Charlie Munger’s 25 Cognitive Biases, Explained With Examples

Quick Answer: What are cognitive biases in investing?

Cognitive biases are patterns of thought or behavior that can distort how investors weigh evidence. Charlie Munger discussed roughly 25 tendencies, while the SEC has described investor behaviors such as familiarity bias and the disposition effect. A checklist cannot prevent mistakes, but it can prompt a search for missing evidence.

Why This Matters

Encourages Lifelong Learning. Recognizing that biases exist can prompt further research.

Improves Decision-Making. Recognizing a possible pitfall can prompt a check of the data and assumptions.

Enhances Critical Thinking. A written opposing case can help test an assumption.

Avoids Investment Surprises. Spotting fear of missing out or attachment to a losing position can prompt a pause and a review of the original rationale.

Promotes Self-Awareness. Learning the patterns can help you notice when emotion may influence a decision.

Bias 1: Reward and Punishment Superresponse Tendency

What it is. We respond strongly to incentives (rewards) and punishments, sometimes focusing on short-term gains or avoiding penalties instead of long-term value.

Dated case — September 8, 2016. The CFPB reported that sales targets and compensation incentives helped drive employees to open unauthorized customer accounts. This enforcement case shows why an analyst should examine what employees are rewarded for, alongside reported growth. It does not establish that incentives explain every decision at the bank. Wells Fargo enforcement: source.

Tip to Manage. Check if an incentive is driving your decision. Ask, “Am I chasing a bigger reward, or am I doing solid research?”

Bias 2: Liking/Loving Tendency

What it is. We overlook flaws in people or things we admire. Emotional attachment can cloud our judgment.

Dated case — 1972. Participants gave more favorable personality evaluations to physically attractive people. Dion’s 1990 first-person retrospective describes the 1972 finding. This is a related example of positive impressions spreading to other judgments; it did not test stock selection or establish that appearance predicts character. Dion, Berscheid and Walster: source.

Tip to Manage. Seek a second opinion or data that challenges your positive feelings. If facts contradict your “love” for a stock, pay closer attention.

Bias 3: Disliking/Hating Tendency

What it is. We focus on negatives when we dislike something, dismissing potential positives.

Dated case — 1979. People with opposing views on capital punishment assessed two purported studies. Each side favored the evidence supporting its existing position, and opinions became more polarized. This illustrates attitude-based discounting, a related mechanism rather than a direct test of hatred. In investing, evaluate the evidence separately from feelings about the business. Lord, Ross and Lepper: source.

Tip to Manage. Separate personal feelings from factual performance. Ask yourself, “If I didn’t dislike this sector, would it look like a decent investment?”

Bias 4: Doubt-Avoidance Tendency

What it is. We resolve doubt by making hasty decisions under uncertainty.

Dated case — 1983. Time pressure increased reliance on early information in impression judgments and on anchors in a numerical task. Kruglanski and Webster’s 1996 review describes these 1983 experiments. They illustrate premature closure under pressure, not a finding that every quick decision is wrong. Before acting, identify which missing facts could change the conclusion. Kruglanski and Freund: source.

Tip to Manage. When you feel rushed, pause. Try to gather basic facts and weigh alternatives, instead of doing an “all-or-nothing” move.

Bias 5: Inconsistency Avoidance Tendency

What it is. We resist change and stick to old habits, even when evidence suggests it’s time to adapt.

Dated case — 1959. After repetitive tasks, participants were paid $1 or $20 to tell another person the work was enjoyable. The $1 group later rated the tasks more positively than the $20 group. This specific laboratory result illustrates changing an attitude to reconcile a prior action; it does not demonstrate that every investor rationalizes a purchase. Festinger and Carlsmith: source.

Tip to Manage. Periodically reassess your investing approach or portfolio. Ask, “What’s changed in the market or my goals? Do I need to adjust?”

Bias 6: Curiosity Tendency

What it is. Our natural desire to learn can drive us to seek new knowledge and better decisions.

