became apparent that cobras were being bred to earn money. The government was made aware of the situation and the program was scrapped. This caused the cobra-breeders to release their snakes, which were now worthless. The wild cobra population increased as a result. The apparent solution made the problem worse.

The Cobra Effect is the result of a solution that makes the problem worse. Often, the root cause of a problem is a linear approach to solving it. This ignores the effects of feedback loops. The model shows how simplistic policies can backfire.

Boomerang Effect

Unintended consequences of people being convinced to do something, but then doing the opposite. The boomerang effect, also known as the psychological reactance theory, occurs when people perceive someone is trying to limit their freedom.

Curiosity Instinct

Curiosity is the key to exploration, learning, and investigation. Science and technology wouldn’t exist without the curiosity of humans. Without curiosity, companies cannot survive.

Language Instinct

The ability to speak is a natural human trait. This shows our cognitive structure. Steven Pinker believes that language is a human ability, created by evolution in order to solve the problem of social communication between hunter-gatherers.

Steven Pinker, primary source

Hasty Generalization

The human mind is prone to stereotypes and tends to generalize from general rules derived from a small sample of data. Sometimes, however, when the data do not match the population’s characteristics, this can lead to an overgeneralization. Daniel Kahneman says: Extreme outcomes (both low and high) are more likely in small samples than large samples. This is not a causal explanation.

Relative Satisfaction

A tendency to compare one’s circumstances with those of others to assess how satisfied you are. The relative level of satisfaction is a major cause of jealousy and envy. Charlie Munger once said that envy is the stupidest sin, because you can’t have fun with it.

Kantian Fairness Tendency

Emmanual Kant’s ethical theory of justice requires that an action be permissible if it can be applied to everyone without contradiction.

Humans are strongly drawn to the concept of fairness. Life isn’t always fair, and many people can’t accept that. It’s okay to tolerate a little injustice if it leads to greater fairness. Balance is important, but it’s not life.

Fundamental Attribution Error

It is the tendency to focus on personal traits and ignore contextual factors when judging other people’s actions and behaviours. This leads to the belief that people’s actions and behaviour reflect their personality.

Imagine that Alice, a motorist, is cut-off in traffic by Bob. Alice immediately attributes Bob’s behaviour to his basic personality, for example. He’s a selfish driver and an incompetent one. She doesn’t immediately consider the possibility that Bob could be late for his flight, his son’s birth or an accident. Alice could make the opposite error and say that she was influenced in some way by the situation. Actor-observer symmetry is another name for this.

Primary Source: Lee Ross

Action Bias

Humans have a tendency not to wait and watch. They will act, even if no action is required. Sometimes it’s best to just watch the grass grow.

Principle of Minimum Effort

The theory that humans, animals and machines that are well-designed will seek the path that is least resistant and that their effort will decrease as soon as they achieve the minimum result.

Primary Source: Guillaume Ferrero

Cognitive Dissonance

Cognitive dissonance is the result of trying to simultaneously believe two things that are incompatible. Cognitive dissonance occurs when people smoke despite knowing that it is bad for them.

Primary Source: Leon Festinger

Hard-Easy effect

We tend to underestimate our abilities to do things easy and overestimate them. We tend to overestimate our ability to do something difficult and underestimate our ability to do something easy. This is related to the Dunning Kruger effect.

Primary Source: Leon Festinger

Focusing Effect

It is the tendency to place too much importance on small factors which are not important in the context of a bigger system. It’s the tendency to not see the forest through the trees. Daniel Kahneman said that nothing in life is as significant as you think you are when you are thinking it.


It is a tendency to weight recent information more than older information, even though the latter may be less important. It is closely related to availability heuristic.

Planning Fallacy

Tasks take longer than anticipated. The planning fallacy was first proposed by Daniel Kahneman in 1979. It is an effect on optimism bias that describes not only underestimating time, but also costs and risks.

Primary source: Daniel Kahneman and Amos Tversky

Reputation Fragility

Warren Buffett said: It takes twenty years to build up a good reputation, and five minutes to ruin one.

Noise Bottleneck

Nassim Taleb coined the term noise bottleneck to describe the situation whereby more sampling decreases the signal to noise ratio, increasing randomness and decreasing the likelihood of sound conclusions. It is natural to believe that more information will be better, except when it leads us to focus on irrelevant data.

Primary Source: Nassim Talab

Keynesian Beauty Contest

A Keynesian beauty competition is closely related to the parimutuel system. It is used to describe a type of action based on an assumption of the public’s perception of a topic. It is possible to go one step further and take into consideration that each entrant will have their own perception of public perceptions. The strategy can then be applied to the next level and beyond, attempting to predict what the final outcome will be based on other rational agents’ reasoning.

John Maynard Keynes illustrated this with an analogy that was based on the fictional newspaper contest where contestants had to pick six of the most attractive faces out of a hundred photos. The winner was the person who chose the most popular face.

Keynes argued that it was not possible to choose the [faces] which, in one’s opinion, are the most beautiful, or even the ones that the average opinion thinks of as the most beautiful. In the third degree, we use our intelligence to predict what the average opinion will be. There are, I think, some who practice the fifth and higher degrees.

Primary source: John Maynard Keynes

Serpico Effect

The Serpico Effect is named after Frank Serpico who was known for his whistleblowing about police corruption during the 1960s and 1970s. It is the tendency of rationalizing an action just because others are doing it.

Depressive Realism

Hypothesis stating that people who are depressed make more realistic conclusions than people who are not depressed. The opposite of blissfully unaware. Depressive realism can be a useful mental tool, but the evidence is still largely debated.

Primary Source: Lauren Alloy, Lyn Yvonne Abramson

Skill Compensation

People who are good at something may be poor at another. A result of deciding to spend more time on one skill than another.

Compassion Face

Small groups tend to show more compassion towards victims than large groups. This is because it’s easier to identify victims in smaller groups. We can be moved by a single victim, while a larger group seems more distant.

Three men make a Tiger

Chinese proverb which highlights the tendency of people to accept ridiculous information if it’s repeated by enough people. You might think that if one person says there is a tiger in town, they are lying. You start to doubt if two people say it. You’re more likely to believe it if three people say it is true.

Primary Source: Pang Cong

Buridan Ass

Buridan’s ass, named after French philosopher Jean Buridan is a form of decision paralysis in which two options that are equally good lead to no decisions.

The paradox can be explained by a story about a donkey who is both hungry and thirsty, and is placed exactly in the middle of a pile of hay or a pail filled with water. The paradox assumes that the donkey always chooses the option closest to it, so it will die of both hunger as well as thirst because it can’t make a rational decision.

Jean Buridan, primary source

Imposter Syndrome

Fear of being perceived as less talented by others. Impostorism is the term used to describe the feeling that one does not deserve what they have accomplished.

Primary source: Pauline R. Clance and Suzanne A. Imes

Semmelweis Effect

Semmelweis Reflex is similar to the first-conclusion bias. It is the tendency to reject any new information or evidence that contradicts existing norms, beliefs or paradigms. The Semmelweis reflex is named after Ignaz Semmelweis, a Hungarian physician who found that doctors who wash their hand before treating patients get less infections. However, he struggled to convince other people that this was true.

