September 8, 2026 · Yunus Emre Vurgun

Cognitive Biases: A Decision Checklist

psychology · decisions · reference · checklist

Seven biases distort most technical decisions: what gets built, what gets funded, and which incidents get blamed on people instead of systems. Run important calls past this checklist before committing.

The seven biases

BiasWhat it doesCounter-move
Confirmation BiasFavoring information that confirms existing beliefs.Assign someone to argue the opposite case.
AnchoringOver-relying on the first piece of information offered.Get independent estimates before sharing numbers.
Availability HeuristicJudging probability by how easily examples come to mind.Ask for base rates, not anecdotes.
Dunning-Kruger EffectUnskilled individuals overestimate their ability.Require a worked example, not a confidence claim.
Sunk Cost FallacyContinuing an endeavor because of previously invested resources.Ask: would we start this today, knowing what we know?
Hindsight BiasBelieving past events were more predictable than they were.Write predictions down before outcomes are known.
Bandwagon EffectAdopting beliefs or behaviors because others do.Ask what the dissenters know that you don't.

The one that kills projects

Sunk cost is the expensive one. Teams keep funding a failing migration, rewrite, or vendor because "we've already spent six months." The spent months are gone either way; the only question is whether the next month is better spent here or elsewhere. Make the "would we start this today" question a standing agenda item for long projects.

Fetch it as data

This checklist is the Cognitive Biases dataset — usable as a pre-decision prompt insert for agents that advise on plans:

curl "https://yjtoon.com/api/dataset/cognitive-biases?format=toon"

Related: Learning Theories for how teams absorb this material, and verifying LLM output — models exhibit the same biases, borrowed from their training data.