Q14 - What criteria distinguish addictive

[ManhattanPrepLSAT1]

Most of the stimulus is not relevant; the first sentence poses a question, the second sentence provides a claim that some have suggested, and the third sentence explains why those people in the second sentence are incorrect. It’s not until the final sentence that we get anything really solid. The correct answer will probably just replicate the information in the final sentence in new terms.

(A) has two complicating issues. First, the answer choice mistakes necessity for sufficiency. The stimulus relies on the phrase "only if", whereas the answer choice relies on the word "if." And second, it’s not about one person having difficulty ceasing to use a substance, it’s about a majority of people having difficulty.
(B) is tempting, but we don’t know how many substances fall into the addictive category using the various definitions.
(C) is correct. It says that a substance is addictive only if it is difficult for most users to quit. This is directly taken from the final sentence.
(D) is irrelevant. It’s not about use that makes something addictive. It’s about difficulty in quitting.
(E) Is not quite true. The author challenges one definition of addiction, but doesn’t imply that a definition isn’t possible.

#officialexplanation

[weiyichen1986]

I have a question for B,

If we already know that more additive substance will be deemed nonadditive category if we use sole criterion, then isnt it true fewer substances will be deemed additive if we use a "adequate" definition?

Why do we have to think about the actually numbers?? i thought we just have to make a comparison????

can someone please help me......Thank you so much!

[ManhattanPrepLSAT1]

Thanks for bringing up answer choice (B) again. I can see that the explanation for this one is actually more interesting than I first gave it credit for.

Notice that under the system the author believes is inadequate, we see that all a substance needs to be considered nonaddictive is for some people to cease use of. Under the adequate system, substances won't get such an easy pass. Now if it causes the majority of folks discomfort during the cessation process, it will not be considered addictive.

So answer choice (B) represents something we would expect to be false! It's the opposite of what we want.

Does that answer your question?

[vlstewar]

So, I'm confused because I think the last line states that the adequate definition of an addictive substance is one where the user DOES experience discomfort during their withdrawal? Thus, answer B, which is based on the more restrictive "adequate" rule would then exclude substances that did not cause people discomfort.

[sumukh09]

So, I'm confused because I think the last line states that the adequate definition of an addictive substance is one where the user DOES experience discomfort during their withdrawal? Thus, answer B, which is based on the more restrictive "adequate" rule would then exclude substances that did not cause people discomfort.

Hey

We don't actually know what the expert feels about how this new adequate criteria he mentions in the conclusion would impact the number of substances that are deemed addictive. Notice that after the "however" he says if we use the criteria that some have suggested (as described in the preceding sentence) then some addictive substances would be nonaddictive. The expert is actually arguing AGAINST this criterion so we can't infer B since the adequate criterion is the one he suggests in his conclusion as opposed to the one advanced by "some" in the first sentence. Moreover, the criterion after the "however" is actually inadequate and not adequate.

[sumukh09]

C is worded strangely with the modifier "some" in the sufficient condition and the "not true for most" in the necessary condition. Slick move by LSAC

[zip]

I have a question for B,

If we already know that more additive substance will be deemed nonadditive category if we use sole criterion, then isnt it true fewer substances will be deemed additive if we use a "adequate" definition?

Why do we have to think about the actually numbers?? i thought we just have to make a comparison????

can someone please help me......Thank you so much!

We have no way of knowing what the standard is at present, so B can't be right. There were only two standards given and neither was averred to be the present standard. So while it's tempting to think that we should make a comparison between the two, it is not supported by the stimuli.

[samuelfbaron]

Is (C) simply the contrapositive of the final sentence?

[carlin.odonnell]

Is (C) simply the contrapositive of the final sentence?

Not the contrapositive - it is actually the same logic...

Last sentence: If addictive --> withdrawal causes most habitual users extreme psych and phys difficulty.

Answer C says the same thing in a tricky way: If addictive --> not true for most users (where the "not true" is the first part of the answer: some habitual users experience no psych or phys difficulty).

aka C = If addictive --> most habitual users DO experience extreme psych and phys difficulties.

[james.h.meyers]

I might have made a rookie mistake on this one, but I'm hoping someone can help out.

I picked (C) initially, but then when reviewing (before grading) I crossed it out and picked (E).

