Logical reasoning PrepTest 149 · Section 3 · Question 5

Incorrect. This answer raises an alternative potential cause, thus weakening the argument.

Incorrect. This answer suggests that the causation assumed in the second premise reverses the real relationship, thus weakening the argument.

Incorrect. The stimulus discusses the rate of Alzheimer's in India ("incidence"), so it takes population into account and thus this answer has no effect on the argument.

Incorrect. If the conclusion were about curcumin, then this answer might raise an alternative potential cause. However, the conclusion is about turmeric, so other compounds in turmeric that might fight amyloid buildup wouldn't affect the argument in the least, so failing to look for them won't, either.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
India eats a lot of turmeric and has low Alzheimer's rates. Also, those with Alzheimer's have a lot of amyloid, and turmeric reduces amyloid levels. Therefore, turmeric probably helps to prevent Alheimer's.

Answer Anticipation:
Arguments that discuss cures for diseases are inherently causal, and they almost always feature a correlation/causation flaw, so that's where we should start here.

Are the premises causal? Yep. First, a low Alzheimer's rate is correlated with high turmeric consumption in India. Second, the amyloid is also correlated with Alzheimer's—it's not established that it causes it or makes it worse, just that it's present there. Maybe Alzheimer's itself causes the accumulation of amyloid—in other words, maybe Alheimer's causes amyloid levels to rise instead of the reverse.

Since this argument bases a causal conclusion on correlations, and we're tasked with strengthening it, we should look for the common answers for this pattern:

(1) Eliminate an alternative cause
(2) Bring up more examples of the cause and effect going together
(3) Bring up a control group (no turmeric; high Alzheimer's rate)
(4) Explain how the causality works (note that the argument tries to do this in the discussion of amyloid proteins, but it fails to establish causality there)

Answer Explanation:
This answer strengthens the correlation between turmeric and lowered rates of Alzheimer's, thus increasing the likelihood of a causal connection. While correlation doesn't prove causation, it does support it!

Key Takeaway:
Remember that correlation doesn't prove causation, but it does support a causal relationship. As such, causal relationships can be strengthened by answers that establish more or stronger correlations between the suggested cause and the effect.