LSAT 143 | Section 1 | Logical Reasoning: Q20

LR Question 20 Explanation

QUESTION TEXT: Researchers compared the brains of recently deceased…

QUESTION TYPE: Most Strongly Supported

FACTS:

1. 35% of deceased schizophrenics in the sample had damage to the subplate.
2. None of the non-schizophrenics in the sample had damage to the subplate.
3. This damage must have occurred before the second fetal trimester.

ANALYSIS: The second fetal trimester is before a person is born. The LSAT assumes you have this basic knowledge of anatomy.

So we can say that it seems probable that some people get schizophrenia before birth.

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1. This mixes up the groups involved. The stimulus said that 35% of schizophrenics had damaged subplates.
   It’s possible that 100% of people with damaged subplates will have schizophrenia.
   This answer is like saying “10% of undergrads will go on to study law. So 10% of people who study law will have been undergrads once.”
2. Hard to say. It’s possible that the damaged subplate causes some other damage elsewhere, and it’s that damage that causes schizophrenia.
3. This is an extremely tempting answer, but it’s 100% wrong. The stimulus said that the damage to the subplate occurred prior to the second fetal trimester. This answer says after the second fetal trimester.
   This answer shows why you should read all the answers. E, the correct answer, sounds very similar to this. If you read all the answers, you’d see that both C and E can’t be right.
4. This is not supported. We don’t know why the subplate is damaged before the second trimester. It’s possible that some non-genetic harm to the mother (stress, injury, loss of nutrients) causes subplate damage.
5. CORRECT. This is supported. The fact that no people without schizophrenia had subplate damage is telling.
   Nothing is certain, which is why this answer appropriately says “may”.