(C) I felt would be correct from the Expert's view, but he specifically says not everyone agrees, (and it is from the experts statements that we are supposed to infer). Ultimately if the Q-stem is asking what must be true based on the statements, (I know it says "properly infer" but I take that to mean must be true), then no statement of fact - of what is addictive should be correct, (it seems). After all, the only guaranteed thing in the stimulus is that people don't agree on what defines "addictive."

The author is saying that some people say Addiction is defined as X while others define it as Y, I think any adequate criteria must contain Z.

What must be true? I cannot see how (C) is correct unless it started with, "The Expert believes that a substance..."

Also I wouldn't say that (E) is attacking any premises because the whole stimulus is the expert saying some believe this, whereas I believe that.

So, as I said, perhaps this was a rookie mistake - perhaps "impossible" is too strong - but I'm wondering if I should be looking at inference questions differently when they are a person's opinions, or if there is some other mistake I'm making.

thanks

[T.J.]

Despite the fact that it is the right answer, Answer C is not really airtight. "That is not true" refers to the first part of sentence, which after negation will read "Most habitual users CANNOT cease to use with little or no psychological or physiological difficulty" (most habitual users quit with more than little or no difficulty). is this the same as "withdraw from its habitual use causes most users EXTREME..."?

No, more than little or no difficulty does not have to be extreme difficulty. There can also be medium-level pain. Not that it's either little or extreme.

Thoughts?

[rinagoldfield]

Awesome conversation above! In terms of the formal logic of the last sentence and (C), we can translate the last sentence like this:

If addictive --> most habitual users who try to quit will suffer extreme difficulty

That’s from the stimulus. Then, (C) muddles a lot of stuff together, but it essentially says:

If addictive --> what’s true for a few habitual users ISN’T true for most habitual users

or in other words:

If addictive --> most habitual users will experience at least some difficulty when they try to quit

Now, to James’s question:

(C) I felt would be correct from the Expert's view, but he specifically says not everyone agrees, (and it is from the experts statements that we are supposed to infer). Ultimately if the Q-stem is asking what must be true based on the statements, (I know it says "properly infer" but I take that to mean must be true), then no statement of fact - of what is addictive should be correct, (it seems). After all, the only guaranteed thing in the stimulus is that people don't agree on what defines "addictive."

Great question. On inference questions, we have to take what’s given as true. So we must accept the expert’s statements. This is just a quirk of the LSAT: you have to take givens as facts. It doesn’t matter what others may think.

TJ, your question:

Despite the fact that it is the right answer, Answer C is not really airtight. "That is not true" refers to the first part of sentence, which after negation will read "Most habitual users CANNOT cease to use with little or no psychological or physiological difficulty" (most habitual users quit with more than little or no difficulty). is this the same as "withdraw from its habitual use causes most users EXTREME..."?

No, more than little or no difficulty does not have to be extreme difficulty. There can also be medium-level pain. Not that it's either little or extreme.

Thoughts?

Good point! However, let’s draw this out. The original statement says:

If addictive --> most habitual users who try to quit will suffer extreme difficulty

(C) says, to use your words:

If addictive --> most habitual users who try to quit will face more than a little difficulty.

Now, you’re right that these two statements are not identical. But our task is not to find something IDENTICAL to stimulus. Our task is to find something that MUST BE TRUE given the stimulus.

So if we take as true that quitting will cause most people to suffer "extreme difficulty," then quitting must also cause most people to suffer "more than a little difficulty."

Here’s an analogy:

Given: To go to law school, you must have completed four years of college.

Inference: To go to law school, you must have completed at least one year of college.

The inference and the given are not identical, but one year of college is a necessary stop on the way to four years of college. Therefore the inference "must be true" based on the given. Similarly, if quitting an addictive substance causes extreme pain, then it must also cause a little pain, since a little pain is a necessary stop on the way to extreme pain.

Does that make sense? Let me know!

--Rina

[kyuya]

This stimulus is a bit long, but if you learn to filter out what is important and what is not, it becomes a lot more manageable.

Following the first sentence of the stimulus, the next sentence begins with "some have suggested..." which typically suggests that the author does not in fact agree with the opinion being stated by. This is confirmed by the next sentence. The following sentence goes on to tell us what is wrong with the beliefs of the "some people" mentioned in the former part of the stimulus, suggesting that the authors opinion is about to be revealed.

