Ha, hm!! Let's say A and B are two things that may be true or false, with some probability. If A and B are not independent, then the probability of A is changed by knowing B, and vice versa. The probability of A, if you know B, is not the same as the probability of B, if you know A; to get from one to the other, multiply it by the ratio of the probabilities of the thing given to the thing unknown. The ratio of the probability of A given B to that of B given A equals the ratio of the probability of A to that of B. When A and B are similarly probable, the probabilities of each given the other will be similar. But when A is much more probable than B, then the probability of A given B is much greater than the probability of B given A. So even if A and B are correlated, then knowing A is true shouldn't give you much confidence that B is also true.
Sensitivity and Specificity (sketch) | Toph Tucker | Observable