Q18 - Journalist: Recent studies have

[ManhattanPrepLSAT1]

Question Type
Must be False

Stimulus
Smokers who have recently smoked a cigarette display significantly better short-term memory than nonsmokers, even if those nonsmokers have recently smoked a cigarette. Additionally, the majority of those smokers who display this superiority of short-term memory will do so for up to eight hours.

Answer Prephrase
The short-term memory of a nonsmoker is better than the short term memory of a smoker who has recently smoked a cigarette.

Correct Answer
(B) must be false. This comparison contradicts the comparison made in the stimulus.

Incorrect Answers
(A) could be true. Comparing a nonsmoker with a nonsmoker doesn't contradict the comparison in the stimulus.

(C) could be true. Comparing a nonsmoker with a regular smoker who hasn't recently smoked a cigarette doesn't contradict the comparison in the stimulus.

(D) could be true. Comparing a regular smoker who recently smoked a cigarette with another regular smoker who has recently smoked heavily doesn't contradict the stimulus.

(E) could be true. The statements in the stimulus do not specify whether the effect of smoking on short-term memory diminishes with time. Instead we are only told that a smoker who smoked a cigarette will display superior short-term memory compared to a nonsmoker for at least eight hours. This leaves open the possibility that the improved short-term memory diminishes over time.

#officialexplanation

[mrudula_2005]

(D) states "A regular smoker who, immediately after smoking a cigarette, exhibits short-terms memory skills no better than those typically exhibited by a nonsmoker..."

While the stimulus states "...a regular smoker who has just smoked a cigarette will typically display significantly better short-term memory skills than a nonsmoker..."

At first glance it would seem that this first clause in (D) directly contradicts the stimulus (and would thereby be the correct answer), but is it in fact consistent with the stimulus because the stimulus only says that "a regular smoker who has just smoked a cigarette will typically display significantly better short-term memory skills than a nonsmoker..." - so I guess the regular smoker in (D) is one of the minority?

Just looking for quick confirmation...

thanks!

[aileenann]

Yup you are absolutely right. That *typically* is doing lots of the work here. This particular smoker is in the minority.

[mdiaz.rod]

I had many issues with this question. At first glance, it seemed like none of the answer choices could be true. How to narrow it down to one answer choice?

After viewing some comments and studying the question for quite some time, I concluded that my initial problem was that I had been seeing this as a must be true question rather than a "˜could be true’ question (I could be wrong but I don’t recall encountering a could be true question in the logical reasoning section). Taking this into account, the answer choices make much more sense:

(A) Initially I had looked at this answer choice and thought to myself : "we don’t really know whether the nonsmoker who just smoked a cigarette will display short term memory skills that are usually substantially worse than the nonsmoker who has not recently smoked a cigarette. The stimulus does not compare the short term memory skills of the two types of nonsmokers. Because I was initially reading this as a MBT question, I initially thought to myself, this cannot be true! But now that I am reading it as a could be true question, I am realizing that it could be true or it could not be true. Because there is the possibility that it could be true, I can discard the answer.

(B) Could never be true. At most, the short term memory skills exhibited by a nonsmoker who has just smoked a cigarette are SOMETIMES superior to those exhibited by a regular smoker who has just smoked a cigarette. We can keep this as a strong contender.

(C) The stimulus says that the smoker who has recently smoked a cigarette will typically display better short term memory skills for at least 8 hours after having smoked. This means that anytime after 8 hours, these "˜better short term memory skills’ may have gone away, or they may still remain. We really don’t know. Therefore a nonsmoker who just smoked a cigarette could quite possibly display short term memory skills that are typically superior to those exhibited by a regular smoker who has not smoked for more than 8 hours.

(D) I definitely agree with the previous posting that it is quite possible that that regular smoker immediately after smoking a cigarette, can exhibit short term memory skills no better than those typically exhibited by the nonsmoker. This accounts for the minority and therefore could be true. Regarding the last part of the answer choice: why would the regular smoker be more likely to experience an improvement is short term memory skills as the hours go by following a period of heavy smoking? Nothing is mentioned in the stimulus about the short term memory skills improving as the hours go by and nothing is mentioned about heavy smoking. For all we know, heavy smoking could actually have a counter-effect on short term memory skills. We only know what happens after the regular smoker smokes 1 cigarette. Once again, because this is a could be true question, this ambiguity that arises in the latter part of the answer choice means that it could possibly occur, or it may not. Because it possibly could occur, we can eliminate this answer choice as well.

(E) We don’t really know whether the short term memory skills of a regular smoker who last smoked a cigarette 5 hours ago are typically superior to those exhibited by a regular smoker who has just smoked a cigarette. It could be true just like it could not be true. Therefore, it can be eliminated.

Is my reasoning accurate on this question? Feedback would be much appreciated.

[mshinners]

What does the Question Stem tell us?
Four of these answers could be true; the correct answer must be false. This means that it will contradict information given in the stimulus.

Break down the Stimulus:
"There are a lot of comparisons to keep track of here. We're talking memory, and we know that a smoker who smoked has better short-term memory than a non-smoker, whether that non-smoker has or has not smoked.

So we can say smoker who smoked > non-smoker.

We also get that most of these smokers will retain the better short-term memory for 8+ hours."

Any prephrase?
Since we're trying to find an answer that contradicts something we've been told, we should look for an answer that gives a non-smoker better memory than a smoker who has just smoked.

Answer choice analysis:
A) We never compare nonsmokers from different categories, so it's possible this is true.

B) This answer directly contradicts the comparison we found in the study by giving a non-smoker better memory than a smoker. This looks good for our answer.

C) The studies were done on smokers who just smoked, not on those who haven't smoked. Since we don't have the information to make a judgment, this could be true. It's also trying to pull in a detail from the last sentence, which isn't relevant to this comparison.

D) Our argument doesn't distinguish between heavy and light smoking. It also deals with the typical smoker (who does demonstrate good memory), and not those who don't display superior memory. Since we don't have the relevant information to make a determination, this answer could be true.

E) Our comparison is just made to non-smokers, so it's possible that the memory boost grows over time. We don't know, so it could be true.