A recent study found that snoring, though not common in either group

Question

A recent study found that snoring, though not common in either group, is more common among smokers than among nonsmokers. On the basis of this evidence, the author hypothesized that smoking by itself can induce snoring.

Which one of the following, if true, casts the most doubt on the author’s hypothesis?

(A) Stress induces both snoring and smoking in certain individuals.

(B) Obesity induces many individuals to smoke.

(C) Most snorers do not smoke.

(D) Most smokers do not snore.

(E) Both smoking and snoring cause throat problems.

septwibowo · Answer

IMO C, this is cause and effect passage. To cast the most doubt, we should provide another possible cause.

C says that most snorers do not smoke, means that smoking is not the cause of snoring.

Waiting for OE.

vmelgargalan · Answer

I would say A... if stress causing snoring and smoking, then people smoking and snoring is caused by stress and not by each other

nightblade354 · Answer

A recent study found that snoring, though not common in either group, is more common among smokers than among nonsmokers. On the basis of this evidence, the author hypothesized that smoking  by itself  can induce snoring.

-- Because of the 'by itself', we need to find an alternate cause. A states an alternate cause. C/D are the same answer, so they are incorrect.

Which one of the following, if true, casts the most doubt on the author’s hypothesis?

(A) Stress induces both snoring and smoking in certain individuals.
(B) Obesity induces many individuals to smoke.
(C) Most snorers do not smoke.
(D) Most smokers do not snore.
(E) Both smoking and snoring cause throat problems.

stne · Answer

Again its between A and D
Author says smoking can induce snoring . So most smokers should be snoring if not all. 
If we received evidence that such was not the case then it would certainly weaken the argument.

D directly opposes the author , it says most smokers do not snore, then smoking cannot possibly induce smoking,in this the Author is directly contradicted .
A on the other hand gives an alternate reason for both and is not as strong as D.

Please provide OE how D is wrong.

nightblade354 · Answer

Hi  stne ,

Let's analyze the question:

Here is the fist line of the question: "A recent study found that  snoring, though not common in either group, is more common among smokers than among nonsmokers " -- D does not weaken this. D says that most people most smokers do not snore. But how does it compare non-smokers and snoring? It doesn't. This doesn't weaken our conclusion, it just gives a relative figure to it. Further, the argument's conclusion is that snoring can be induced by smoking ALONE. How does this statement weaken that point? It doesn't, once more. A gives an alternate cause, as you pointed out, so it directly refutes the conclusion.

I think you became confused with the premise and the conclusion.

Does this help?

GMATNinjaTwo · Answer

Thanks  nightblade354  for the explanation!

Remember that you can always use the  request verbal experts' reply  button to post additional questions.

stne · Answer

Thanks for your explanation

gmatexam439 · Answer

A recent study found that snoring, though not common in either group, is more common among smokers than among nonsmokers. On the basis of this evidence, the author hypothesized that smoking by itself can induce snoring.

Which one of the following, if true, casts the most doubt on the author’s hypothesis?

(A) Stress induces both snoring and smoking in certain individuals. - Correct. From the premise we know that "most" smokers/non-smokers don't snore. So among the remaining few people stress induces both smoking and snoring habit. 
(B) Obesity induces many individuals to smoke. - Out of scope. The argument is about snore and not smoke. 
(C) Most snorers do not smoke. - We already know this from the premise. This is just restatement of the aforesaid fact. 
(D) Most smokers do not snore. - We already know this from the premise. This is just restatement of the aforesaid fact. 
(E) Both smoking and snoring cause throat problems. - Out of scope. The argument is about snore and not smoke.

Novice90 · Answer

Hi,

I have gone through the explanations in the thread below, but still fail to understand the logic:

Option A: "Stress induces both snoring and smoking in certain individuals". Though this option provides a new source that induces snoring apart from smoking, but it does not say anything about people without stress but who smoke. What about these people do they snore or not?

Option D: "Most smokers do not sore". This directly deals with the conclusion. It presents a fact that is exactly opposite of the conclusion. Most smokers do not snore and hence smoking has not induced snoring in many people

Hence, shouldn't the answer be option D?

