Question

If two variables, X and Y, are correlated, what are the possible directions of causality?

(A) X could be causing Y
(B) Y could be causing X
(C) Some third factor could be causing both X and Y
(D) All of these

Answer 1

The possible directions of causality when two variables are correlated are X causing Y, Y causing X, and a third factor causing both X and Y. So the correct answer is Option D.

Step-by-step explanation:

The possible directions of causality when two variables, X and Y, are correlated are:

1. X could be causing Y. This means that changes in variable X could be directly influencing changes in variable Y. For example, if we observe a positive correlation between the amount of studying (X) and exam grades (Y), it is possible that studying is causing the improvement in grades.
2. Y could be causing X. This means that changes in variable Y could be directly influencing changes in variable X. Using the previous example, it is also plausible that higher exam grades (Y) are causing students to study more (X) in order to maintain the high grades.
3. Some third factor could be causing both X and Y. This means that there is another variable, not directly observed, that is influencing both X and Y. This variable is known as a confounding variable. For instance, in our example, it could be that the level of motivation or interest in the subject (confounding variable) is causing both studying (X) and exam grades (Y) to increase.

Therefore, the correct answer is (D) All of these.