Anchoring effect
The tendency for the first salient number, frame, or option to pull later estimates toward itself even when it is arbitrary or weakly relevant.
EstimationBaselineForecasting & planningPersonal decisions
Learning Path
Decision Under Uncertainty
Biases that quietly bend choice, forecasting, escalation, and project planning when the future is still unresolved.
9 biases
Foundational
50 min
By the end of this path
- See how anchors, overconfidence, and inside-view planning bend forecasts before execution begins.
- Practice switching from the inside story to the outside view.
- Build better habits for ranges, reference classes, and stopping rules.
How to study it
Work the pages in order, then loop back and compare which distortions happened earliest, which ones protected the first impression, and which ones interfered with later learning.
Next:
Biases in this path
This is a deliberate sequence, not just a themed pile. Start at the top if the context is new to you.
Overconfidence effect
The tendency to be more certain about judgments, forecasts, or abilities than the evidence warrants.
Hypothesis AssessmentOutcomeForecasting & planningTeams & management
Gambler's fallacy
The tendency to think that future probabilities are altered by past events, when in reality they are unchanged. The fallacy arises from an erroneous conceptualization of the law of large numbers . For example, "I've flipped heads with this coin five times consecutively, so the chance of tails coming out on the sixth flip is much greater than heads."
EstimationBaseline
Clustering illusion
The tendency to overestimate the importance of small runs, streaks, or clusters in large samples of random data (that is, seeing phantom patterns)
Hypothesis AssessmentOutcome
Planning fallacy
The tendency for people to underestimate the time it will take them to complete a given task
EstimationOutcome
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
Outcome bias
The tendency to judge the quality of a decision mainly by how things turned out rather than by the quality of the reasoning under the uncertainty that existed at the time.
EstimationOutcomePostmortems & learningTeams & management
Hindsight bias
The tendency, after an outcome is known, to see it as having been more obvious or predictable than it actually was beforehand.
RecallOutcomePostmortems & learningForecasting & planning