What can use to extrapolate a cause-effect relationship between 2 variables?

#1
Let's assume that I have found a correlation or an association between two variables.
  1. How can I find out if there is cause-effect relationship between the 2 variables?
  2. question: The difference between an association and a correlation?
  3. A strong association automatically implies a correlation?
 

Karabiner

TS Contributor
#2
How can I find out if there is cause-effect relationship between the 2 variables?
This is either a matter of the study design (e.g. experimenta manipulation), or of strong theory and enough data (e.g. to adjust for confounders).

With kind regards

Karabiner