Primary source Ignaz Semmelweis

False-Consensus Effect

This is the tendency to falsely believe that your beliefs or views are held by a larger population than they actually are. This false consensus can increase or decrease self-esteem or cause an overconfidence effect. Relationship to the curse.

McNamara Fallacy

It’s named after Robert McNamara who was the US Secretary for Defense during the Vietnam War. The belief is that rational decisions should only be made on the basis quantitative evidence and ignore all other factors. McNamara based his assessment of success in the Vietnam War solely on enemy body counts. This led the US Army to lose sight of its strategic goals. Do not assume that something which cannot be measured is not important.

Courtesy Bias

A refusal to give an honest opinion because of a desire to not offend the person responding. Employees are often reluctant to give their honest opinions to superiors. This impedes the flow of information for rational decision-making in a company.

Lucid Fallacy

The ludic Fallacy, identified by Nassim Talib and described in The Black Swan is the tendency of falsely associating simulations with reality. Simulations, which are “narrow worlds” of dice and game, fail to take into account the chaos that can occur in real life.

Primary Source: Nassim Talab

Dunning-Kruger Effect

This cognitive bias is observed in people who have a low level of competence and tend to underestimate their own abilities. This effect was documented and named by psychologists David Dunning & Justin Kruger. It is explained by the lack of ability to identify one’s limits at this level. Intelligence is required to know the limits of your intelligence.

Primary source: David dunning and Justin Kruger

Abilene Paradox

A group that decides on a course of action contrary to the feelings and thoughts of the individual members. This happens when members of a group fail to communicate their personal beliefs.

Primary source: Jerry B. Harvey

In-group Favouritism

In-group favouritism, which is closely related to liking tendencies, is the tendency to give priority to members of your own social circle. Nepotism, for example, is an example.

Primary Source: William Sumner

Collective Narcissism

Exaggerating the positive image or importance of a group to which one belongs.

Primary source Sigmund Fréud

Normalcy Bias

It is common to think that threats and disasters will never happen because we believe things will continue as before.

Texas Sharpshooter Fallacy

It is the act of selecting the target after the shot to make it impossible to miss. The same data can be used to test and construct a hypothesis. This leads to incorrect conclusions.

Plain Folks Fallacy

The speaker tries to convince the audience that their ideas and themselves are “of people”.

Poisoning of the Well

It’s also called a smear technique. This is the act of presenting irrelevant negative information before an argument. It makes that person or argument seem untrustworthy. Please remember that before you listen to his words, he was in prison.

Primary Source: John Henry Newman

Appeal to Consequences

Argument that attempts to prove the truth or falsity of a hypothesis because its consequences are either desirable or unwelcome. It’s a fallacy.

Behavioural Inevitability

Human behaviour and its inherent biases will never change. As Voltaire said: History never repeats itself; man, always does.


A tendency to avoid doing something out of fear that it will damage one’s self esteem.

Primary source Edward E. Jones and Steven Berglas

False Uniqueness Effect

A cognitive attributional error is when one assumes that their qualities, traits and personal attributes are unique, but they aren’t. It’s the exact opposite of imposter Syndrome.

Backfiring Effect

When presented with evidence that contradicts one’s beliefs, people tend to reinforce them. In a study of political voting, it was found that when people were given negative information about a candidate they liked, their support increased.

Positive Illusions

Self-deception in which individuals exaggerate their own abilities, decisions and self-esteem to avoid discomfort or boost self-esteem. A positive illusion can cause a downward spiral of justifying worse and worse choices.

Primary source Shelley Taylor and Jonathon Brown

Ironic Process Theory

Psychological process that involves suppressing certain thoughts in order to make them more likely to return to one’s mind.

Primary Source: Daniel Wegner

Aumann’s agreement Theorem

The Aumann Principle, named after the Israeli-American mathematician Robert Aumann is the idea that two rational people who are in a conflicting argument cannot and should not agree to disagree when they know each other’s beliefs.

Primary Source: Robert Aumann

Ostrich Effect

The ostrich effect occurs when people avoid information that contradicts what they want to be true.

Primary Source: Dan Galai and Orly Sade

Bounded Rationality

The human mind is limited in its capacity to retain and recall information, so rationality also has limitations.

Primary Source: Herbert Simon

Fluency Heuristic

Fluency Heuristic, also known as the narrative fallacy is the tendency to trust ideas that are easier to understand than those that require more explanation.

Persian Messenger Syndrome

Blaming someone for bad news.

Charlie Munger said that the Persians did indeed kill the messengers who brought bad news. You think it’s dead? You should have seen Bill Paley’s last 20 years. He never heard a word he did not want to hear. Bill Paley was not happy to hear anything. This means the leader is in a cocoon, and he has made some very stupid decisions over the past 20 years.

Okrent’s law

Daniel Okrent, a writer, referred to a phenomenon whereby the media legitimizes fringe views that are not supported in order to appear fair.

He said that the pursuit of balance could create imbalance, because sometimes things are true.

Primary Source: Daniel Okrent

Vierordt’s Law

The German physiologist Karl von Vierordt formulated this law in 1868. It states that people perceive time differently over a range of durations. We tend to underestimate long time periods and overestimate shorter ones.

Primary source: Karl von Vierordt

Cunningham’s Law

Ward Cunningham said that the best way to find the answer on the Internet was not to ask questions. Posting the wrong answer is what’s most likely to get you an incorrect answer.

When you’re in front of an audience, you can get a different reaction. Outrage can elevate your status.

Internet rage is similar to road rage. Once you argue with a vehicle (or computer) instead of a person, the social norms disappear.

Primary source: Ward Cunningham

Tyranny of small decisions

Situation in which a series small, rational decisions can create a dependency on a particular path. This dependence could negatively affect the context of subsequent decisions to the point that the original desire becomes irreversibly destroyed.

Primary source Alfred Kahn

Hyperbolic Discounts

The tendency to prefer rewards that come sooner than later. Humans discount future events. Interest rates are a result of this.

Primary Source: Richard Herrnstein

Delayed Gratification

A person’s process of avoiding immediate rewards in favor of a reward that will come later.

Observer Effect

Situations where an individual is observed but that observation changes the individual’s behaviour. Simply observing something will change it.

Golem Effect

Performance tends to decrease when teachers, supervisors or bosses are low on expectations.

Maslow’s Hierarchy of Needs

Motivational theory developed by Abraham Maslow, in 1943, that states humans have five different categories of needs: physiological, love, safety, esteem and self-actualization. When the previous need has been met, higher needs will appear in the hierarchy.

Primary source Abraham Maslow

Bystander Effect

Social observation: People are less likely than usual to assist a victim if others are in the room. The more bystanders there are, the less likely it is that someone will assist.

Primary Source: John M. Darley, Bibb Latane

Hot Hand Fallacy

The expectation that an event that was preceded by the consequences of a previous event will happen. A streak of successful shots can lead sports fans to believe that the probability of a player making the next shot is higher.

Primary source Amos Tversky, Thomas Gilovich, Robert Vallone

The Gambler’s Fallacy

It’s also known as the Monte Carlo Fallacy. This is the incorrect belief that a series of specific results from a random process will make it less or greater likely to happen the next time.

