Usually, when X causes Y that means that X is correlated with Y. This may seem obvious simply because correlation is simply a measure of the extent to which Y goes up, on average, when X goes up. But, fascinatingly, there are some special cases where you can have causation WITHOUT correlation. Here are five ways causation without correlation can occur: 1. Averaging: increasing A sometimes causes increasing B, but other times, it causes B to decrease. The two balance out. Since correlation...