# Fallacy of the single cause

*Also called: Causal oversimplification*

- **Cluster:** Causal errors — Sequence, coincidence and hindsight read as cause
- **Page:** https://fallacy.wiki/fallacy/single-cause/
- **In Arabic:** https://fallacy.wiki/ar/fallacy/single-cause.md
- **Licence:** CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/

## What it is

Reducing an outcome with many contributing causes to just one.

## In the wild

> The project failed because of the vendor.

## How to answer it

List the other contributing factors and ask how much each one moved the outcome.

## Origin and naming

Catalogued in logic texts as 'causal oversimplification' or 'reduction': mistaking a single contributing factor for the whole cause. It travels well because one named villain is easier to repeat in a headline than a chain of conditions.

## More places it shows up

- Crime rose because of the new prosecutor — never mind the economy, the police budget, or the reporting changes.
- The company's decline has one author: the CEO. Not the market shift, the debt load, or the decade of under-investment.
- Obesity is a willpower problem. Full stop.
- Traffic is bad because bikes were given lanes — said about a corridor where the population doubled in ten years.

## How to spot it

- The explanation arrives with one name and a full stop — 'it's X, period.'
- Offering a second cause is treated as defending the first one.
- The story is told with a villain or a hero, never with proportions.

## Nearby

- [Post hoc ergo propter hoc](https://fallacy.wiki/fallacy/post-hoc.md)
- [Correlation implies causation](https://fallacy.wiki/fallacy/correlation-causation.md)
- [Cherry picking](https://fallacy.wiki/fallacy/cherry-picking.md)

## Read more

- [Wikipedia](https://en.wikipedia.org/wiki/Fallacy_of_the_single_cause)

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From fallacy.wiki — a bilingual field guide to 91 logical fallacies, published by phi holdings. Licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/): reuse freely with attribution to fallacy.wiki.