A series of 10 coin tosses might result in all heads. A gambler might believe that the next coin toss will be more likely to end in tails.

Primary source: Daniel Kahneman and Amos Tversky

Acton’s law

Absolute power corrupts absolutely.

Primary Source: John Dalberg Acton

Brandolini’s law

It takes a lot more energy to make bullshit than it does to destroy it.

Primary Source: Alberto Brandolini is an Italian programmer

Peltzman Law

When security measures are mandated, people will engage in more risky behaviors.

Primary Source: Sam Peltzman

Power Laws

When an absolute change in one quantity leads to a proportional change in another quantity. Most empirical distributions do not follow a Power Law for all values, but instead follow one in the tail. 

In a market-based economy, for example, income distribution follows a power law since inequality is built in to the wealth accumulation process itself. People in big cities attract more people. Capital in corporations attracts additional capital. Profits lead to more profit. Pareto is a power law.

Permutations and Combinations

We care about the order in which the elements are arranged, but not with combinations. Permutations and combination mathematics is extremely important because it helps us understand the probabilities in the real world.

Primary source: Blaise Pascal; Pierre de Fermat


The manipulation and study of mathematical symbols to show equivalence between subjects. Algebra is an important part of all studies in mathematics, science or engineering as well as applications such as medicine and economy.

Multiplying by Zero

No matter how big the number is, it will always become zero when multiplied by 0. This is a lesson that’s often only learned through hard experience. It’s dangerous to multiply your capital zero when trying to compound returns.


The world is full of randomness, but we often don’t understand it. A mistaken search for patterns can lead us to see patterns that do not exist. Nassim taleb says that we are “fooled” by randomness.

Stochastic Processes

A group of random variables in the same probability space. Brownian motion, random walk theory and stochastic processes are all stochastic processes.

The Gambler’s Ruin

A persistently playing a game with a low probability will lead to bankruptcy. The gambler’s ruin could also explain why a player goes broke despite having a positive expectation value for each bet. The gambler will lose money if he raises his bet to a certain fraction of their bankroll after winning but does not reduce it after losing.

Primary source: Blaise Pascal; Pierre de Fermat


When interest is added regularly to the amount that earned interest, it creates a powerful force. Albert Einstein called it the “8th Wonder of the World”. It’s a mathematical idea that is the foundation of the finance field, but not limited to finance. Compound interest is the foundation for knowledge, ability, ideas, relationships and more. Naval Ravikant said: Play iterated or repeated games. Compound interest is the key to all returns, be it in wealth, knowledge, or relationships.

Compounding is a long-term process, so it’s important to understand the time value. Short-term gains can be hard to notice.


Entropy is another name for churn. It’s a measure of how many people or things leave a group in a certain time period (think of customers of subscription services or insurance companies). To reduce churn, the group must be constantly cared for.

The churn rate and growth rate are diametrically opposite factors. One measures the loss of the group, and the other measures the acquisition into the group.

Law of Large Numbers

The law states that the average result of a large number events should be near the expected value and tends to get closer as more events happen. The Swiss mathematician Jakob Bernoulli proved it in 1713.

The law of large number is apparent in business when comparing growth rates expressed as percentages. The percentage growth rate becomes more difficult to maintain as a company grows.

Probability Distributions

The statistical functions describe the probabilities and values that a random variate can have within a range. The standard deviation, skewness and kurtosis of the distribution will determine how it is arranged. This is most commonly found in science, finance, and engineering.

The Central Limit Theorem

The sum of a number of independent random variable, with probabilities that may differ, but have finite variances will tend to a normal distribution.

Primary source Pierre-Simon Laplace

Confidence Interval

This is the measure of how well a sample estimate can explain the true value when it’s tested on a large population. The range of values in which we can be reasonably certain that our true value is located. Financial problems are often caused by a lack of understanding of the confidence interval.

Regression to Mean

This is what happens when many observations follow the Law of Large Numbers. Regression to the Mean is a statistical concept that suggests that if a random variable has extreme values on the first measurement, it will have fewer extremes on subsequent measurements.

The concept is easy to grasp. It’s easy to understand, but not knowing its limits or when it applies can be very dangerous. In the stock market, for example, huge amounts of money were lost by buying companies with a price-to book ratio below average in the mistaken belief that their value would follow the regression principle. The investor may not realize that the price of the stock is only the numerator, and the book value is the denominator.

Order of Magnitude

Quantitative measure used for very approximate comparisons. Two numbers that differ by an order of magnitude are about ten times bigger than each other.

Kelly Criterion

John Larry Kelly Jr., a scientist at Bell Labs in 1956, developed a formula to determine the optimal size of bets based on odds and the edge of the player. The formula was based on Claude Shannon’s information theory and Bernoulli’s St. Petersburg Paradox.

The formula is:

Edge or odds = Fractional part of your bankroll that you bet every time

The Kelly criterion, for example, suggests that a positive risk/reward wager of 1:2, with 50% odds of either outcome is the best bet size. (Reward, in the event of positive odds, is 2, and edge is 0, so 0.5/2 = 25%). The Kelly criterion is the only way to increase wealth without risking the bankroll.

Primary Source: John Larry Kelly Jr.


A curve that initially drops, but then rises steeply above its starting point.

This model is used to analyze the trajectory of a country’s terms of trading following a devaluation, or depreciation, of its currency under certain conditions.

The J-curve in private equity is used to show the tendency for private equity funds in the early years to have negative returns and then to see investment gains as portfolios mature.

Neglect of Base Rate

It is a tendency to give more weight to appealing information in an individual’s situation and ignore the a posteriori probability. My son is one of the 6% who get into this school. He’s brilliant. I’m confident they will accept him.

Primary source Daniel Kahneman and Amos Tversky

Anscombe Quartet

Anscombe’s quartet, developed by statistician Francis Anscombe is when seemingly identical numbers don’t look the same when plotted. Graphs are not as precise as numerical calculations.

Primary Source: Francis Anscombe

Selection Bias

A statistical error that occurs when a sample of data is not representative for the entire population.

Berkson Paradox

This is a case in which conditional probabilities and correlations seem counterintuitive because of a bias due to sampling or selection.

Imagine a stamp collection of 1000 stamps. 300 are beautiful and 100 are rare. 30 are both beautiful and rare. The rarity of stamps is not determined by their beauty. Only 10% of stamps collected by collectors are rare.

Primary Source: Joseph Berkson


Psychological phenomenon in which random and meaningless impressions can be perceived as meaningful. This is a way of comforting the mind by explaining how the universe works. Patternicity is the ability to see patterns or connections where none exist.

Source: Klaus Conrad

Neglecting Probability

In uncertain situations, the tendency to ignore probability when making decisions. Small risks are either completely ignored or vastly overrated. The tendency to ignore probability can lead to hindsight bias.


Ergodicity, which is a concept that comes from thermodynamics and the study of population dynamics, describes a situation whereby individual events are not affected by the population’s probabilities but rather become more even over time. Russian roulette is a game that can be played many times without dying.

Primary source Ludwig Boltzmann

Moral Luck

Praise for an act that a person did not have complete control over. Nassim Taleb says: “Avoid calling heroes those who were forced to do it.”

