What distinguishes a strong causal claim from a correlation?

• A. Correlation shows a direct influence without any evidence is needed.
• B. Causation can be claimed from a temporal sequence alone without supporting mechanism.
• C. A correlation and causation are interchangeable terms.
• D. Causation requires evidence of a direct influence and a plausible mechanism; correlation shows association, not causation.

Answer: (D)

The main idea is that a strong causal claim is about one thing actually producing a change in another, not just happening to be linked. To claim causation, you need evidence that altering the supposed cause leads to a change in the effect (often shown through experiments or solid causal-inference methods) and a plausible mechanism that explains how the change occurs. Correlation, by contrast, only shows that two variables move together; it says nothing about direction or why the change happens, and it can be explained by a third factor, reverse causation, or random chance. So, causal reasoning combines a direct influence with a believable mechanism, while correlation is simply an observed association.