Dated case — 2009. Participants rated their curiosity about trivia questions, then saw the answers. Greater initial curiosity was associated with better recall of surprising answers one to two weeks later. This is evidence about learning in that task, not proof that curiosity creates investment profits. Use interest to generate questions, then verify the answers. Kang and colleagues: source.

Tip to Manage. Encourage your curiosity but combine it with due diligence. Don’t just learn new things; check their real-world relevance.

Bias 7: Kantian Fairness Tendency

What it is. We want the world to be perfectly fair and get upset when it’s not.

Dated case — 2003. In an Ultimatum Game, participants could accept a proposed money split or reject it so both players received nothing. Some rejected unfair offers; the researchers also measured brain activity. Fairness can be a legitimate preference, not simply an error. The case shows why financial choices may reflect more than the immediate cash amount. Sanfey and colleagues: source.

Tip to Manage. Recognize reality may not match ideal fairness. If you value ethical investing, incorporate it in a balanced way, not also frantic.

Bias 8: Envy/Jealousy Tendency

What it is. Seeing others get results can trigger envy or jealousy, prompting rash moves.

Dated case — 2009. Participants read about other people’s circumstances. Superior outcomes in areas relevant to the participant were associated with stronger reported envy. This was a social-comparison experiment, not a trading study. When someone else reports a gain, separate the feeling of comparison from evidence about the investment’s price, risk and suitability. Takahashi and colleagues: source.

Tip to Manage. Focus on your research and goals. Past gains from others don’t guarantee future returns for you.

Bias 9: Reciprocation Tendency

What it is. We feel obligated to return favors, sometimes ignoring whether it’s in our best interest.

Dated case — 1971. In a laboratory study, a confederate either gave the participant an unsolicited soft drink or did not, then asked the participant to buy raffle tickets. The favor increased compliance. A received favor can influence a later request; it does not make the request financially sound. Judge a recommendation independently of gifts or helpfulness. Regan: source.

Tip to Manage. Appreciate the favor but do your own research. Reciprocate politely without compromising your strategy.

Bias 10: Influence From Mere Association Tendency

What it is. We get influenced solely because a company is associated with something or someone we like.

Dated case — 1920. The researchers paired a white rat with a loud noise in a single infant case and reported a subsequent fear response to the rat. This ethically troubling, limited case illustrates learned association. It does not establish a lifelong outcome or a universal rule. An investment’s association with a familiar image supplies no evidence about its value. Watson and Rayner: source.

Tip to Manage. Ask, “What actual data supports this investment?” Strip away star power or hype and evaluate the real numbers.

Bias 11: Simple, Pain Avoiding Psychological Denial

What it is. We deny or ignore painful facts to avoid mental discomfort.

Dated case — 2011. Participants estimated their chances of adverse future events, received statistical information, and revised their estimates. Updating was stronger for desirable than undesirable information. This related belief-updating result is not a clinical diagnosis of denial and did not test realized stock losses. Write down how both favorable and unfavorable evidence should change an investment view. Sharot, Korn and Dolan: source.

Tip to Manage. Face facts head-on. Periodically review holdings to identify any denial. If the fundamentals are poor, it might be time to exit.

Bias 12: Excessive Self-Regard Tendency

What it is. Overconfidence, where we think our abilities or knowledge are above average.

Dated case — 1981. In US and Swedish samples, a majority rated their driving skill above that of their comparison group. These self-ratings illustrate an above-average effect in a particular domain; they did not measure investing skill. Compare a claimed investing advantage with an appropriate benchmark and recorded results instead of relying on confidence alone. Svenson: source.

Tip to Manage. Seek feedback or track your results vs. a benchmark. Let data check your self-assessment.

Bias 13: Over-Optimism Tendency

What it is. We expect everything will go right, underestimating potential problems.

Dated case — 1980. College students compared their chances of future life events with classmates’ chances. On average, they rated positive events as more likely for themselves and negative events as less likely. This is comparative optimism in the studied sample, not a forecast of anyone’s future. Include adverse outcomes when evaluating an investment plan. Weinstein: source.