Primary Source: Bernard Williams

Friendship Paradox

The average person has fewer friends than the friends they have. It is due to a sampling bias, where people who have more friends are likelier to be your friend. The friendship paradox is a contradiction, because people tend to believe they have more close friends than their closest friends.

Primary Source: Scott L. Feld

Clustering Illusions

Assuming falsely that clusters or streaks of small samples within a large data pool in random distributions indicates a non-random pattern.

Primary Source: Thomas Gilovich


Nonlinearity, closely related to the Kantian fairness trend, is a situation in which there is no straight-line relationship or direct relation between an independent variable (or variables) and a dependent one. The output does not match the change in the input. This can sometimes make the situation appear chaotic, unpredictable or counterintuitive. Understanding this topic is very important.


Situations where the relationship between variables is dependent on a third factor. A third variable, glue, could be the reason why two objects stick together thickly and thinly.

Denomination Effect

We tend to think that 10 $5 bills are less valuable than a single $50 bill, even though they have the same value. Stock splits also show the denomination effect.

Primary source Priya Raghubir and Joydeep Srivastava

Woozle Effect

It is a form of deception when people are misled into believing that information they have heard before, but which lacks any evidence, is actually evidence. Daniel Kahneman says: Repetition is a reliable way to get people to believe falsehoods, since familiarity cannot be distinguished from truth.

The Scientific Method

A method for acquiring knowledge by systematic observation, measurement and experimentation, as well as the formulation, testing and modification of hypotheses.


A variable that replaces an unmeasurable variable. To be a good substitute, the proxy value must be very close to that of the original.

Inflection point

The point at which a curve goes from concave to convex, or vice versa.

Simpson’s Paradox

When a trend is evident on different data groups but not when the groups are combined.

Primary Source: Edward H. Simpson

Surface Area

The space outside a solid. The amount of steel needed to build a larger tank can hold more. This is a nonlinear relationship.

Maxima and Minima

Maxima and minima, also known as extrema or extremes, are the highest and the lowest values in a given function. Pierre de Fermat, one of the earliest mathematicians, proposed a technique called adequacy for finding maxima and minima in functions.

Sensitivity Analysis

Method of assessing stability of research findings by changing the conditions of each variable.

Benford’s law

This law describes how different numbers are distributed in statistics as the first figure. Benford’s Law states, for example, that the first number should be 1 in 30,1% of cases, 2 in 17,6%, and 9 in 4,6% in very large amounts of data.

Frank Benford, primary source

Black Swan Events

Rare events with a big impact are hard to predict, and beyond the normal estimations.

Primary source Nassim Taleb

Goodhart’s Law

A measure that becomes a goal is no longer a good one. If we have a specific goal in mind, then people tend to maximize that goal regardless of any consequences.

Charles Goodhart: economist

Mental Models of Thinking

Decision Trees

A visual representation of the chain of events that leads from one action to another. Decision trees are the basis of many algorithms.

Probabilistic Thinking

Probability is the rule of the universe, so adopting probabilistic thinking as a skill and trait is essential. John Maynard Keynes said that it’s better to get things right in the middle than be completely wrong.

Second-Order Thought

Think about effects and their effects. Second-order thinkers are those who ask, “And then what?”

Second-order reasoning is closely related to the use of decision trees and permutations. It is important in the investment industry. Ray Dalio said: Failure to consider second- and third order consequences is a cause of many painfully bad choices. It is particularly deadly when your first inferior option confirms you own biases.

Bayesian Update

Method of updating the probability estimate for a hypotheses as new information or evidence becomes available. Bayesian updating closely relates to subjective probabilities, which is why it’s in tune with the way things work. The Reverend Thomas Bayes was the inspiration for its name.

Primary Source: Thomas Bayes

Bloom’s Taxonomy

Bloom’s Taxonomy, created by Benjamin Bloom in the year 1956, is a hierarchy of three levels of thought about any subject. The taxonomy is divided into three domains of learning: cognitive, affective and psychomotor. Each domain has a hierarchy of levels, where each level includes the previous levels.

The cognitive domains can be categorized as follows: knowledge, understanding, application, analyzation, synthesis and evaluation.

Primary source: Benjamin Bloom

Circle of Competence

Blind spots can occur when one moves outside of their circle of competence. When one cannot define or even think about their circle of expertise, they often feel the same level of confidence that one feels when operating within it. This is dangerous.

This concept is crucial because it allows people with limited but valuable insights to compete in a world of intense competition against other bright and hardworking people.

Warren Buffett as the primary source

First Principles

Basic assumptions in a field that cannot be further deduced. Aristotle described first principles as the basis on which something is known. It is the idea that complex problems can be broken down into their simplest and most essential elements.

Primary source Aristotle

Think Experiment

A hypothetical experiment is used to solve problems with potential consequences. Einstein used this concept to develop the theory of relativity. He imagined traveling on a light beam.


Reverse thinking is a way to find the core of a problem. Carl Gustav Jacob Jacobi taught his students to always invert their research topics when they are looking for ideas.

Primary Source: Carl Gustav Jacob Jacobi

Five reasons why you should buy a new car

You can find out the truth by asking yourself five whys.

Primary Source: Sakichi Toyoda

Occam’s Razor

Occam’s Razor is the idea that, if all else is equal, the theory with the least assumptions should be preferred. It’s also known as the parsimony principal, and it is a fundamental idea in all of science. It suggests that the best explanation for the data should be the simplest. Ceteris paribus means, in terms of tree building, that the best hypothesis will be the one that involves the least amount of evolutionary change.

Primary Source: William of Ockham

Hanlon’s Razor

It’s a method of eliminating unreliable explanations for human behaviour. Robert J. Hanlon once said: “Never attribute to malice what can be explained adequately by stupidity.”

Primary Source: Robert J. Hanlon

Maslow’s Hammer

When you only have a hammer at your disposal, everything appears to be a nail. Also called the law of instrument. It is a law, because an instrument has a limited number of uses to achieve its original purpose.

Primary source Abraham Maslow

Divergent and Convergent Thinking

Divergent thinking is a way of thinking that involves exploring different solutions to come up with creative ideas. Convergent Thinking is the process to find a solution for any problem. It is important to find a balance.

Primary Source: Joy Paul Guilford

Chronological Snobbery

Argument or thought that older stuff is inferior than the current stuff, due to social progress.

Lewis says: “The assumption that whatever has gone out of date is discredited on this account.” Lewis says: “The assumption that something has become outdated is discredited on this account.” It is important to find out why something has become outdated. It was it ever refuted? (If so, by whom, when, and with what degree of certainty) Or did it simply die out as fashions do. This does not tell us anything about the truth or falsity of its claims. This leads to the conclusion that our age is also “a period” and has its own illusions, just like every other period.

Lewis said that it was a good rule to read as many older books as you do newer ones.

Primary source C. S. Lewis and Owen Barfield

Weasel words

When someone makes it appear as if they have answered a question clearly or made a statement that is clear, but in reality they are saying something vague or inconclusive. The words “better”, ‘improved’, and ‘gains’do not indicate the extent of an argument.

