by ohthatpatrick Fri Feb 12, 2016 2:42 am
Thanks for bringing this to the forum!
Both #15 and #16 here relate to a classic LSAT reasoning template:
CORRELATION to CAUSALITY.
The 1st guy points out a CORRELATION between
"working a lot of part time hours" and "lower grades".
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typical correlation language:
X is associated with Y
People who are X are more likely to be Y
People who are X tend to be Y
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When you hear that correlation wind-up, get ready for some presumptively causal conclusion.
1st guy concludes,
"working lots of part time" [caused] "lower grades"
Whenever LSAT gives us this template, we say a few things:
1. Could just be a coincidence (but most correct answers don't go that direction)
2. Could be happening in reverse (if we don't know which half of the correlation came first, it's hard to judge cause and effect)
3. Something else is the cause. These two correlated things might just be mutual symptoms of some third thing.
When the 2nd guy says "Not so ... the bad grades came FIRST and then the students set out to earn as much money to compensate", he's giving us #2, Reverse Causality.
And then in #16, (C) is getting at the same issue. In order to assess whether a correlation between X and Y means that X causes Y, at a minimum we want to be sure that X came first, and THEN Y.
If Y came first, then clearly X wasn't the cause.
(C) is saying, "if these high school students ALREADY had these bad grades, and THEN got part time jobs, then clearly we can't blame the bad grades on the part time jobs. Meanwhile, if they were relatively free of academic problems, started working part time, and NOW have academic problems, then I'm more persuaded that the part time work is degrading their GPA."
Does that make sense?
=== other answers ===
(A) Later career success is out of scope. We're just debating the claim of Did / Didn't getting a part time job hurt the grades of these students?
(B) This is pretty out of scope. If it were honing in on the idea of a student NOT ONLY working BUT ALSO doing sports/extracurriculars, we can see how such a busy schedule is relevant to getting bad grades. But this is only talking about whether students are ALLOWED to do extracurriculars. Answering that question tells us so little.
(D) We are only debating whether THESE students had their grades hurt by taking on part time work. It's irrelevant whether SOCIETY typically acts that way.
(E) This may seem to give us a fuller picture of what the future holds for these part time working students, but we are only debating whether their CURRENT academic performance has been hurt by CURRENTLY working part time.
Hope this helps.
The correct answer to (B)