Thanks!

GMATNinja · Answer

Yes, there are still smokers whose snoring cannot be blamed on stress, and without further information, we cannot say whether choice (A) actually  disproves  the author's hypothesis. However, it certainly  weakens  the author's reasoning. The author reasons that since snoring is more common among smokers, smoking  by itself  must be causing some people to snore. Choice (A) tells us that at least some of the smokers who snore are snoring because of stress not because they smoke. Perhaps if stress were not a factor, smokers and nonsmokers would be equally likely to snore. But because stress induces smoking AND snoring, the data, on which the hypothesis is based, is misleading.

As for choice (D), the conclusion is that smoking  by itself  can induce snoring. This does not say that smoking always or even usually induces snoring. Rather, it says that smoking, by itself,  can  induce snoring. The author's hypothesis does not require that most smokers snore. In fact, the passage even states that snoring is not common among smokers. This fact does not impact the author's reasoning, so choice (D) can be eliminated. As long as  some  smokers snore, the author's hypothesis is feasible.

Skywalker18 · Answer

PREMISES
Snoring not common among smokers or non-smokers
Snoring more common among smokers.
CONCLUSION
Smoking by itself can induce snoring.
This is a classic causation/correlation mistake. We know A is correlated with B, and the author assumes A therefore must cause B. Classic rebuttals to this are:
1) reverse causation: B might cause A
2) third party: C might cause both A and B
3) coincidence!

(A) nails the target by introducing a third party, stress, that could be responsible for causing both snoring and smoking, which would handily explain the correlation.

Not the Problem
(B) This doesn't explain the connection to snoring.
(C) The conclusion was only that smoking could induce snoring, not that it was the only possible way to induce snoring. If most snorers don't smoke, then their snoring is caused by something other than smoking, but that's okay - it doesn't damage the conclusion.
(D) We were already told this in the premise!
(E) Who cares what smoking and snoring cause, we want to know what causes THEM!

bhavik1995 · Answer

Option D is contradicting the fact by saying MOST (more than 50%) smokers do not snore. Smokers + Not snoring > Non Smokers + Not snoring
But author has stated the fact that snoring is more common in smokers. ie Smokers + Snoring > Non smoker + Snoring

Therefore D is wrong.

Whereas A is saying something else causes snoring and smoking.
Which is a type of weakening.
 
KUDOS  please!
Thanks.

auradediligodo · Answer

A recent study found that snoring, though not common in either group, is more common among smokers than among nonsmokers. On the basis of this evidence, the author hypothesized that smoking by itself can induce snoring.

Which one of the following, if true, casts the most doubt on the author’s hypothesis?

Weaken question

Pre-thinking

Falsification scenario:   What if snoring induces people to smoke on some level? What if another cause induces both snoring and smoking? In this case the argument would break.

Assumption  : There are no other causes that induce both snoring and smoking.

POE:

(A)   Stress induces both snoring and smoking in certain individuals.
 In line with our falsification scenario

(B) Obesity induces many individuals to smoke.
 irrelevant

(C) Most snorers do not smoke.
 irrelevant

(D) Most smokers do not snore.
 irrelevant

(E) Both smoking and snoring cause throat problems.
 irrelevant

Source: LSAT

unraveled · Answer

A recent study found that snoring, though not common in either group, is more common among smokers than among nonsmokers. On the basis of this evidence, the author hypothesized that smoking by itself can induce snoring.

Which one of the following, if true, casts the most doubt on the author’s hypothesis?

(A) Stress induces both snoring and smoking in certain individuals. - CORRECT. Another reason that might have caused snoring not smoking only.

(B) Obesity induces many individuals to smoke. - WRONG. What about snoring.

(C) Most snorers do not smoke. - WRONG. Causality is still questionable.

(D) Most smokers do not snore. - WRONG. Like C only.

(E) Both smoking and snoring cause throat problems. - WRONG. Irrelevant.

Answer A.

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A recent study found that snoring, though not common in either group

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