Knightian Uncertainty

Frank Knight, an economist, argued that the term risk is used when we do not know what will happen in a given situation but are able to measure its probability. Uncertainty, on the other hand applies when we don’t have all the necessary information to calculate accurate probabilities.

Frank Knight, primary source

Map-Territory Relations

A map and the territory that it represents are two examples of abstract relationships between objects. If a person has only heard and read descriptions of an apple but never tried it, they will have no idea how it tastes.

Primary source: Alfred Korzybski

All Models Are Wrong

It’s a common aphorism used in statistics that states: “All models are wrong but some are helpful.” The thinking, attributed to George Box, is applicable to all models in science.

Primary Source: George Box

Middle Ground Fallacy

It is a fallacy to compromise two opposing viewpoints just because the middle ground exists. If, for example, one person claims that all elephants are able to fly and another states that none of them can, then it is a fallacy that you agree that some elephants may be able to fly.

Eisenhower Matrix

Dwight Eisenhower was the 34th president of the United States and he had to constantly make difficult decisions about what tasks he would focus on every day. He created the Eisenhower Matrix to prioritize and decide which tasks were urgent and important. This helped him sort out tasks that were less urgent or important, and those he could delegate. He said that what is important is rarely urgent and what is important is rarely urgent.

Primary source for Dwight Eisenhower


Study of systems and their functioning, as well as how they relate to larger systems. Also, the study includes how systems break down, or become bottlenecks. This is a methodical approach to examining problems in greater detail.

Mario Bunge, primary source

Lateral Thinking

Edward de Bono first coined the term in 1967. It’s a way of thinking that crosses otherwise irreconcilable disciplines to arrive at solutions which cannot be reached by deductive or logical methods. This is what we might call “thinking out of the box”.

Imagine this: A bartender asks a man for a drink of water when he walks in. The barman points a gun at the man. The man thanks the barman and leaves. Why?

The man was hiccuping.

Primary Source: Edward de Bono

Historical Wisdom

It is important to study the past in depth because it makes up the majority of history. Niall Ferguson, a Scottish historian, said that the dead outnumber those alive 14 to 1. We ignore the experience of such an enormous majority of humanity at our peril if we do not study the past.

Paradigm Shift

When a major change replaces the way you normally do or think about something.

Primary source: Thomas Kuhn


The researcher will move between theory and empirical evidence to allow for understanding to slowly emerge.

Primary source: Thomas Kuhn

Chauffeur Knowledge

Charlie Munger tells the story of Max Planck’s chauffeur in his book: “I often tell the apocryphal tale about Max Planck who, after winning the Nobel Prize, traveled around Germany, giving the same standard lectures on the new quantum physics.”

After a while, the chauffeur had memorized his lecture. He asked, “Would it be okay, Professor Planck? It’s boring to keep up with our routine.” Planck asked, “What if I did the lecture in Munich while you sat at the front wearing the chauffeur’s hat?” Planck replied, “Why not?” The chauffeur then stood up and delivered a long lecture about quantum mechanics. A physics professor then stood up and asked an absolutely horrifying question. The speaker replied, “I’m surprised to hear such a simple question in a city as advanced as Munich. My chauffeur will answer.

Planck knowledge is a product of hard work and aptitude. Chauffeur Knowledge has just started to talk the talk.

Charlie Munger, primary source

Pascal’s Wager

Blaise Pascal’s famous argument in favor of believing in God. Pascal said that believing in God was always a safer “bet”, because the value of what you can expect to gain by doing so is greater than if you don’t believe.

A third option (tertium ne datur) is not allowed on the question of God’s existence. There are two choices:

God Exists

God does not Exist

One will have to choose between the two options.

If you bet that God exists and are right, then you will win all your money.

You can win nothing if you bet that God does not exist. But, you can also lose everything if you bet on this.

Blaise Pascal as the primary source

Alder’s Law

It is not worth debating if something cannot be resolved by experiment.

Mental Models of Systems


As an organization or system performs the same work more often, it tends to become more efficient, but can also develop inefficiencies, such as bureaucracy. Positive feedback loops are the reason why scale can be an advantage.

While it is safe to say that scale advantages create economic moats that are extremely durable, it’s important to note that economies of size don’t always create moats. Ford’s scale edge disappeared as other automakers caught up to Ford’s productivity.

Pareto Principle

The Pareto Principle, also known as the 80/20 Rule and a power law, states that in many situations, 80% of a situation’s results come from only 20% of its causes. VilfredoPareto developed the principle after he showed that 20% of Italians owned 80% of Italy’s land.

This principle can be used in many different areas, including manufacturing, management and human resources. It is also applicable to personal time management. Despite its broad application, the principle does not work in every situation. Take care.

Primary Source: Vilfredo Pareto

Law of Diminishing Reward

Ceterus paribus at some point, in all production processes, adding more one factor will result, ceterus pareibus, in a lower incremental return per unit. There are always limitations in the world. The broth is spoiled by too many cooks.


An algorithm is a way to solve a particular problem. A set of rules that are used to accomplish a task in a sequence of steps is an algorithm. A recipe is an obvious example.

Primary source: Muhammad ibn Musa al-Khwarizmi

Margin of safety

Warren Buffett said that you need to know enough to be able to make an educated guess about the business value. You do not want to cut it too close. Ben Graham was referring to a safety margin when he said it. You wouldn’t buy a business worth $83,000,000 for only $80,000,000. You are leaving yourself a huge margin. You build a bridge and insist that it can support 30,000 pounds but only drive trucks up to 10,000 pounds across it. The same principle applies to investing.

The margin of safety, while useful for investing, is also a useful methodological concept that can be applied to nearly any endeavour in life.

Primary source: Benjamin Graham

Network Effects

A social network that only has one participant will not have any value. The value of a network is determined by the number users joining the network. This can sometimes lead to a “winner-takes-all” scenario.

Primary Source: Theodore Vail

Tipping Point

Malcolm Gladwell popularized the term tipping point, which is the moment when a product or a trend becomes viral or epidemic. Gladwell introduces the three variables that lead to the tipping moment: the law for the few, the sticky factor, and context. This mental model is a powerful tool for understanding how ideas gain traction within society.

Malcolm Gladwell as the primary source


The number of possible arrangements that atoms can take in a given system. It’s also a measure for randomness or uncertainty. Entropy is evident due to probability, since there are a finite number of ordered states and an infinite number of chaotic ones.

Rudolf Clausius

The Second Law of Thermodynamics

The second law of thermodynamics is directly related to the entropy. It states that over time, the total entropy will increase in an isolated system.

Imagine a group of balls in a box bouncing in an initial pattern. Over time, balls will bounce more chaotically. The entropy in the system increases.

Rudolf Clausius

Principle of Minimum Energy

The principle of minimum energy, which is a restatement the second law thermodynamics, states that the total energy of a closed system, with entropy fixed, will be the lowest at equilibrium.

Feedback Loops

The outcome of a particular system can either reinforce or amplify the system in a positive or negative way. The output becomes an input in the next step. It is a great way to visualize cause-and-effect relations by connecting them into loops.

It is largely related with systems thinking. It’s largely related to systems thinking.


