Q24 - Pediatrician: Swollen tonsils give rise to breathing

[smiller]

Question Type:
Flaw

Stimulus Breakdown:
Premise:
1. Swollen tonsils cause breathing problems during sleep.
2. Removing children's tonsils alleviates sleep disturbances.

Conclusion:
Removing children's tonsils before swelling occurs will guarantee that they do not experience breathing problems while sleeping.

Answer Anticipation:
There are a few problems with this argument:
1. The first premise states that swollen tonsils cause "breathing problems," but it doesn't state that they cause all breathing problems that children experience during sleep. Some breathing problems might have other causes.
2. We don't know if removing tonsils before they swell has the same effect as removing them once they are swollen.
3. Removing swollen tonsils alleviates sleep disturbances, but we don't know if this means that removing them alleviates breathing problems. The sleep disturbances in the second premise could be related to the breathing problems in the first premise, but we don't know for certain that this is the case.

Correct Answer:
(E)

Answer Choice Analysis:
(A) This is not a flaw in this argument. The pediatrician doesn't cite a source, so we have no idea whether or not the premises are based on an inappropriate authority.

(B) This is not a flaw in the argument. It's tricky, because it's vague. If an argument assumed that someone frequently makes untrue statements, then concluded that he is a habitual liar, this answer choice would apply. That's not what's happening in this argument.

(C) This is not a flaw in this argument. The argument doesn't conclude (infer) anything about what is intended. The conclusion is about the actual result, regardless of intention.

(D) "Other medical reasons" are irrelevant. The conclusion is about the result of removing children's tonsils, regardless of the reason.

(E) This is the correct answer. It highlights the first problem with the argument that we identified above.

Takeaway/Pattern: Don't immediately eliminate an answer choice that is vague or worded abstractly, but don't pick it just because you don't understand it. See if there is another answer choice that more accurately describes the flaw in the argument.

#officialexplanation

[judaydaday]

This may be a little random..

Is it correct to translate "ensure" as a sufficient condition? For some reason I always thought that "ensure" indicates a sufficient condition.

[tommywallach]

Yep! Good point.

-t

[andrewgong01]

"If an argument assumed that someone frequently makes untrue statements, then concluded that he is a habitual liar, this answer choice would apply. That's not what's happening in this argument"

I am still confused as to what "B" really means on the LSAT. I was really tempted by "B" because the way I see this problem is that the huge assumption is that tonsils are the only cause of sleeping problems. We have to assume that for the argument to be valid. So it just seems like "B" seems correct too

[isacatty]

"If an argument assumed that someone frequently makes untrue statements, then concluded that he is a habitual liar, this answer choice would apply. That's not what's happening in this argument"

I am still confused as to what "B" really means on the LSAT. I was really tempted by "B" because the way I see this problem is that the huge assumption is that tonsils are the only cause of sleeping problems. We have to assume that for the argument to be valid. So it just seems like "B" seems correct too

B is saying that the argument commits the flaw of circular reasoning. If the argument proceeded by circular reasoning, then the premise would basically have to be a restatement of the conclusion. The argument's conclusion is not a restatement of any of its premises, explicit nor assumed.


I want to elaborate on why C is not the right answer choice (so I hopefully never make this mistake again). From smiller: "(C) This is not a flaw in this argument. The argument doesn't conclude (infer) anything about what is intended. The conclusion is about the actual result, regardless of intention." I don't agree that the argument doesn't conclude anything about what is intended, technically. I would say that the argument does conclude that the intention of removing tonsils surgically is so that children do not experience any breathing problems.

However, if the argument committed the logical flaw that this answer choice describes the argument would have to conclude a consequence or an effect was intentional when it may not have been. I don't have a great example for this flaw, so if anyone else does, please share!

This question is a tricky one though, especially if you've only got a couple minutes left for the section. C is the most commonly chosen wrong answer choice (B is second), and I think if you're doing it quickly, it can appear to fit the stimulus:

The first part can be substituted like so:
(C) infers from the fact that an action (surgical removal of swollen tonsils) has a certain effect (shown to alleviate sleep disturbances)...

But the second half is where it goes wrong:
... that the action (surgical removal of tonsils before swelling) is intended to produce that effect (no breathing problems during sleep).

The conclusion doesn't match up. Even though I don't think it's a completely unjustified leap to assume that breathing problems during sleep would reasonably constitute sleep disturbance, and I don't necessarily believe that kind of assumption is what the LSAT would punish you for, I see that it doesn't match up to the information provided and it's not even the flaw (if you understand the meaning of that answer choice) committed in the argument. Now, I really don't even know why I picked it over E.

Here are two other answer choices that describe the same flaw:
- The argument infers solely from an effect produced by an action that a purpose of that action was to produce that effect
- The argument draws a conclusion about the intentions of a group of people based solely on the consequences of their behavior

[andrewgong01]

Isn't circular reasoning defined as restating the truth of the premise as the conclusion (or at least the way its defined in other questions on the LSAT) ? Relies on an assumption tantamount to assuming the conclusion is true does not seem to imply you are assuming what you seek out to prove where the premise=conclusion. Here it seems more like the answer choice is saying the conclusion hinges on a huge assumption which is needed for the argument to hold and not the author has pre-supposed the truth of the claim.

[ohthatpatrick]

Annoyingly, CIRCULAR REASONING is described in two pretty different ways:

the conclusion is a restatement of the premise

or

assumes what it sets out to prove
presupposes what is seeks to establish

If there's any meaningful difference to care about there, I guess the first is more explicit:

the conclusion is a restatement of the premise
Chocolate is the best. After all, nothing is as good as chocolate.

vs.

assumes what it sets out to prove
presupposes what is seeks to establish
Chocolate is the best. After all, people who think vanilla is better are clearly wrong.