Cognitive Biases

Common mental shortcuts and distortions that shape perception, judgment, and decision-making.

Attention & memory biases

• Availability heuristic — overestimating importance of easily recalled events
• Recency bias — favoring recent information over older information
• Peak–end rule — judging experiences by the most intense moment and the ending
• Negativity bias — paying more attention to negative events than positive ones
• Selective attention — noticing only what aligns with current focus
• False memory effect — recalling events differently from how they occurred

Belief & interpretation biases

• Confirmation bias — seeking information that supports existing beliefs
• Belief perseverance — holding beliefs even after evidence is disproven
• Anchoring — relying heavily on the first piece of information encountered
• Framing effect — decisions shifting when the same information is worded differently
• Halo effect — positive impressions coloring unrelated judgments
• Horn effect — negative impressions coloring unrelated judgments

Social & interpersonal biases

• Fundamental attribution error — attributing others’ actions to character, not context
• In-group bias — favoring people perceived as part of one's group
• Out-group homogeneity — assuming outsiders are all similar
• Projection bias — assuming others think or feel the same way
• Self-serving bias — attributing successes internally and failures externally
• False consensus effect — overestimating how widely others share one's opinions

Risk & decision-making biases

• Loss aversion — avoiding losses more strongly than seeking gains
• Sunk cost fallacy — continuing a failing course due to prior investment
• Optimism bias — underestimating risks and negative outcomes
• Pessimism bias — expecting negative outcomes more than warranted
• Overconfidence effect — overestimating accuracy of personal judgments
• Gambler’s fallacy — believing past events affect independent future outcomes

Reasoning & logic biases

• Motivated reasoning — processing information to reach desired conclusions
• Dunning–Kruger effect — low skill leading to inflated self-assessment
• Appeal to authority — overvaluing statements from high-status individuals
• Correlation vs. causation confusion — mistaking association for causality
• Simplification bias — preferring simple explanations even when insufficient
• Patternicity — perceiving patterns where none exist

Time & planning biases

• Planning fallacy — underestimating time or resources needed
• Present bias — prioritizing immediate rewards over long-term outcomes
• Hyperbolic discounting — rapidly devaluing future benefits
• Impact bias — overestimating duration of emotional reactions
• Procrastination through short-term mood repair
• Normalcy bias — assuming systems remain stable despite evidence of change

Short description

Mental shortcuts that simplify decisions but frequently distort judgment and perception.