George Soros is the primary proponent of reflexivity, a theory which states that feedback loops that occur between economic fundamentals and expectations can lead to price movements that are substantially and persistently different from equilibrium prices. Soros’s reflexivity theory runs against the idea of economic equilibrium, rational expectation, and efficient market hypothesis.

Primary Source: George Soros

Complex Adaptive Systems

A very important mental model where a complete understanding of a system’s parts does not necessarily translate into a full understanding of its behavior. Cities, large corporations and markets are examples of complex adaptive systems.

Michael Mauboussin says: When you look at the colony as a whole, and not the individual ants that make it up, the colony appears to be an organism. It’s robust. It’s adaptive. It has a cycle. The individual ant, however, is only concerned with the local environment and interactions. It is not aware of the global system. You can’t grasp the whole system from the behavior of ants. This is the essence of an adaptive complex system, and what makes it so difficult to understand. Cause and effect are hidden by the emergent state. We don’t know what is going on.

Pari-Mutuel Systems

Betting systems where all bets placed are pooled together and the odds of winning are calculated after the house takes. Horse race betting is a common example.

Charlie Munger said that the model he likes to simplify the idea of what happens in a stock market is the pari-mutuel at the racetrack. When you think about it, the pari-mutuel market is what a parimutuel system represents. Everyone goes to the pari-mutuel system and makes bets. The odds are affected by what is bet. This is what happens on the stock exchange.

Butterfly Effect

A small change to an initial condition may have a large impact on a subsequent condition. The term is derived from the analogy of a butterfly flapping its wings in Chicago, and a tornado in Tokyo.

In today’s connected world, the social impact of butterfly effect theory cannot be denied. Social systems are made unpredictable by butterfly effects.

Preferential Attachment

The popularity of something or the perception that it is better is a powerful force. Preferential attachment feeds network effects.


If the sum cannot be calculated by adding its parts, for example. When the sum of something is greater than its parts, e.g.

It is not reducible

A system or object cannot be further reduced, decreased, or simplified.

Tragedy of Commons

If a resource that is depletable is shared by users who act according to their self-interests, then it tends to be depleted.

If fishing is a source of income, and there are no regulations in place to control the fishing ponds, each fisher will act according to his own interests and catch as many as they can even if the other fishermen do the same.

Primary Source: William Forster Lloyd

Gresham’s Law

The system is named after Sir Thomas Gresham, a financier. “Bad money drives out the good”. The original law was based on the fact that minted coins tend to have less precious metals in them.

Imagine two coins of the same face value. Consider two coins, one made of copper and the other from silver. Gresham’s Law states that people will keep the silver coins but only use the copper ones as payment.

The law does not apply only to currencies. Avoid systems where bad behavior can win.

Primary Source: Sir Thomas Gresham


Nassim Taleb said this about antifragility. Some things thrive when they are exposed to randomness, disorder and stressors. They also love adventure, risk and uncertainty. There is no exact word to describe the opposite of fragile, despite the fact that the phenomenon is so common. We can call it antifragile. Antifragility goes beyond robustness or resilience. Antifragility is the opposite of resilience. The resilient can withstand shocks but remains the same, while the antifragile improves.

Primary source Nassim Taleb


The concept of backup system in engineering. Duplication of key components or functions in a system is done to increase its robustness or reliability. The numerous cables of a suspension bridge are an example of redundancy.

Via Negativa

A system can be improved by removing certain elements. Paradox of choice: More options can result in poorer decisions. Via negativea is the answer.

Warren Buffett’s 5/25 Rule is a via negativa. List 25 goals that you would like to achieve within the next 10 years. Choose the top five goals and ignore the other 20.

Lindy Effect

It is the idea that objects, ideas or technologies, which are not perishable, should live as long as their age. It is reasonable to expect that something which has survived for X-years will continue to survive for another X-years. As each additional period of life implies a longer remaining lifespan, the expected mortality decreases over time.

Primary Source: Albert Goldman

Bullwhip effect

Chain reaction: A reaction that starts out as a reaction to a certain outcome, but then escalates due to incomplete information.

Jay Forrester, primary source

Parkinson’s Law

The work expands in order to fit the time available. Cyril Northcote Parkinson first used the term in a funny essay in 1955 for The Economist.

Primary Source: Cyril Northcote Parkinson

The Symmetry of Ignorance

When solving a problem seems so impossible or difficult that everyone involved is essentially shooting in the darkness.

Horst Rittel wrote in 1972: Expertise and ignorance are distributed among all participants of a wicked problem. The participants in a wicked problem are equally ignorant because no one knows more than the other. Experts find it frustrating that there are no experts. If experts exist, they only have expertise in the way to deal with a problem.

Base Rates

Probability of a future event, for example. The success rate of all those who have done the activity you are about to do.

System Justification Theory

People will tolerate inefficient and unjust systems as long as their personal incentives align with defending or maintaining them. John T. Jost, Mahzarin Banaji and others first proposed the theory in 1994.

Primary source: John T. Jost; Mahzarin R. Banaji

Sturgeon’s law

A popular saying is that 90% of everything is garbage. Theodore Sturgeon quoted this saying to show that the vast majority (90%) of work produced in any field is low-quality.

Theodore Sturgeon, primary source

Ringelmann Effect

The productivity of individuals tends to decrease as a group grows. The French agricultural engineer Maximilien Ringelmann was the inspiration for its name.

Imagine a tug-of-war. The average performance of the participants tends to drop as more people get involved, because they feel that their effort is not important.

Maximilien Ringelmann as the primary source

Planck’s Principle

Max Planck once said: “A new scientific truth doesn’t triumph because it convinces its opponents or makes them see the light. It wins because they die, and a whole new generation is brought up with this new scientific truth.”

Max Planck

Group Attribution Error

Assuming falsely that the views or decisions of a group collectively reflect those of all members.

Primary Source: Scott T. Allison and David M. Messick

90-9-1 Rule

Only 1 percent of social media users actively create content. Another 9 percent participate by rating, commenting or sharing content. The remaining 90 percent watch, read and look without responding.

Braess’s Paradox

Dietrich Braess, a German mathematician, observed that adding a road would worsen traffic because of the increase in shortcuts and congestion.

Primary Source: Dietrich Braess

Perfect Solution Fallacy

It’s also known as the Nirvana Fallacy. This false dichotomy suggests that there is a perfect solution to a particular problem, and that certain actions should be avoided if only a small portion of the problem persists.

Primary Source: Voltaire

Peter Principle

Employees are promoted in an organization until they reach a level of incompetence. Laurence J. Peter developed this principle.

Primary Source: Laurence J. Peter

Foundational Species

Species which play a key role in the support of an ecosystem or a community. Many other species would not be able to survive in an ecosystem without these foundational species. The Federal Reserve and coral are both foundational species.

Primary Source: Paul K. Dayton

Google Scholar Effect

Google Sholar’s algorithm increases the preference for highly cited papers, since they appear at the top and receive more citations. New papers are rarely in the top positions, and receive less attention regardless of how important they may be to their respective fields.

Primary Source: Paul K. Dayton

Rebound Effect

If a 5% increase in fuel efficiency in a car results in a 2% decrease in fuel consumption, then there is a rebound effect of 60%. Driving faster or farther than usual could explain the 3% difference.

Murphy’s Law

All that is possible will occur.

