Build a mind you’re proud of.
Correlation is a clue, not a cause
Two things can move together without one producing the other.
The idea
A third variable may influence both, the direction may be reversed, or the pattern may be coincidence. Causation needs a mechanism and stronger evidence.
An example
Ice-cream sales and sunburns rise together because hot, sunny weather increases both—not because ice cream causes sunburn.
Put it into practice
When you see a correlation, search for hidden variables and ask what experiment could separate the explanations.
Test yourself: A survey finds that people who own running shoes sleep better. What can you conclude from the survey alone?
The two are associated; other factors may explain it
Association alone does not establish direction or causation. Exercise habits or other factors could influence both.
Explanation and illustrative examples by One Card Wiser. Source linked for further reading.
Open this card in the app →