#18 - Medical researcher: A survey of more than 1 million

[Administrator]

Complete Question Explanation

Flaw in the Reasoning. The correct answer choice is (A).

A fairly straightforward causal argument based on a correlation, this question proved surprisingly challenging due to most of the answers using causal language in ways that proved confusing and distracting.

A medical researcher shares the somewhat surprising results of a far-reaching survey, which indicate that getting at least 8 hours of sleep per night correlates with being less healthy than those who sleep much less. He then concludes that sleeping less is actually good for us, leading to (causing) greater health. Because this is a causal argument, there are several ready-made prephrases at our fingertips: the author has failed to consider alternate causes, or the possibility that the supposed cause and effect are reversed (maybe illness causes us to sleep more?), or problems with the data (surveys are often the source of such problems - here, self-reporting might be inaccurate, for example.) Any of these would make a good answer choice.

Answer choice (A): This is the correct answer choice. Here we have a standard Alternate Cause answer, exactly what we should be looking for, and so it should at least be a contender as you move to examine the remaining answer choices. Students who decided not to read the remaining answer choices were, for once, rewarded for being so bold (but don't make that a habit!)

Answer choice (B): This answer is also causal, and might be a flaw IF the author had said something along the lines of less sleep being the SOLE cause of better health, or more sleep being the ONLY cause of the increased incidents of illness. Since the author did not make such a strong claim, but played it safer with a softer claim that less sleep probably helps bolster the body's defenses, this answer does not describe a flaw made by this particular author in this particular case.

Answer choice (C): A conditional answer choice is almost never going to be the correct answer to a causal flaw in the reasoning, and it is not correct in this case. We should select an answer that deals with causal reasoning. Also, take note that the medical researcher never indicated that any phenomenon was sufficient for (meaning absolutely guarantees the occurrence of) another phenomenon, but only that there is a general correlation between two phenomena.

Answer choice (D): This answer reverses what the author did in the stimulus. Our author did not claim that because one thing has some causal impact on another, the two must be correlated; he said that because two things are correlated, one of them probably has some causal impact on the other. A tricky shell game! The correct answer to a Flaw question must describe something that actually happened in the stimulus, and this answer does not pass that test.

Answer choice (E): Translating this answer into simpler English, it is saying "just because one thing doesn't cause a particular problem doesn't mean it causes no problems." As our author is not saying anything about sleep, or a lack of sleep, NOT causing a problem, this answer does not describe anything that occurred in the stimulus, and is therefore a loser.

[amydg]

This question wasn't a source of confusion, but the answer choices were very difficult to discern. I felt A, B, and D were adequate answers to provide for the vulnerability in the argument. Could you explain why A is most correct and B&D are incorrect? Thank you.

[Nikki Siclunov]

Amy,


Please provide a detailed breakdown of how you understood the argument. At the very least, we expect to see evidence that you were able to:

• Deconstruct the stimulus into premises/conclusion.
• Understand whether the conclusion logically follows from the premises, and if not - why not?
• Correctly identify the type of question in the stem.
• Prephrase an answer to that question. (Don't be afraid if your prephrase was off - we still need to see what it was).
• Defend your choice of (incorrect) answer choice.

The more you tell us about your method of approach, the better we can help you figure it out. And by the way, there is no such thing as a "more correct" answer choice They are either correct or incorrect. It's a binary system, for better or worse.

Thanks!

[actionjackson]

For this question I incorrectly chose answer choice E as my response. I broke down the argument as:
Premise: Survey of more than 1 million adults found a greater frequency of illness among people who regularly slept at least 8 hours a night than among people who slept significantly less.
Conclusion: This (survey) shows that mild sleep deprivation in not unhealthy, and probably bolsters the body's defenses against illness.

Seeing as how this is a flaw type question, the reasoning of the argument is questionable at best. I initially thought flawed survey, introduction of a new concept (sleep deprivation) and then I believed the author provided a positive correlation in his/her premise, but I didn't see the conclusion as a causal one. Seeing as how A, B, and to a lesser extent D, all deal with causality and seeing as how I was running out of time for the section, I thought that this can't be a causal reasoning error. Whereas E seems to be describing the flaw: error in the use of evidence. Specifically that there could be other negative consequences that mild sleep deprivation could bring about such as: poor concentration, hallucinations, etc. Would these just be weakeners? What I believe threw me off from thinking that this was a causal reasoning stimulus was the author's use of the term 'probably'. How does A accurately represent the reasoning flaw of this argument and B does not? Does B only weaken the argument?

As always, thank you Powerscore.

[Francis O'Rourke]

Hi Jackson,

Thanks for explaining your reasoning there! There are two points that I want you to consider. One is that an incorrect answer choice for an Identify the Flaw question can be true, but doesn't actually describe a flaw in the argument.