Primary Source: Edward Murphy

Campbell’s Law

Donald Campbell is a social scientist. T. Campbell said that the more quantitative social indicators are used to make social decisions, the more they will be subject to corruption pressures.

It’s dangerous to quantitatively measure the wrong things and then set the wrong incentives by accident. This is because the situation is rarely noticed until the system fails. Take Enron’s accounting procedures. This is an example of cobra effect.

Donald T. Campbell, Primary source

Path Dependence

According to decision trees, the past is important in determining future options. In any situation, the choices that people have to make are limited by their past decisions. Path dependence can be a negative surprise, as explained by the tyranny small decisions.


Externalities occur when a third-party is forced to pay or receive a benefit over which it had no control. Negative externalities include pollution from industry, which can affect the health and safety of residents in close proximity. An example of a positive externality is if an individual maintains a beautiful house, which benefits their neighbors by increasing the market value of their property.

Primary Source: Henry Sidgwick

Open vs. closed platform

Open platforms or systems are those whose contents or functionality can be changed in ways other than what the creator intended. A closed platform, on the other hand is one that is “off-the-rack” – the creator retains control over its content.

Moore’s Law

It is interesting to note that the number transistors in a microchip roughly doubles every two years, while the price of computers has been halved. The experts agree that computers will reach the physical limit of Moore’s Law in the 2020s, because transistors are too hot to be made smaller.

Gordon E. Moore himself said about the limits of the law: “It can’t go on forever.” It’s the nature of exponential function. They hit a brick wall.

Gordon Moore

Metcalfe Law

The value of a communications system increases proportionally with the square of the total number of users (N2), or more precisely: N(N-1).

Metcalfe’s Law was first formulated by Robert Metcalfe in relation to Ethernet. However, it explains many network effects for technologies like the Internet, World Wide Web and Microsoft Windows.

Robert Metcalfe as the primary source

Theory of Constraints

A philosophy of governance that was introduced by Dr. Eliyahu Goldratt to help and leverage organizations in order to achieve their goals. The title is derived from the statement that any manageable systems is limited in achieving multiple goals by only a small number of constraints, and that there will always be at least one constraint.

Primary source Eliyahu M.Goldratt

Amara’s law

The short-term value of technology is underestimated, while the long-term value is greatly overestimated.

Roy Amara, Primary source

Mental Models of the Biological World


Encouragers who encourage humans and animals to perform certain actions. The idea is that people act in their best interests. It can be difficult to discourage an incentivized behavior, but it is equally hard to encourage one that’s not.


A complete natural environment, including all living and non-living organisms is called an ecosystem.

Ecological principles begin with the idea that all living organisms have a relationship that continues over time, both in terms of duration and permanence, to every element of their environment. It is important to consider all environmental conditions as part systems development.

Primary Source: Arthur Tansley


In ecosystems, an individual participant may flourish in a niche that is tailored to their needs. This is closely related to the circle competence.

Evolution through Natural Selection

Phenotype is the process of organisms changing over time due to changes in heritable traits. Charles Darwin developed the theory in 1859. It is supported by evidence from many scientific disciplines.

Darwin was relentless in his destruction of his ideas when he worked on the theory. He said that to kill an error was as good as and sometimes better than establishing a new fact or truth.

Primary source: Charles Darwin and Alfred Russel Wallace


When animals or organisms find that a common goal is more important than their own selfish interests, they are more likely to work together to achieve it.

Prisoner’s Dilemma

Cooperation may be hindered by individual self-interest.

Prisoner’s Dilemma is a situation in which two people acting out of self-interest do not achieve an optimal result. The typical prisoner’s dilemma is set up so that both people choose to protect themselves, at the expense the other person.

Primary source: Merrill Flood and Melvin Dresher


Changes in structure, behavior, or function of organisms can increase their adaptability to the environment.

Red Queen Effect

The species must adapt and evolve continuously to pass genes on to the next generations as well as resist extinction as other opposing types of species are evolving. The Red Queen told Alice in the sequel of Alice’s Adventures in Wonderland: You’ll need to run as fast as you can to stay in the same spot.

Primary Source: Leigh Van Valen


The biochemical copying of DNA within a cell. This is a requirement for successful cell division, as each daughter cell requires a full set of DNA in order to function.

Hedonic Treadmill

People return to the same baseline level of happiness, despite major life events and changes. The feeling of satisfaction and expectations rises with the results.

Primary Source: Campbell Brickman


Self-preservation ensures the survival of living organisms. Sigmund freud suggested that the instinct for self-preservation is one of the two that motivate human behavior. The other instinct is the sexual instinct. Later, Freud combined both into eros.

It is interesting to note that self-preservation may not be in our hearts. A mother, for example, might give up her life to save her child.

The reward center of organisms, also known as the pleasure centre, is composed of a grouping of neural structures responsible for motivation salience (the desire to receive a reward), learning by association, and emotions like joy, ecstasy and euphoria. If we don’t exercise discipline, our reward system can be hijacked by unhealthy addictions.


Natural selection, or evolution, allows traits originally intended for a single purpose to be repurposed for another.

Exaptation was introduced by biologists Steven Jay Gould & Elisabeth Vrba. It makes the point, that a trait’s present use doesn’t necessarily explain its historic origin. Exaptation is one way that traits have evolved. Feathers, for example, are an example. They were originally used to keep warm or attract mates. Feathers became necessary for modern birds to fly.

Primary Source: Stephen Jay Gould, Elisabeth Vrba


A small dose of something may be beneficial to an individual but can be dangerous or fatal if used in excess – for example. Alcohol or excessive exercise. When less is more, it’s the best.

Hugo Schulz, primary source

Dunbar Number

Robin Dunbar, an anthropologist from the 1990s studied the relationship between the average size of social groups and the size of primate brains. He discovered that the neocortex is required to bond and socialize with animals and to remember previous interactions. Dunbar measured the neocortex of humans and estimated their ability to maintain relationships. He concluded that humans can maintain around 150 contacts.

Primary Source: Robin Dunbar

Epidemic models

The SIR model is the most common model used to study and forecast epidemics. In their most basic form, epidemic models assume a disease’s infection rate and removal rate. The two factors will always determine how the epidemic develops.

Although epidemic models are excellent at explaining the spread and evolution of diseases, they can also be used to explain how small changes in other domains can lead to herd behavior. For example, by using epidemic models to better understand the transmission and reception of attitudes, we can better understand the feedback mechanisms which support financial bubbles as well as religious/political propagandists.

Pollyanna Principle

It’s much easier to recall pleasant memories than unpleasant ones. The subconscious mind is more optimistic than the conscious.


According to the Pollyanna Principle, the belief that society will decline if it focuses more on its negative aspects. The past is remembered as being better than what it actually was, and the future is expected to be worse.

Primary source Edward Gibbon

Empathy Gap

When an individual’s current mental state is different, they may underestimate the influence of mental state on behavior. A person who is calm may find it hard to predict their behavior if they are angered by someone.

Primary Source: George Loewenstein

Meat Paradox

Socrates believed that no one deliberately does anything wrong. Individuals can adapt their attitudes to actions. People care less about the well-being of cows when they eat beef jerky.