Tip to Manage. Balance hope with reality. Look for objective signals (like revenue trends or industry outlook) before doubling down.

Bias 14: Deprival Superreaction Tendency

What it is. We strongly prefer avoiding losses over acquiring gains, sometimes causing irrational holding of losing positions.

Dated case — 1990. Participants endowed with mugs generally required more money to sell than buyers were willing to pay. This endowment-effect experiment is related to reluctance to give up an owned item; it does not demonstrate every kind of loss reaction. Reassess an existing holding using current evidence rather than treating ownership as an extra source of value. Kahneman, Knetsch and Thaler: source.

Tip to Manage. Calculate opportunity cost. Ask, “Would I buy this stock today at its current price?” If not, consider selling.

Bias 15: Social Proof Tendency

What it is. We copy others’ actions, assuming the crowd must be right.

Dated case — 1955. In line-length judgments, an otherwise unanimous group deliberately gave wrong answers. Some participants conformed despite the visible comparison. Others resisted, so conformity was not universal. The published account illustrates social pressure in that setting. For an investment, count independent evidence rather than assuming a large crowd has checked the same facts. Asch’s published account: source.

Tip to Manage. Cross-check hype with fundamentals. Just because “everyone else” is buying doesn’t guarantee it’s wise.

Bias 16: Contrast Misreaction Tendency

What it is. Judging something as a bargain or “better” simply because it’s compared to something worse.

Dated case — 1981. Respondents considered a hypothetical shopping choice in an actual experiment: drive 20 minutes to save $5 on a calculator priced at $15 or $125. Willingness to travel was 68% versus 29%, although the saving was identical. These are reported experimental responses, not completed purchases. Compare an investment’s absolute economics as well as its relative appearance. Tversky and Kahneman: source.

Tip to Manage. Compare a stock’s metrics to objective benchmarks (like industry averages), not just the first or easiest point of comparison.

Bias 17: Stress Influence Tendency

What it is. Under stress, we often resort to extreme, hasty decisions.

Dated case — 2009. An acute-stress experiment compared financial choices involving gains and losses. Stress strengthened the difference between risk preferences in the two domains. It did not simply make everyone take more risk. The result supports pausing to examine how a pressured setting may affect a decision, while recognizing that laboratory choices differ from an investment account. Porcelli and Delgado: source.

Tip to Manage. Step away briefly if you feel stress rising. Reassess when calm; consider an emergency plan for market downturns so you don’t act impulsively.

Bias 18: Availability Misweighing Tendency

What it is. We rely too heavily on information that’s easy to recall (e.g., recent news headlines).

Dated case — 1973. Participants heard lists containing 19 famous names of one sex and 20 less-famous names of the other. Of 99 people asked which category was more frequent, 80 selected the famous-name category incorrectly. The memorable examples outweighed the count. When assessing investment risk, check frequencies and the full record rather than relying on the easiest headline to recall. Tversky and Kahneman: source.

Tip to Manage. Gather additional sources. Look at historical performance, not just the latest dramatic headline.

Bias 19: Use It Or Lose It Tendency

What it is. Skills fade if not regularly practiced or updated.

Dated case — 2006. Students who practiced recalling prose material retained more on a test one week later than students who repeatedly reread it. Roediger’s own research account describes this experiment. It concerns retrieval practice, not every skill or a guarantee against forgetting. Practice explaining a financial concept from memory, then correct gaps against the source. Roediger and Karpicke: source.

Tip to Manage. Keep learning. Periodically refresh key investing concepts or your analytical approach.

Bias 20: Drug Misinfluence Tendency

What it is. Alcohol or substance use impairs judgment and leads to impulsive decisions.

Dated case — 2004. Adults received alcohol or a control condition and completed a cued response-inhibition task. Alcohol increased the dependence of inhibitory control on environmental cues. This was a controlled task, not an observation of stock trades or guidance about a safe dose. Avoid treating a momentary feeling of confidence as evidence of unimpaired financial judgment. Fillmore: source.

