Fallacies: T (Part 2 of 2)

Core idea

The second half of T runs from television and turkey to the elegant "top-hat fallacy" — the cleanest illustration in the whole book of why correlation is not causation. Around it sit debunked national heroes, the tidy but false left-brain/right-brain split, and a turkey wrongly blamed for post-dinner drowsiness. The unifying skill is asking what else could explain a pattern before crediting the obvious cause.

Why it matters

The top-hat fallacy deserves its fame: tall people do wear top hats more often, but the hidden cause is income, not headgear. Once you can name a lurking variable, half the bad arguments you meet — about food, brains, gadgets — fall apart. The other entries here show the same principle from different angles.

Key takeaways

Mental model

Copy sourceZoom

Practical application

When two things move together, resist the first explanation and ask: is there a third factor driving both? Income drives both height and top hats. Carbohydrate-heavy meals drive both turkey consumption and drowsiness. Naming that lurking variable is the single most useful habit in this topic.

Example

A study reports that people who drink coffee live longer, and a headline credits the coffee. Run the top-hat check: coffee drinkers may also be wealthier, more socially active, or better resourced for healthcare. Until those lurking variables are controlled, the coffee is just wearing the top hat.

Related lessons