Stupid.si
Why smart people do dumb things - the science of thinking errors
Intelligence does not protect you from bad decisions. Confirmation bias, overconfidence, sunk cost - these thinking traps catch experts as often as anyone else. Learn the cognitive science of how good minds go wrong, and how to catch yourself before you do.
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What you get
Everything Stupid.si gives you
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Bias glossary
Confirmation bias, anchoring, and more - clearly explained.
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Real-world case studies
See these thinking traps play out in real decisions.
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Decision checklists
Practical tools to slow down before a bad call.
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Saved study threads
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Go deeper
The Science of Thinking Errors
Core concepts in cognitive bias and decision science.
Cognitive Biases
- Confirmation Bias — Favoring information that confirms what you already believe.
- Anchoring — Over-relying on the first piece of information offered.
- Availability Heuristic — Judging likelihood by how easily examples come to mind.
- Overconfidence Effect — Subjective confidence in judgments reliably exceeds objective accuracy.
Logical Fallacies
- Sunk Cost Fallacy — Continuing a course of action because of past investment, not future value.
- Slippery Slope — Assuming one step inevitably leads to an extreme outcome without evidence.
- False Dichotomy — Presenting only two options when more actually exist.
Decision Science Research
- Kahneman and Tversky — Pioneers of behavioral economics and prospect theory.
- System 1 and System 2 — Fast, intuitive thinking versus slow, deliberate reasoning.
Debiasing Techniques
- Premortems — Imagining a decision has already failed, then working backward to find why.
- Seeking Disconfirmation — Actively looking for evidence against your own view.
- Slowing Down — Adding deliberate delay to high-stakes decisions to engage System 2 thinking.
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