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.
Causal errors
Fallacy of the single cause
Also called Causal oversimplification
In depth
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.