Logical reasoning PrepTest 119 · Section 4 · Question 23

Correct. Argument or Facts:
Argument

Valid or Flawed:
Valid

Question Type:
Parallel Reasoning

Stimulus Summary:
Correlation - Those who exercise vigorously are sick less
Conclusion - This doesn't prove vigorous exercise causes you to not be sick
Why? - Exercising vigorously depends on being healthy

Answer Anticipation:
This argument is an interesting twist on a common logical fallacy present on the LSAT—the Correlation/Causation flaw.

In general, arguments on the LSAT will commit a flaw. This argument, however, brings up a correlation and then concludes that it doesn't prove causality. As such, we should look for an answer that similarly avoids committing the Correlation/Causation flaw, instead pointing out that you can't validly reach a causal conclusion from a correlation.

However, it's likely that multiple answers will fit that mold. Why? Because the argument has a premise that presents a specific reason to not make the jump to causality, and so we will likely need to distinguish between answers that point out different reasons for rejecting that jump. In this specific case, the argument brings up that the potential cause (vigorous exercise) actually depends in part on the effect (health). As such, this brings up a bit of reverse causality, and so we should look for an answer that does the same.

Answer Explanation:
This answer flips the order of the elements around a bit, but it ends up having the same logic as the stimulus. It has a correlation—habitual readers "tend to" be verbally skilled. It then concludes that this doesn't allow it to be concluded that reading causes strong verbal skills because the supposed cause—reading—depends in part on the effect—having strong verbal skills. The argument points out that correlation doesn't equal causation because the reverse causal relationship is also possible, so this is the correct answer.

Key Takeaway:
When Parallel Reasoning questions deal with Correlation/Causation issues, it'll frequently be the case that you'll need to identify specifically what type of Correlation/Causation issue is present.

Incorrect. This answer has more elements than the stimulus, talking about both musical and mathematical skills, so we can rule it out.

Incorrect. This argument doesn't establish a correlation, so we can rule it out.

Incorrect. This is a very tempting answer, but step back from a second and think about the causality the argument says we can't conclude—height causes basketball skills. For there to be an element of reversed causality here, this would have to bring up the possibility that basketball skills cause a child to get tall. That's ridiculous, and it's not what the argument does. Instead, this argument brings up the possibility of indirect causality—being tall causes the children to play more basketball, and that causes the children to get better at the sport. That's different from arguing that the reverse relationship holds, so we can rule this answer out.

Incorrect. There's no reversal of the causality here, and the conclusion is in fact that the diseases have different causes, which doesn't mesh with the stimulus at all.