This is a Lexicon entry: the mechanism, when it shows up, and the countermeasure. The full correction, with real-world cases and the audit prompt, hasn't been written yet.
When it shows up
Conspiracy theories thrive on this: a president's assassination must involve a grand conspiracy, not a lone shooter. A financial crash must have a mastermind, not a cascade of small failures. Conversely, we underestimate the power of small, compounding causes to produce large effects.
Failure mode
Dismissing simple explanations for complex events. Overcomplicating root cause analysis. Missing the small, unglamorous factors that actually drive outcomes. Searching for proportional villains instead of systemic causes.
Countermeasure
Ask: "Could a small, boring cause produce this large, dramatic effect?" Review cases where disproportionate cause-effect relationships are documented: butterfly effects, cascading failures, compound interest.
Related traps
Also connected in the mapThe Narrative Fallacy·2 more, locked
Read next
Entry #44 of 631 in The Lexicon · see the full Lexicon