Logical reasoning PrepTest 121 · Section 4 · Question 11

Incorrect. The argument concludes that two things aren't causally related, not that a supposed causal relationship is reversed, as this answer states.

Incorrect. The Psychiatrist argues that trauma doesn't cause phobias, but she doesn't say that they therefore have no cause.

Incorrect. This answer describes a circular argument, but the Psychiatrist uses examples/counterexamples to prove her point, so that flaw isn't present here.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
First appearances of phobias usually come after trauma
Consideration 1 - Some people who go through trauma don't develop phobias
Consideration 2 - Some people with phobias haven't gone through trauma
Conclusion - Trauma isn't a causal factor in phobias

Answer Anticipation:
This argument is an interesting twist on causal arguments that can teach us something about that type of logic.

The conclusion here is that trauma isn't a causal factor in phobias, despite the strong correlation between the two (phobias usually appear after trauma). Why does the Psychiatrist believe that the two aren't causally related despite the strong correlation? Because the correlation isn't 1:1—there are people with the cause but without the effect, and with the effect but without the cause.

While counterexamples are sufficient to show that a certain causal relationship isn't certain—that one thing doesn't always cause another—it's not enough to show that the supposed cause isn't a causal factor in the effect. As a parallel example, think about smoking. It definitely causes lung cancer, even though there are people with lung cancer who have never smoked and lifelong smokers who don't develop lung cancer.

So this argument is flawed because it assumes that something either always leads to a given outcome, or it's not a causal factor in that outcome at all.

Answer Explanation:
This answer choice describes the flaw in the Psychiatrist's argument. She uses some counterexamples to argue that two things aren't causally related despite there being a strong correlation between them. That assumes that if something doesn't always cause a certain outcome, it's not a causal factor in it—or, in other words, that one thing causes another only if the two are invariably (i.e., always) correlated.

Key Takeaway:
This argument highlights why counterexamples can't be used in Weaken questions that feature a correlation/causation flaw where the causality isn't absolute. One thing can be a causal factor in a given outcome even if it doesn't always lead to that outcome. Sometimes, one thing tends to cause another, in which case the correlation will be weaker than 1:1.

Incorrect. The conclusion is that one thing doesn't cause another, so the Psychiatrist isn't deriving a causal connection at all—she's ruling one out.