Question

if two things are correlated, does that mean one thing is causing the other to happen?

Answer 1

No. Correlation means, with change in one variable, the corresponding change in the other variable is predictable. It can either be positive or negative. But that doesn't mean that one causes the other. The actual cause of the correlation might be explained by some other variable, which is called the confounding variable or the lurking variable. For example, consider the number of ice cream sales and sunscreen sales. We find that as the number of sunscreen sales increase, ice cream sale also increases. This does not mean that suncreen sale is the cause of increase in ice cream sale. The confounding variable here is the temperature. As the temperature increase, people tend to buy more sunscreen and also they tend to eat more ice cream. So, correlation means, sometimes one variable causes the other, but not in all cases. In some cases, a confounding variable can be the causative factor.