LR Question 21 Explanation
QUESTION TEXT: At a large elementary school researchers studied…
QUESTION TYPE: Weaken
CONCLUSION: Chess made the children smarter.
REASONING: Children in the chess program started getting better grades.
ANALYSIS: This argument presents one possible cause of the higher grades. It wants you to forget that there are other possible causes. The chess program might have increased grades for a reason other than reasoning power or spatial intuition.
The right answer seems like its out of left field, and you might have avoided it for that reason. But “out of scope” is not a useful tool. If something affects the argument, then it’s relevant, even if it wasn’t a term mentioned in the argument.
___________
- So? Take weaken question answers at their weakest. This could mean one single student learned chess outside the program. And we don’t know whether or how it impacted their grades.
- If you picked this, you probably thought “ah, the stupid kids failed to learn chess, and the smart kids did learn. That explains the difference.”
Nope. The issue is not that those who finished the program had higher grades. It’s that their grades improved. So if someone had a C, now they have a B. If someone had an A, now they have an A+.
The relevant comparison isn’t between students; it’s between an individual student’s grades before the program and after. - CORRECT. This provides an alternate reason for the grade increase. The students wanted to be on the chess team, and to do that they needed to improve their grades. So they worked harder or something.
- Who cares? This could mean one student who wasn’t in the chess group improved their grades. That’s normal – students improve their grades all the time for reasons unrelated to chess. This tells us nothing about the chess group.
- So? This could mean a single person who didn’t finish the program was better than one person who did finish. The program could have had 1,000 students. This answer has zero impact.
More Resources for Weaken Questions
- Intro Course lesson: This intro course lesson covers Weaken questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers weaken questions.
“If you picked this, you probably thought “ah, the stupid kids failed to learn chess, and the smart kids did learn. That explains the difference.”
Nope. The issue is not that those who finished the program had higher grades. It’s that their grades improved. So if someone had a C, now they have a B. If someone had an A, now they have an A+.
The relevant comparison isn’t between students; it’s between an individual student’s grades before the program and after.”
A, D, E are all definitively ruled out as wrong, and C is clearly the best option by a wide margin because it provides a clear explanation for the observed effect (“significant increase in achievement levels in all their schoolwork”), but I strongly believe B is also a valid answer, and not for the flawed reasoning offered above.
For this question, what matters is that the answer choice provides an explanation for the observed effect (in the group that completes the program) which differs from the one provided in the stimulus.
B does this by suggesting that these two groups of students have different qualities that may explain observed effect; the significance is not that the smart kids learned chess and the dumb kids didn’t learn chess (as you said it’s not about comparing these two groups, it’s about comparing an individuals pre/post program results) it’s that each group had a different propensity to improve their grades irrespective of the chess program.
Considering there was a significant increase in achievement levels in their schoolwork, the average grade of the students who completed the program cannot be A or there would be no room for significant improvement (you can argue for low A to high A being significant improvement but this is irrelevant).
Logically, then they must have a ~B/C averages at best. It follows that for the students that did not successfully complete the program, (who had lower pre-program scores) we can assume they are ~C/D average or worse.
B tells us that that students in the group that completed the program have some quality that the group who did not complete the program don’t, which could account for the observed effect (and thus undermine the argument in the stimulus); perhaps this program was simply the impetus for these students to become more serious about learning, (through inspiring their curiosity, helping them to gain confidence etc., (irrelevant)) and this is produced the effect we saw, not improved reasoning/spatial intuition skills.
Of course, this is a lot of mental gymnastics and pointless in the context of this question when C is a far superior answer, but I think it’s good to deeply analyze answer choices to improve your understanding.
It’s definitely worthwhile to analyze incorrect answer choices to get better at the LSAT. That said, I don’t agree that B is a valid answer.
1. B doesn’t explain the improvement. The conclusion is that chess caused the improvement in those who completed the program. B talks about a different group and only tells us they had lower grades before. That’s not an alternative cause for improvement (as I’ll discuss in the next point), it’s a background fact about a separate group.
2. Your “propensity to improve” assumption is unfounded. The LSAT allows you to make very reasonable inferences that are supported by the material. This is not. You argue that maybe the successful students improved because they had a higher inherent tendency or motivation to improve. But that’s nowhere to be found in B. B says they STARTEd higher, not that they were on an upward trajectory already or are somehow more self-motivated. All we know is the students who didn’t complete had worse grades before. We don’t know why they didn’t complete, and most importantly, the non-completers grades tell us nothing about the improvement of those who DID complete.
3. The speculation on grades isn’t helpful and doesn’t make B any more valid. As you noted, the averages themselves are irrelevant. It only matters that most of the completers significantly improved. So the non-completers starting off lower has no bearing on someone else’s personal improvement.
Basically, the inference that B tells us that the completers had a greater propensity to improve and this accounts for the actual improvement is unfounded. B doesn’t tell us “that students in the group that completed the program have some quality that the group who did not complete don’t.” That’s you making inferences based off their respective starting grades. But as you noted, comparing starting grades between groups isn’t helpful as we’re trying to weaken a conclusion about personal improvement within a group.
A good rule of thumb is if you’re recognizing yourself that it’s a lot of mental gymnastics, you’ve probably gone too far. I don’t really see anything in B that supports anything about propensity to improve.