You are correct that sleep deprivation could have other consequences. But your examples don't really add anything to the information we already had in the premises. We already know about the rates of illness, so that would seem to cover hallucinations and inability to focus.

The second one is debatable, so let's agree for now that lack of focus is not an illness. If lack of focus is not an illness, can we say that if you lack focus, then you are unhealthy? Let me explain why this is important.

An "other negative consequence" described in Choice (E) is either illness or not an illnesses. If it is an illness, then the stimulus already described the rates between the two groups. If it is not an illness, then how can it affect the conclusion, which only makes claims about health and illness? It can't, so the speaker never needed to address these other effects.

This stimulus might be using "health" in a way that is more restrictive than your everyday usage. While you might think of health as including "wellness," this medical researcher seems to restrict "health" to a spectrum from ill to healthy or unhealthy to illness free.


The second important point is missing the causal connection in the conclusion. The language is a bit odd here, so I can understand not catching it at first. There are a lot of words that I can use to indicate that A causes B. For example:

• A leads to B
• A produces B
• A made B
• A causes B
• A increases B
• A bolsters B

All of those phrases indicate that A has acts on B in some way or A makes B occur or change. Bolster is not a typical way of expressing this idea, but it is synonymous with "leads to an increase in." Any time I question whether a statement is indicating a causal relationship, but uses atypical word choice like "bolster" I ask myself if I can rephrase it with some more common causal indicator, such as "causes" or "leads to." If it can and no the meaning is unaltered, then the relationship is causal.

As for the term probably: it is completely acceptable to qualify a causal relationship with this term. For example, consider the statement

• high unemployment probably causes a slowing of inflation

An economist might want to make such a statement to show that they believe that this causal relationship likely exists, but it has not been proven beyond a doubt.

[bk1111]

I understand the fallacy and the answer choice. I am just seeking further clarification about what answer choice C really means. I unpacked it generally as being a conditional fallacy, but I am confused about what it is trying to say.

"concludes, from the claim that a certain phenomenon occurs and the claim that a certain condition is sufficient for that phenomenon to occur, that the condition also exists"

Additionally, what would be an instance of answer choice E being correct? Arguments generally pertain to specific claims, so when would "other consequences" be relevant to consider, or lack thereof be a flaw? ...I hope what I am saying makes sense.

Thank you

[Charlie Melman]

Hi bk,

Answer choice (C) means that the argument claimed that "x" is a thing, and claimed that "y" causes x; then concludes that y is a thing. This is a fallacy, but not what we're looking for. This is a fallacy because the author can't propose that y would cause x and then conclude that y exists. Maybe y is a plausible explanation, but not an actual thing.

Answer choice (E) would be right if the argument said, "this thing, "x," doesn't cause disease, but that doesn't mean that x doesn't cause other bad things, like drowsiness."

Hope this helps.

[OPD]

Hi bk,

Answer choice (C) means that the argument claimed that "x" is a thing, and claimed that "y" causes x; then concludes that y is a thing. This is a fallacy, but not what we're looking for. This is a fallacy because the author can't propose that y would cause x and then conclude that y exists. Maybe y is a plausible explanation, but not an actual thing.

Answer choice (E) would be right if the argument said, "this thing, "x," doesn't cause disease, but that doesn't mean that x doesn't cause other bad things, like drowsiness."

Hope this helps.

Hi Charlie,

If the conclusion were to be structured "Mild sleep deprivation doesn't cause disease, but that doesn't mean that mild sleep deprivation doesn't cause other bad things, like drowsiness", would that not entirely address E? This might be a case of misinterpretation on my end, but I'd like to clarify nonetheless. Thanks.

[Luke Haqq]

Hi OPD,

You write,

If the conclusion were to be structured "Mild sleep deprivation doesn't cause disease, but that doesn't mean that mild sleep deprivation doesn't cause other bad things, like drowsiness", would that not entirely address E?

Yes, if the conclusion were to have been phrased that way, it would address (E). Indeed, I think that's why Charlie was offering that phrasing in his post--as a possible way that the conclusion could have been phrased if (E) were to have been the right answer. However, as it's worded originally, a criticism of the argument is that it sees an association between two phenomena (shorter time sleeping and frequency of illness), and it assumes that the former causes the latter. However, it could be possible that another cause (such as being physically fit) actually accounts for both of those phenomena--i.e., physical fitness might cause people to need lower-than-average amounts of sleep and also cause them to become ill less frequently. And that criticism of the argument is reflected in answer (A).

[mjb514]

Can you please explain why B is wrong. I was under the impression that the given factor was the "people who regularly slept at least 8 hours," and the phenomenon was the "greater frequency of illness" they experienced. Thus, the fact that sleeping for at least 8 hours was not he only factor affecting the illness, seems like it would weaken the argument.