What’s the difference between correlation and causation?

In the correlation–causation fallacy, a perceived similarity or relationship between two variables is wrongly assumed to imply a cause-and-effect relationship. It’s important to understand the differences between correlation and causation:

  • Correlation: variables change together or share common characteristics
  • Causation: one variable, event, or phenomenon directly leads to another

The maxim “correlation does not imply causation” is often used to rebut the correlation–causation fallacy. Observing a similarity or relationship between two variables does not necessarily indicate a causal link.