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

[Francis O'Rourke]

Answer choice (B) essentially states that the speaker concluded that sleep deprivation alone causes increased health, but the speaker forgot that sleep deprivation may only be one of several or some factors that contribute to good health.

This is not an accurate description of the speaker's argument, so it fails the Fact Test and is incorrect. This answer is an example of a common wrong answer for Flaw in the Reasoning questions: a wrong answer may describe a flaw that was not actually present in the given argument.

[emekj]

Hi!
I am struggling to figure out why E is incorrect. Just because there is a lower rate of illness among sleep deprived people does not make them less healthy. They could be more likely to be obesity, for example, which is unhealthy, but is no, in itself, an illness. There are lots of things that aren't "illnesses" but are unhealthy so i'm not sure how only determining that sleep deprived people are less prone to illness makes it obvious that sleep deprivation is not unhealthy.
I understand why A is correct and had trouble choosing between A and E on this question. If you could explain what I am missing about answer E that would be great!

[Jonathan Evans]

Hi, EmekJ,

Good question! Let's parse through answer choice (E) to see how it matches up with the stimulus:

• "specific negative consequence" = this refers to illness
  "a given phenomenon" = this refers to sleep deprevation
  "that phenomenon" = sleep deprivation
  "other negative consequences" = other bad stuff

In other words, (E) can be understood as:

• "The author fails to consider that even if illness is not associated with sleep deprivation, sleep deprivation may cause other bad stuff."

Is this what's going on here? Is the problem with the argument that the author has failed to think about other bad stuff sleep deprivation might cause? Not exactly. The argument restricts itself to discussing the cause-effect relationship between sleep deprivation and illness and is not concerned with other possible consequences of sleep deprivation. The concept of "frequency of illnesses" is a close enough analog to being "healthy" that this is not a significant enough shell game to cover the umbrella of "bad stuff" in our sentence above. In addition, the conclusion refers again directly to illnesses, so we're talking about the same thing in the premises and the conclusion.

Does this make sense?

[jsilve17]

Hi,
I originally chose E because of the (what i thought was mistaken) implication that lack of illness automatically meant not unhealthy. I figured there could be something like weight gain resulting from lack of sleep, which is not considered an illness, but is still an unhealthy behavior. I see how A could be write, but not 100% sure why E is wrong. Furthermore, more generally, would you consider A to be stronger since it would address both parts of the conclusion (not unhealthy AND bolsters the defenses) whereas E only addresses one aspect of the conclusion?

[George George]

Excellent Qs, jsilve17 - I like how much you pay attention to detail here. Let me address these 2 concerns.

First, (1) Why is (E) wrong?

Short answer: (E) is not the overlooked possibility. Whenever a flaw answer uses the phrase "fails to consider" or "overlooks the possibility," the answer can only be correct if it describes a viable alternative to the assumption.

Long answer: Here, the assumption is that sleep deprivation does not cause illness/health problems. (This is a Cause and Effect argument.) So, the only overlooked possibility would be that sleep deprivation somehow does cause illness. Any answer which points out that maybe sleep deprivation might be causing people to get sick would be an overlooked possibility. As stated above, "The argument restricts itself to discussing the cause-effect relationship between sleep deprivation and illness and is not concerned with other possible consequences of sleep deprivation." In other words, this is a Cause and Effect argument; it's not an argument claiming that sleep deprivation is has "zero negative consequences." The argument is limited to establishing that sleep deprivation is not unhealthy, but it doesn't care if sleep deprivation affects your work performance!

Second, (2) Is (A) better in part because it addresses "both" aspects of the conclusion in a way that (E) omits?

I like what you're thinking about here, but I don't think that (A) addresses both "not unhealthy" and "bolsters the body's defenses against illness." I think (A)'s reference to "both phenomena" refers to "sleep deprivation" (the cause) and not being "unhealthy" (the effect). So I don't think that's why (A) is correct, in general, but it's not a bad thing to look for those distinctions!

[lanereuden]

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.

Answer choice C is just fancy way of saying: hey, we saw the necessary condition occurring and now we are assuming that the sufficient condition is also present, i.e. mistaken reversal?

[lanereuden]

Is D even a flaw? I mean if you have cause, then you automatically have correlation. I don’t get what D means, because in my eyes it surely isn’t describing a flaw whatsoever

[ashnicng]

Could someone clarify what D means and is it a flaw? If two variables are in a causal relationship, doesn't it mean that there would also be a observable correlation between the two?

Also, is it logically sound for me to eliminate B because it assumes a sound causal argument, when the author wrongly assumed causation from correlation? I eliminated C because there is no conditional reasoning used.
Thanks!

[Adam Tyson]

Hey lanereuden and ashnicng, answer D is interesting, isn't it? I think it does describe a flaw, although a pretty reasonable one on its face. Is it wrong to presume that if one thing causes another, we should see some correlation between them? It seems like we should, but what if the causal factor is but one of several, and there is enough variation that we can't see any clear correlation despite there being some causal relationship? I think it's theoretically possible for a causal relationship to exist and yet not be observed as a correlation due to other factors masking that relationship.

Let's say it's a flaw. It's just not the correct flaw in this case, because the author doesn't presume that we could observe a correlation. He says we already DO see a correlation, and then presumes that there is something causal going on. D looks to be backwards compared to the flaw in the stimulus.

And lanereuden, you're right about answer C - it's a Mistaken Reversal answer, and since this argument is not conditional, that makes it a loser. Well done!

[lauriesnyder]

Hi,

I want to make sure I understand the key difference between A and B correctly.

A says "the possibility that an observed" and B says "even if a given factor causally contributes to the occurrence." So where B goes wrong is saying that the stimulus states that sleep deprivation does increase health, whereas A keeps in line with what is actually said in the stimulus - that it's an observed correlation. Right?

Thanks!