Psychology Mental Models

Mental models drawn from cognitive science, behavioural economics, and social psychology. Understanding how the human mind actually works — its biases, heuristics, and predictable irrationalities.

Mental models drawn from cognitive science, behavioural economics, and social psychology. Understanding how the human mind actually works — its biases, heuristics, and predictable irrationalities.

Browse all mental models in this discipline below.

Circle of Competence

Know what you know, know what you don't know, and stay honest about the boundary.

Foundation General Thinking

Pre-Mortem

Before starting, imagine the project has already failed. Then figure out why.

Foundation General Thinking

Hanlon's Razor

Never attribute to malice that which can be adequately explained by ignorance, incompetence, or neglect.

Foundation Psychology

Bayesian Updating

Start with your best guess, then update it proportionally as new evidence arrives.

Intermediate Mathematics

Confirmation Bias

We instinctively seek out information that confirms what we already believe — and ignore what contradicts it.

Foundation Psychology

Dunning-Kruger Effect

People with low competence in a domain tend to overestimate their ability, while experts tend to underestimate theirs.

Foundation Psychology

Loss Aversion

Losses hurt roughly twice as much as equivalent gains feel good — and this asymmetry distorts nearly every decision you make.

Intermediate Psychology

Incentives

Never ask why someone is behaving a certain way until you understand what they're incentivised to do.

Foundation Economics

Reciprocity

People feel compelled to return favours, match concessions, and treat you the way you treat them.

Foundation Psychology

Survivorship Bias

We study the winners and forget the losers — which distorts our understanding of what actually causes success.

Foundation Psychology

Sunk Cost Fallacy

Money, time, or effort already spent should not influence future decisions — but it almost always does.

Foundation Economics

Thinking in Bets

Separate decision quality from outcome quality. A good decision can have a bad outcome, and vice versa.

Intermediate Psychology

Anchoring

The first piece of information you encounter disproportionately shapes all subsequent judgments.

Foundation Psychology

Availability Heuristic

We judge the likelihood of events by how easily examples come to mind — not by actual frequency.

Foundation Psychology

Framing Effect

The same information presented differently leads to different decisions — even when the underlying facts are identical.

Intermediate Psychology

Narrative Fallacy

Humans compulsively construct stories to explain random events, creating false causation and illusory patterns.

Intermediate Psychology

Affect Heuristic

We make judgments based on current emotions rather than objective analysis — if something feels scary, we overestimate its risk.

Intermediate Psychology

Anchoring and Adjustment

We start from an initial value (the anchor) and adjust insufficiently from it — our final estimate stays too close to the starting point.

Foundation Psychology
⟫⟫

Bandwagon Effect

The tendency to adopt beliefs and behaviours simply because many other people do.

Foundation Psychology

Base Rate Neglect

We ignore how common or rare something is in general, and focus too much on the specific case in front of us.

Intermediate Mathematics
◎◎

Circle of Influence

Focus energy on what you can control, not what you can't. Most worry is spent on the wrong circle.

Foundation Psychology

Clustering Illusion

We see patterns in random data — streaks, clusters, and trends that are actually just statistical noise.

Intermediate Psychology

Complexity Bias

We tend to prefer complex explanations and solutions over simple ones, even when the simple version works better.

Foundation Psychology

Curse of Knowledge

Once you know something, you can't imagine not knowing it — making it hard to explain to someone who doesn't know it yet.

Foundation Psychology
◈◈

Decoy Effect

Adding a clearly inferior option makes one of the other options look more attractive by comparison.

Intermediate Psychology
⊟⊟

Distinction Bias

When comparing options side by side, we notice differences that wouldn't matter in actual use. The comparison mode distorts our evaluation.

Intermediate Psychology
⊕⊕

Domain Dependence

People often fail to transfer knowledge from one domain to another, even when the underlying principle is identical.

Intermediate Psychology
⊞⊞⊞

Dunbar's Number

Humans can maintain meaningful relationships with roughly 150 people. Beyond that, social cohesion requires formal structures.

