# Does correlation correlate with causation?

Correlation does not imply causation, but causation causes correlation. By correlation I do not mean exclusively linear correlation, it could be arbitrarily shaped, as long as it is consistent and reflects dependency.

Does correlation correlate with causation?

At first I thought: "Yes, because every causation implies correlation hence there definitely is a correlation between correlation and causation."

But then I thought: "Wait, the answer is no because for every correlation that is truly causal there are an infinite number of correlations that are not causal, hence the correlation between correlation and causation is not significant."

Which is right, the first answer or the second answer? Or neither?

• Causation does not imply correlation because the causal relationship might be nonlinear. Aug 25, 2017 at 15:58
• I reworded the question to state that by correlation I'm not referring to linear relationships exclusively. Aug 25, 2017 at 16:06
• You still need to define what exactly you mean by correlation. Because if you make your definition too wide or vague, it won't be different from causation. If you say "any kind of relationship" that's basically wide enough to include causation. Aug 25, 2017 at 17:50
• Doesn't this boil down to a tautology? "Correlation implies correlation". Aug 26, 2017 at 0:31
• You’ve applied the word “correlation” to two concepts without measurement, which makes this question hard to interpret. By “does correlation correlate with causality,” do you mean do people infer causality when they infer correlation? Do you mean that research on causality or correlation tend to come from the same people? Do you mean that if you create a dataset of literally every bivariate relationship that exists or will ever exist, if it is correlational, is it also likely causal? Nov 8, 2017 at 15:15

The sentence "correlation does not imply causation" is usually understood much broader than it should be. If two variables A and B are highly correlated, then something is causing something else. You just cannot conclude that A causes B because there are a number of other possibilities:

• B causes A
• A and B are both caused by C
• Only if D is given, does A cause B
• A causes E which in turn causes B
• (An error of type I occured and the correlation is not significant, but this one is dealt with by talking about strong correlations.)

Does correlation (any statistical association) correlate with (related to) causation?

This question (words in parentheses are mine) is quite general and essentially the answer seem me yes. Causal inference in statistics framework exist exactly because the answer to that question is yes. However in order to give more useful answer we need to better specified question. The following question seem me the best:

Does causation imply correlation?

Does causation imply correlation?

others related questions are:

Under what conditions does correlation imply causation?

Statistics and causal inference?

Regression and causality in econometrics

Correlation is a special type of association and association is different from causation which can be only inferred from a randomized experiment(the reason would be the confounder).

References:
1. Association and Correlation
2. Openintro-Statistics