The author suggests that a substance is addictive ONLY IF..

We know that introduces the necessary condition. So we can draw out the statement like this:

addictive --> withdrawal from its habitual use causes most users extreme psychological and physiological difficulty. This correct answer choice is contingent on us understanding this statement.

Lets get into the answer choices.

(A) This is a mistaken reversal. If we glance back to the condition statement, we will see that it is suggesting that the necessary condition leads to the sufficient, which is not something we can infer. Common wrong answer.

(B) We don't know if fewer substances would be deemed addictive or not, we are just not given this information. We don't know how many drugs are considered addictive according to what criteria.

(C) Here is the right answer.

We know that if something is addictive, it causes the user a lot of grief if he tries to quit. This is what is being said here, in a convoluted conditional statement. I'll try to parse out the language.

A substance that users could quit without much grief would NOT be addictive, according to our conditional above. The "only if" statement in the latter part of this answer choice suggests that although there are some people that can quit this substance without many issues, for MOST users that is not the case. So what does this mean? It means for MOST users its really hard to quit this drug. So it is addictive!

(D) We need to know about the person quitting and withdrawing in order to draw any inferences. This talks about the habitual USE of a drug, but not about what its like to quit said drug. Perhaps if you stay on a drug your whole life, you never face psychological or physiological issues.

(E) Again, we don't know this. Impossible is a really strong word, and the stimulus actually suggests the author has found a somewhat adequate measure to determine whether or not a substance should be considered addictive or not.

[roflcoptersoisoi]

(A) As Matt rightly pointed out there are two problems with this. First it switches around the necessary and sufficient condition of the conditional statement in the last sentence. Secondly this answer choice only has "one" user that withdrew experiencing psychological and physiological difficulties, whereas the stimulus has "most users", we don't know if this person in question is part of that group. A third issue is that we don't know if this person is even a habitual user.

(B) This is not at all inferable from the stimulus. We don't know the number of substances that are classified as addictive under the prevailing definition, nor do we know the number that would be classified as addictive if an adequate definition were employed.

(C) This is correct, but the language can be difficult to grasp. Essentially it is saying that a substance is addictive only if most of its habitual users cannot cease to use it without psychological or physiological difficulties.

(D) This could be true but need not be true given the information we're told in the stimulus. The uses the psychological and physiological effects WITHDRAWAL by most habitual users as a metric to determine whether substance is indeed addictive. This uses the effects of USING the drug as a metric for determining addictiveness, completely different. Eliminate.

(E) Nope.

[cgentry]

Question Type:
Must Be True
Stimulus Breakdown:
Everything in this argument stems from the last sentence: this sentence contains a convoluted conditional logic statement that can be used to prove one of the choices correct.

The below diagram can be used to illustrate the last sentence, particularly the last half of that sentence: “a substance is addictive only if its withdrawal...causes most users...difficulty.”

Addictive → most users have withdrawal difficulties
Answer Anticipation:
The correct answer will probably mimic the conditional statement at the end of the paragraph.
Correct answer:
C
Answer choice analysis:
(A) This is, at best, an incorrect reversal of the last sentence. Withdrawal difficulties → addictive. (This also does not acknowledge that the last sentence of the paragraph references most users having withdrawal problems.
(B) This choice would require numerical comparisons of how many substances are presently deemed addictive to how many terms would be deemed addictive under a different definition. But the expert never actually states how many terms are presently deemed addictive. In fact, the expert never states the present definition of addiction, just two proposed definitions of addiction.
(C) This has massive amounts of distracting elements, but at its core, this choice says “a substance...is addictive only if that is not true for most habitual users.” The tricky element is decoding what the word ‘that’ refers to in the quoted text. This ‘that’ actually refers to “users can cease to use with little or no difficulty.” Further translated, the choice, in essence, is “a substance is addictive only if most users cannot cease to use it with little difficulty. This a good paraphrase of the last sentence of the prompt paragraph.
(D) This choice fails because it does not hinge on difficulties due to withdrawal.
(E) The author thinks that addiction is definable: that is the last sentence.

Takeaway/Pattern:
In a Must Be True question in LR, if one is given absolutes, those will be the most useful statements for proving a choice correct.
#officialexplanation