CogBias

Action bias

The tendency for someone to act when faced with a problem even when inaction would be more effective, or to act when no evident problem exists

DecisionBaseline

Additive bias

The tendency to solve problems through addition, even when subtraction is a better approach

DecisionBaseline

Ambiguity effect

The tendency to avoid options when their probabilities are unclear, even if the unclear option may not actually be worse than the familiar one.

DecisionAssociationForecasting & planningPersonal decisions

Authority bias

The tendency to give excess weight to the opinion of a high-status or authoritative source independent of whether the source has earned that weight on the specific issue.

DecisionAssociationTeams & managementMedia & politics

Automation bias

The tendency to depend excessively on automated systems which can lead to erroneous automated information overriding correct decisions

DecisionAssociation

Ballot order effect

Where candidates who are listed first often receive a small but statistically significant increase in votes compared to those listed in lower positions

DecisionBaseline

Cheerleader effect

The tendency for people to appear more attractive in a group than in isolation

DecisionBaseline

Compassion fade

The tendency to behave more compassionately towards a small number of identifiable victims than to a large number of anonymous ones

DecisionAssociation

Compromise effect, choices affected if presented as extreme or average

Choices affected if presented as extreme or average

DecisionBaseline

Decoy effect

Where preferences for either option A or B change in favor of option B when option C is presented, which is completely dominated by option B (inferior in all respects) and partially dominated by option A

DecisionBaseline

Default effect

The tendency to favor the preselected or default option simply because it is already positioned as the path of least resistance.

DecisionAssociationChoice architecturePersonal decisions

Denomination effect

The tendency to spend more money when it is denominated in small amounts (e.g., coins) rather than large amounts (e.g., bills)

DecisionBaseline

Disposition effect

The tendency to sell an asset that has accumulated in value and resist selling an asset that has declined in value

DecisionBaseline

Distinction bias

The tendency to view two options as more dissimilar when evaluating them simultaneously than when evaluating them separately

DecisionBaseline

Doubling-back aversion

The tendency for people to avoid retracing their steps or restarting a task, even when doing so would clearly save time or effort, because it feels like undoing past progress rather than making future gains

DecisionInertia

Dread aversion

Just as losses yield double the emotional impact of gains, dread yields double the emotional impact of savouring

DecisionAssociation

Effort justification

A person's tendency to attribute greater value to an outcome if they had to put effort into achieving it. This can result in more value being applied to an outcome than it actually has. An example of this is the IKEA effect, the tendency for people to place a disproportionately high value on objects that they partially assembled themselves, such as furniture from IKEA, regardless of the quality of the end product

DecisionSelf-Perspective

Endowment effect

The tendency to value something more highly once it is already owned, possessed, or treated as part of the current arrangement.

DecisionInertiaPersonal decisionsMarkets & valuation

Framing effect

The tendency for the same underlying information to produce different judgments depending on how the options or outcomes are described.

DecisionAssociationMedia & politicsPersonal decisions

Functional fixedness

A tendency limiting a person to using an object only in the way it is traditionally used

DecisionInertia

Hyperbolic discounting

Where discounting is the tendency for people to have a stronger preference for more immediate payoffs relative to later payoffs. Hyperbolic discounting leads to choices that are inconsistent over time—people make choices today that their future selves would prefer not to have made, despite using the same reasoning. Also known as current moment bias or present bias, and related to Dynamic inconsistency . A good example of this is a study showed that when making food choices for the coming week, 74% of participants chose fruit, whereas when the food choice was for the current day, 70% chose chocolate

DecisionAssociation

Law of the instrument

An over-reliance on a familiar tool or methods, ignoring or under-valuing alternative approaches. "If all you have is a hammer, everything looks like a nail."

DecisionSelf-Perspective

Less-is-better effect

The tendency to prefer a smaller set to a larger set judged separately, but not jointly

DecisionBaseline

Loss aversion

The tendency for potential losses to weigh more heavily than equivalent gains when choices are being evaluated.

DecisionAssociationPersonal decisionsForecasting & planning

Mere exposure effect

The tendency to like, trust, or feel more comfortable with something simply because it has become familiar.

DecisionInertiaMedia & politicsPersonal decisions

Money illusion

The tendency to concentrate on the nominal value (face value) of money rather than its value in terms of purchasing power

DecisionBaseline

Neglect of probability

The tendency to ignore or drastically underuse probability information when making decisions under uncertainty.

DecisionAssociationRisk judgmentPublic policy

Non-adaptive choice switching

After experiencing a bad outcome with a decision problem, the tendency to avoid the choice previously made when faced with the same decision problem again, even though the choice was optimal. Also known as "once bitten, twice shy" or "hot stove effect"

DecisionAssociation

Normalcy bias

The tendency to assume that things will keep functioning more or less normally, which leads people to underprepare for unprecedented or fast-moving disruption.

DecisionBaselineRisk judgmentPublic policy

Not invented here

An aversion to contact with or use of products, research, standards, or knowledge developed outside a group

DecisionSelf-Perspective

Phantom effect

Choices affected by dominant but unavailable options

DecisionBaseline

Plan continuation bias

Failure to recognize that the original plan of action is no longer appropriate for a changing situation or for a situation that is different from anticipated

DecisionInertia

Present bias

The tendency to give disproportionate weight to immediate costs and payoffs relative to later ones, even when the later consequences are larger.

DecisionOutcomePersonal decisionsForecasting & planning

Prevention bias

When investing money to protect against risks, decision makers perceive that a dollar spent on prevention buys more security than a dollar spent on timely detection and response, even when investing in either option is equally effective

DecisionAssociation

Projection bias

The tendency to overestimate how much your future preferences, values, and reactions will resemble whatever you feel strongly right now.

DecisionBaselinePersonal decisionsForecasting & planning

Pseudocertainty effect

The tendency to make risk-averse choices if the expected outcome is good but risk-seeking choices if it is bad

DecisionAssociation

Reactance

The tendency to push back against a perceived attempt to limit one's freedom of choice, sometimes by moving toward the very option one was being steered away from.

DecisionOutcomePersonal decisionsConflict & persuasion

Reactive devaluation

Devaluing proposals only because they purportedly originated with an adversary

DecisionSelf-Perspective

Risk compensation

The tendency to take greater risks when perceived safety increases

DecisionAssociation

Scope neglect

For example, being willing to pay as much to save 2,000 children or 20,000 children

DecisionBaseline

Semmelweis reflex

The tendency to reject new evidence that contradicts a paradigm

DecisionInertia

Shared information bias

The tendency for group members to spend more time and energy discussing information that all members are already familiar with (i.e., shared information), and less time and energy discussing information that only some members are aware of (i.e., unshared information)

DecisionInertia

Social comparison bias

The tendency, when making decisions, to favour potential candidates who do not compete with one's own particular strengths

DecisionSelf-Perspective

Status quo bias

The tendency to prefer the current option, default, or inherited arrangement simply because it is the current option, default, or inherited arrangement.

DecisionInertiaPersonal decisionsTeams & management

Sunk cost effect

The tendency to keep investing in a losing path because of what has already been spent, even when the forward-looking case has weakened.

DecisionInertiaPersonal decisionsTeams & management

Well travelled road effect

The tendency to underestimate the duration taken to traverse oft-travelled routes and overestimate the duration taken to traverse less familiar routes

DecisionInertia

Zero-risk bias

The preference for reducing a small risk to zero over a greater reduction in a larger risk

DecisionAssociation