Tip to Manage. Make key investment decisions sober and alert, with a clear mind.

Bias 21: Senescence Misinfluence Tendency

What it is. As we age (or when skills go unused), we lose sharpness, missing new market realities.

Dated case — 2009. The study compared cognitive measures across adults and examined repeated testing. Several measures showed negative age associations, while accumulated knowledge, including vocabulary, followed a different pattern. Cross-sectional differences are not an individual diagnosis or a complete causal account of aging. Age alone does not establish whether someone can evaluate a particular investment. Salthouse: source.

Tip to Manage. Stay mentally active and flexible. Seek fresh info about trends or get input from trusted younger colleagues or research channels.

Bias 22: Authority Misinfluence Tendency

What it is. We tend to follow authority figures blindly, even when they’re wrong or outside their expertise.

Dated case — 1963. Participants were instructed by an experimenter to administer apparently increasing electric shocks. Many continued despite signs of distress; the learner was a confederate and did not receive those shocks. The ethically controversial experiment illustrates obedience in that setting. An authoritative title or confident recommendation still needs supporting investment evidence. Milgram’s published experiment: source.

Tip to Manage. Verify the authority’s track record and underlying logic. Authority is a starting point, not the final answer.

Bias 23: Twaddle Tendency

What it is. We fill silence with meaningless chatter and treat that chatter as if it carried real information.

Dated case — 2015. Researchers presented syntactically structured statements made from randomly arranged buzzwords. Some participants rated them as profound despite their lack of clear meaning. Responses varied; the study does not label every abstract statement meaningless. For an investment claim, ask what measurable proposition is being made and what evidence would show it to be wrong. Pennycook and colleagues: source.

Tip to Manage. Filter ruthlessly. If a source isn’t backed by data or doesn’t change your decision, ignore it. Read fewer, better things.

Bias 24: Reason Respecting Tendency

What it is. An explanation can increase persuasion even when it is weak or irrelevant. Ask whether the reason actually supports the claim.

Dated case — 1978. In a photocopier-queue experiment, a small request accompanied by a reason that added no useful information gained more compliance than a request without a reason. The pattern changed for a larger request. This limited result does not mean any reason always persuades. Evaluate whether an investment explanation adds relevant evidence, rather than merely sounding explanatory. Langer, Blank and Chanowitz: source.

Tip to Manage. Test the quality of the reasoning, not just the presence of it. “Because” is not the same as “true.”

Bias 25: What is the Lollapalooza tendency?

Munger used this label when several psychological tendencies act together and reinforce one another. Dated case — January 28, 1986. The Rogers Commission documented communication failures, incomplete information and conflicts between engineering evidence and management judgments before Challenger’s launch. Our teaching interpretation is that several influences can reinforce one decision. The Commission did not diagnose Munger’s tendencies. This is an organizational decision case, not a claim that any one bias caused the accident. Rogers Commission, Chapter V. Inspect each influence and the underlying facts; popularity alone does not establish that an investment is wrong.

Check your understanding

1. Which behavior illustrates familiarity bias?
A. Favoring only familiar companies without checking concentration. B. Reading a filing. C. Comparing fees.

2. What is the disposition effect?
A. Buying every popular stock. B. A tendency to keep losing holdings too long and sell winners too soon. C. A guaranteed market pattern.

3. Does recognizing a bias guarantee an unbiased decision?
A. Yes. B. Only for experienced investors. C. No; evidence and a decision process still matter.

Why question: Why should a reader write down a reason that challenges a favorite investment idea?

Try it: challenge a familiar company idea

Open the SEC EDGAR search prefilled for Apple. Imagine you like the company because its products are familiar. In the latest 10-K, find one risk factor and one piece of evidence about its business. Write a reason to be interested and a reason to be cautious. This is a research exercise, not a recommendation.