Intermediate Psychology
⊕⊕⊕⊕

Endowment Effect

We value things more once we own them — simply possessing something increases its perceived worth.

Foundation Psychology
⊘⊘⊘

Gambler's Fallacy

Believing that past random events affect the probability of future random events — that a coin 'is due' for heads after several tails.

Foundation Psychology

Halo Effect

A positive impression in one area creates a biased positive impression in unrelated areas.

Foundation Psychology

Hindsight Bias

After something happens, we convince ourselves we knew it all along — even when we didn't.

Foundation Psychology

Hyperbolic Discounting

We strongly prefer immediate rewards over future ones, even when waiting would give us much more. $100 today feels better than $120 next month.

Foundation Psychology
⊙⊙⊙

Identity-Protective Cognition

We evaluate evidence not by its quality but by whether it supports the identity of the group we belong to.

Advanced Psychology
⊞⊞⊞⊞⊞

IKEA Effect

We overvalue things we helped create, regardless of their objective quality.

Foundation Psychology

Incentive-Caused Bias

Never ask someone for their opinion on something when their income depends on giving you a particular answer.

Foundation Psychology

Mental Accounting

We treat money differently depending on where it came from or what we've labelled it, even though a dollar is a dollar.

Intermediate Economics
⟳⟳

Mere Exposure Effect

We prefer things simply because we've been exposed to them repeatedly — familiarity breeds liking, not contempt.

Foundation Psychology
⊙⊙

Mimetic Desire

We don't want things independently — we want things because other people want them. Desire is borrowed, not original.

Intermediate Psychology
◉◉

Naive Realism

The belief that you see the world objectively, and anyone who disagrees must be uninformed, irrational, or biased.

Intermediate Psychology

Negativity Bias

We give more weight to negative experiences, information, and emotions than to equally positive ones.

Foundation Psychology
⊞⊞⊞⊞

Paradox of Choice

More options don't always make us happier — beyond a threshold, additional choices increase anxiety, regret, and decision paralysis.

Foundation Psychology
⊿⊿

Peak-End Rule

We judge experiences primarily by their most intense moment and their ending — not by the average or total.

Intermediate Psychology

Planning Fallacy

We systematically underestimate how long tasks will take, even when we have direct experience of past overruns.

Foundation Psychology

Prisoner's Dilemma

When two parties would both benefit from cooperating but each has an individual incentive to defect, the result is often mutual loss.

Intermediate Economics
⊣⊣

Reactance

When people feel their freedom is threatened, they do the opposite of what's being asked — even if compliance would benefit them.

Intermediate Psychology

Regression to the Mean

Extreme performances tend to be followed by more average ones — not because of any causal force, but because extreme results are statistically unusual.

Intermediate Mathematics

Satisficing vs Maximising

Choose the first option that meets your criteria rather than exhaustively searching for the best possible option.

Foundation Psychology

Scope Insensitivity

We fail to scale our emotional response proportionally. Saving 200,000 birds doesn't feel 100x more important than saving 2,000.

Intermediate Psychology

Selection Bias

The sample you're looking at isn't random — it was filtered in ways you may not notice.

Intermediate Mathematics

Skin in the Game

People with something to lose make better decisions than those who are insulated from consequences.

Intermediate Economics

Spotlight Effect

We overestimate how much other people notice our appearance, behaviour, and mistakes.

Foundation Psychology

Status Quo Bias

We prefer the current state of affairs simply because it's familiar — even when alternatives are objectively better.

Foundation Psychology

Streetlight Effect

Searching for answers where it's easy to look, rather than where the answers actually are.

Foundation Psychology

The Peter Principle

People are promoted based on their current performance until they reach a role they're incompetent at — where they remain.

Foundation Psychology

Winner's Curse

In competitive bidding, the winner often overpays because winning means you valued the item more than everyone else — likely too much.

Intermediate Economics