In the previous two posts, we saw how Weaken-Type Critical Reasoning questions based on correlation-causation passages can be solved in under a minute. Just to summarize, X and Y are correlated does not mean X is causing Y since there is no evidence to prove that the direction of causation is from X to Y, it can also be from Y to X So based on arguments that conclude that X is causing Y since X and Y are correlated, Assumption and Strengthen questions can also be asked. Assumption Type: The assumption is that Y is not causing X. A researcher discovered that people who have low levels of immune-system activity tend to score much lower on tests of mental health than do people with normal or high immune-system activity. The researcher concluded from this experiment that the immune system protects against mental illness as well as against physical disease. The researcher’s conclusion depends on which of the following assumptions? (A) High immune-system activity protects against mental illness better than normal immune-system activity does (B) …