Primary Source: George Loewenstein

Emotional Contagion

Empathy is the ability to transfer emotions from one person to another through observation. Happiness and sadness are best friends.

Punctuated Equilibrium

Once a species appears in the fossil record they become stable and show little evolution for most of their geological past.

Primary source: Niles Elldredge, Stephen Jay Gould

Luck Surface Area

As with emotional contagion excitement and passion draw others into your orbit. Jason Roberts coined the phrase: “The amount of serendipity in your life is directly proportional the extent to which you are passionate about something combined with the number of people who hear you effectively. This is a very simple idea, but it’s extremely powerful because it suggests that you have direct control over the amount of good fortune you receive. You can make your own fortune.

Jason Roberts, primary source


Tribal loyalty is a policy that emphasizes the division of a group into tribes or the support for one or more tribes. Tribalism can be referred to as a way of thinking and acting in conformity. It is characterized by a loyalty to one’s tribe over one’s friends, country or other social groups.

Mental models in military and war

Asymmetrical War

Two parties with different military capabilities and methods of warfare. In this case, it is important for the weaker party to take advantage of their special advantages and the weaknesses of the other side in order to be able to accomplish its goals.

Attrition Warfare

The end of a war in which the parties involved are so powerful that they can only reach an agreement by exhausting each other’s resources. The one with the most reserves wins.

Two Front War

Parties prefer to focus their efforts on a single front, as it is easier to do so.

When an ally enters the war, a new front is created. Both fronts are weaker because it’s harder to move troops from one front to the other than to move them along a single line.

Choke Point

A narrow or small area through which a large number of soldiers can’t pass. A less powerful opponent can easily defeat them as they are unable to attack.


Counterinsurgency is one of the most extensive areas in asymmetrical war. It describes different tactics and strategies to combat armed rebellion. Counterinsurgency is a blend of civilian and military efforts aimed at simultaneously containing insurgency while addressing its root causes.

Mutually Assured Destruction

Robert McNamara developed this doctrine in response to Cuba’s crisis in 1962. It is implied that both parties will be destroyed if either of the two sides in a conflict use their nuclear weapons. The doctrine is based on theories about terror balance that argue powerful weapons are necessary to prevent the enemy from using similar weapons. The doctrine forced the warring parties to aim their weapons at the big cities of the enemy.

Guerrilla Warfare

A guerrilla movement is an organized armed conflict that aims to influence or control a government. States will usually be interested in classifying these movements as guerrillas. It means that what is regarded on one side as resistance or freedom struggles are on the other regarded as armed revolt and guerrilla movements.

Fighting the Last War

The act of using strategies and tactics that have worked in the past but are no longer effective.

Empty Fort Strategy

It is a psychological tactic that involves convincing an opponent that a fortification full of empty walls contains hidden soldiers or traps. This in turn causes the enemy to retreat.

Potemkin Village

Construction (literal or metaphorical) designed to fool others into believing that something is better than it is. The name comes from the Russian prince Grigorij, who built theater decorations depicting prosperous villages along the route of Catherine II in 1787 to give the impression he had achieved rapid prosperity on the newly-conquered peninsula.

Trojan Horse

The strategy of luring a warring side into allowing the enemy to sneak behind their defenses. Odysseus originally conceived of the strategy.


A strategy designed to stop a conflict from becoming a total war by achieving a quick operational victory.

Primary Source: Heinz Guderian


Massive strategic attack against the military and political leadership of an opponent, with the aim of eliminating its counterattack capability or at least reducing it significantly.

Detail of Defeat

It is better to send a large part of your own force in small groups and attack them sequentially than to engage the entire enemy force at once.

Pincer Ambush

The strategy of enclosing the enemy by coordinating attacks on both sides. When the units that are executing the pincer ambush come into contact on the other side, they close in the enemy and prevent them from retreating. They must either strike outside or seek help.

Shock & Awe

The use of overwhelming force to achieve rapid dominance against the enemy.


Use of a decentralized force against an opponent in a manner that emphasizes mobility, communication, unit autonomy, and coordination/synchronization.

Turning Motion

The strategy of separating the defensive forces from their primary defensive positions to allow an attacker to reach the rear guard.

How to Win Without Fighting

Sun Tzu said that a brilliant leader is one who can win without killing anyone.

Defence In Depth

The defensive side positions its units in such a way that they slowly absorb the strength and power of the attacking enemy.


Semi-permanent, permanent or semi-permanent defensive structure providing physical protection for a military unit.

Fabian Strategy

The strategy of wearing down the enemy instead of engaging in field battles or frontal assaults. By disrupting logistics or by affecting the morale. When time is on the side of warring parties or there are no other options, they use this tactic.

Primary Source: George Washington

Scorched Earth

The tactic of destroying fields, buildings, factories and other structures during a retreat. It is done to keep them out of enemy hands and to stop them contributing to their resources.


Continued reinforcement of the front military force until it reaches its maximum strength, followed by an assault with the superior force.

Mental models in political failure

Chilling effect

Fear of legal sanctions can cause a person to be reluctant or unwilling to exercise their rights. Free speech is a common example.

Primary source: John Milton

Third Rail of Politics

The metaphor is used to describe any topic that is so controversial it’s “untouchable”, in that any politician who approaches the subject will suffer politically.

Primary Source: Kirk O’Donnell

Regulatory Capture

Form of political corruption in which a government agency, instead of acting for the good of the society, represents commercial or special interest of a certain interest group or lobby that dominates an industry or sector.

Primary Source: George Stigler

State Capture

Systematic political corruption where private interests have a significant influence on a state’s decisions to their advantage.

Shirky principle

The institutions will do everything they can to maintain the problem for which they are the solutions.

Clay Shirky as the primary source

Mental Models of Rule of Law

Burdens of Proof

Obligation of a party to provide evidence in support of a claim.

Common Law

The courts are a part of the legal system, and they can interpret the law as well as create it by setting precedents.


A court’s previous judgments, rulings or decisions are used to guide or rule in subsequent cases or in cases that have similar circumstances.

Due Process

The principle of procedural law that everyone has a right to certain minimum protections, in order to ensure a fair and equitable outcome.

Duty of Care

A legal obligation to exercise reasonable care and pay attention when performing acts that may cause harm.

Good Faith

It is also called bona fides. This refers to a party who has been excusably ignorant of a relationship. In this context, what matters is a person’s assessment of how a reasonable person would have acted in a similar situation.


If something happens because of carelessness in a specific situation.

Presumption Of Innocence

Basic principle of criminal procedure which gives a person suspected of committing a crime, the right to be treated as innocent until proven guilty. This principle is so important, many democracies explicitly state it in their constitutions or laws.

Reasonable Doubt

In most criminal prosecution systems, the standard for evidence is that it must be beyond reasonable doubt.


Mental models are cognitive frameworks or paradigms that individuals use to interpret, understand, and make sense of the world around them.

Mental models help us navigate complex situations, make decisions, and solve problems by providing structured ways of thinking and understanding.

Developing effective mental models requires curiosity, learning, and practice. Reading, critical thinking, and exposure to diverse ideas contribute to their development.

Yes, mental models are versatile and can be applied in diverse fields such as business, science, relationships, and personal development.