Q2 - Tall children can generally reach...

[alexg89]

Can someone explain why this is d and not b? I'm not sure what is supposed to be the correlation.

The conclusion says "if short children are taught to reach high shelves easily the proportion of them who become short adults will decrease. "

It seemed to me like they are presupposing this without any proof which is why I selected B. I'm guessing that they are saying that the correlation is that tall children can reach high shelves easily and short children cannot so it must be for this reason that they don't become tall adults. This argument makes no sense and I feel like that conclusion wasn't following because it was supported with irrelevant evidence and therefore was assuming a conclusion without proving it.

[timmydoeslsat]

Can someone explain why this is d and not b? I'm not sure what is supposed to be the correlation.

The conclusion says "if short children are taught to reach high shelves easily the proportion of them who become short adults will decrease. "

It seemed to me like they are presupposing this without any proof which is why I selected B. I'm guessing that they are saying that the correlation is that tall children can reach high shelves easily and short children cannot so it must be for this reason that they don't become tall adults. This argument makes no sense and I feel like that conclusion wasn't following because it was supported with irrelevant evidence and therefore was assuming a conclusion without proving it.

The bolded part is exactly right. Why is it the case that short children are more likely to be short adults than tall children are? There could be several reasons for this. One coinciding factor along with the height difference is that taller children reach high shelves more easily than the shorter children. Will fixing that factor cause the proportion of short children that become short adults to change? We have no proof of that.

Presupposes what it sets out to prove = circular reasoning. This type of reasoning is when we state a conclusion that is the same as a stated premise, which is to be assumed true, which is exactly why we call it presupposing a conclusion that you believe is already true in the argument.

This did not occur in this argument. Our conclusion is never mentioned in the evidence.

[dhlim3]

What a dumb question. It came down to B & D for me. My gut pointed me to choice D but my brain kept telling me that D made no sense what so ever, so I ended up picking B because it at least sounded better.

My thought process for B was:

"If children are short, they cannot reach high shelves. So if they can reach high shelves, they will not be short"

Seemed like a circular reasoning to me, which is why I picked B.

[christine.defenbaugh]

Thanks for posting, dhlim3!

I'm afraid there's a critical mistake in your paraphrasing of the argument.

"If children are short, they cannot reach high shelves. So if they can reach high shelves, they will not be short as adults"

Circular reasoning occurs only when the argument relies on the same information in the premise as it seeks to prove in the conclusion. In this argument, the premise gives a relationship between short children and high shelves. The conclusion shifts the conversation to a conclusion about whether those kids will be short ADULTS.

The most important thing to learn about circular reasoning on the LSAT is how to recognize when it isn't happening. It pops up constantly as a trap answer on Flaw questions, and is only quite rarely a correct response. In arguments that are guilty of circular reasoning, you generally won't feel that a conclusion is utterly absurd (as it is in this stimulus). Instead, you'll often think "wait, didn't they just say the same thing twice?"

Here, the conclusion is categorically insane. The premises all seem rather tepid and realistic, so there has to be some nutty reasoning the author is using to get from one to the other. The challenge in questions like this is actually that the reasoning is so horrifically screwed up, that it's hard to know where to begin. Our brain just screams "OMG, SO WRONG!" at the conclusion, which isn't terribly helpful. Elimination is a very useful strategy here, but if that fails you, try to figure out what bizarro thing the author would have to believe in order to make the conclusion remotely possible.

PREMISES:
1) Short kids often have trouble reaching high shelves.
2) Tall kids often reach high shelves easily.
3) Short kids are more likely than tall kids to become short adults in the future.
CONCLUSION: If short kids could reach high shelves, that would cause them to be less likely to be short adults in the future.

Approach #1: Elimination

(A) No individuals are mentioned - ever.
(B) Conclusion is not identical to a premise - not circular reasoning.
(C) No 'exceptional case' is mentioned.
(E) No 'lack of evidence' is mentioned, nor does the author claim some state of affairs can't exist.

Even if we didn't fully understand (D), we can see that a number of correlations pop up in the premises: one group generally does blah, another group generally does bleh, and this group is more likely than that group to yadda yadda. Those are all correlations. And the conclusion seems to say that the high-shelf-reaching-teaching would cause the kids to be less likely to be short adults!

Approach #2: Justify (D)

Okay, let's start with the crazypants conclusion. What the heck would the author have to be thinking to claim that this high-shelf-reaching-teaching would actually make kids taller adults?!

Well, the premises tell us who is more and less likely to become short adults. The only way to make a short kid less likely to become a short adult would be to transform him/her into a tall kid. Whoa. Okay. Soooo....the author believes that the high-shelf-reaching-teaching will actually make short kids into tall kids.

Why would this author believe that? Well, we know that being a short kid is correlated with having trouble reaching high shelves. Maybe this author believes it's the 'having trouble reaching high shelves' that is actually making the kid a short kid. If that's true, then fixing that problem would PRESTO CHANGO make the kid a tall kid.

Clearly, that's insane. But that's what this author has to be assuming: that having trouble reaching high shelves is the cause of a kid's shortness. Since the premise only gives a correlation between the two things, this bizarre assumption matches (D) perfectly.

Elimination is way, way easier here than trying to completely justify (D). It's important to get comfortable with accepting a weird answer that you don't 100% get, if every other answer choice has been categorically eliminated. After all, as Sherlock Holmes would say, "when you have eliminated the impossible, whatever remains, no matter how improbable, must be the truth."

Please let me know if this helps clear up a few things!