LR Question 14 Explanation, by LSATHacks
QUESTION TEXT: Researchers recently studied the relationship between…
QUESTION TYPE: Flawed Reasoning
CONCLUSION: You’ll be less depressed if you eat less chocolate.
REASONING: There is a correlation between chocolate and depression.
ANALYSIS: It’s essential you understand why correlation doesn’t lead to causation. There are always four possibilities:
- Chocolate causes depression.
- Depression causes chocolate eating.
- Some third factor (e.g. stress) causes both depression and chocolate eating.
- It’s a coincidence.
We can never say that correlation leads to causation. Correlation just means two things occur together. Any of the four things above are possibilities.
___________
- The “improperly infers” part of this answer is right. But the rest is wrong. The argument didn’t prove that chocolate “causally contributes” to depression. If chocolate did causally contribute to depression, this would be a good argument!
- This is a different flaw.
Example of flaw: Those with a chocolate allergy had less depression when they stopped eating chocolate. So everyone is likely to have less depression when they stop eating chocolate. - CORRECT. This describes a causation-correlation flaw. Remember, the fact that two things happen together doesn’t mean that one causes the other.
- This is a different error.
Example of flaw: If John was planning to murder me, then John would live in the same city I do. John does live in the same city I do, so he must be planning to murder me! - This is a different flaw. I’ve actually never seen this on the LSAT, though it may exist as the correct answer on some older tests. The flaw would basically be that the conclusion is so unclear that we can’t judge if it’s correct. But this conclusion is very clear: less chocolate = better mood.
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Quick comment on (A):
I think the author draws a conclusion that there is a causal relationship, so that’s not the reason why to eliminate (A). There are two wrong things:
– The author does not say the chocolate reduction would eliminate depression, just that it would improve their mood.
– Even if, it is not improper to infer that a reduction of the cause is likely to cause a reduction in the effect. If foxes are hunting chickens in a village, it is not improper to say that if there is a way to prevent the foxes from coming into the village the chicken population will stop decreasing.
The author concludes that the relationship is causal, but they didn’t establish it in their reasoning. A says they “infer FROM a causal relationship”. This means they take a causal relationship in the reasoning and infer the conclusion from that.
It’s very subtle language, but it’s crucial to notice which section of an argument an answer refers to.
Note: This is an old comment but I wanted to clarify the point.