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

[Adam Tyson]

Right, Laurie! It's not about taking evidence of a causal relationship and assuming it is the only cause (answer B), but taking a correlation and assuming it is causal in a specific way (instead of perhaps an alternate or reversed causal relationship) (answer A). Nicely done!

[dandelionsroar]

Hi, I understand why A works but I still don't understand why D couldn't. While I can see now how it reverses the premise and conclusion in the stimulus, in this instance wouldn't that be ok? While the researcher doesn't say it, wouldn't answer D be an implicit assumption to his conclusion?

My understanding is that he takes for granted a causation between two phenomena if there is a correlation between the two. Or is it a mistaken reversal? Maybe the wording is confusing me.

Thanks for any help!

[Jeremy Press]

Hi dandelionsroar,

You're absolutely right that the author's assumption is this: "If there's a correlation between two phenomena, then there is a causal relationship between those phenomena," which, incidentally, is the classic "mistaking correlation for causation" flaw! We diagram it as such: Correlation Causation

And you're also correct that the way answer choice D is written is a mistaken reversal of that assumption: "If there's causation, then there's correlation." Causation Correlation (the mistaken reversal!).

Since an author is never required to assume the mistaken reversal of a conditional relationship that's part of his or her argument, answer choice D is inaccurate (the author is not necessarily taking that mistaken reversal relationship "for granted").

I hope this helps!

Jeremy

[caitlin3296]

I'm still confused as to why E is not the correct answer. I think I may be misunderstanding either the argument or the task of the question.

I thought the author's argument was "mild sleep deprivation is not unhealthy and, in fact, probably bolsters the body's defenses against illness." I specifically paid attention to the author saying that "mild sleep deprivation is not unhealthy." With this in mind, E looked like the correct answer because the author assumes that sleep deprivation is not unhealthy based on the findings of the study and fails to consider that the phenomenon may have other negative consequences and be unhealthy after all.

Can someone show me where I went wrong?

Thank you!

[Frank Peter]

HI Caitlin,

I would say that if a counter-argument here focused on "other negative consequences", that wouldn't be a counter-argument that seeks to prove that sleep deprivation actually is unhealthy. "Health" as a concept shows up pretty frequently on the LSAT, and by its nature it is a pretty broad concept. So if we are talking about "other negative consequences" it would have to be something outside of health - maybe perhaps there are financial consequences or interpersonal consequences. But since we are trying to show how the argument is most vulnerable to criticism, we should focus on attacking the argument on its own terms. (A) points to the biggest problem with this argument: the possibility that maybe it's not that sleeping more causes illness, but that illness is causing some to sleep longer.

[jmulder615]

I am happy to be proven wrong, but this seems like a question that has two possible correct answers. I obviously do understand why A is correct: this is a cut-and-dry causal flaw. However, I don't think E is necessarily incorrect. At the end of the day, this argument deals with what is "unhealthy." It would be a mistake to deduce that health is a binary question of illness vs. non-illness. For example, there could be a myriad of physical or mental consequences that could be unhealthy from sleep deprivation that would not constitute illness. This is, objectively, a part-to-whole flaw, in which the author takes one component of health at large, notices that it is not associated with something, and deduces that health generally has been secured. Of course, within that conclusion itself is a causal flaw, but the presence of a causal flaw doesn't eliminate the possibility that there are multiple flaws present. I have visited explanations for three different LSAT platforms, and none of them have given a super good explanation of why this is wrong. All explanations have limited health to the binary scale I discussed which just doesn't seem super appropriate or indicative of what health really means

[Jonathan Evans]

Hi, jmulder!

Good analysis!

You're right that health and illness are not necessarily a binary spectrum. However, answer choice (E) is not correct for several reasons.

The conclusion has two claims: (1) mild sleep deprivation is not unhealthy, i.e. mild sleep deprivation is either health neutral or healthy, and (2) mild sleep deprivation probably protects against illness.

We do this on the basis of an observed correlation.

This is a straight correlation to causation fallacy, which makes answer choice (A) the answer that describes why the argument is most vulnerable to criticism.

However, beyond the objectively more accurate answer choice (A), let's take a closer look at answer choice (E). The first part of answer choice (E) again describes this correlation or lack thereof between illness and mild sleep deprivation. This is fine. The breakdown occurs when you try to connect the second part of answer choice (E) to the conclusion.

With respect to the first part of the conclusion ((1) mild sleep deprivation is not unhealthy, i.e. mild sleep deprivation is either health neutral or healthy), even if mild sleep deprivation had other negative consequences, we cannot assume that these negative consequences are health related. For instance, the other negative consequences could be that you doze off at your job all day. We introduce our own unwarranted assumptions to try to connect answer choice (E) to the conclusion.

With respect to the second part of the conclusion ((2) mild sleep deprivation probably protects against illness), the inadequacy of answer choice (E) becomes even more apparent. The claim in the conclusion is about a causal relationship between mild sleep deprivation and incidence of illness. The second part of answer choice (E) is in no way a "shell game;" we are talking about illness in the premises, and in the second part of answer choice (E) we are still making a conclusion about illness. Any other "negative consequences" are not germane and do not describe this fallacy.

At best answer choice (E) could only be relevant to describing a flaw in the first part of the conclusion, and even there we have to introduce our own assumptions to make it work.

Therefore, answer choice (A) is the best answer.

I hope this helps!

[LeBronSAT]

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?

How would you paraphrase the answer choice A based on what is stated in the passage? I read one staff members explanation on this thread, and they said that "... to both phenomena" refers to sleep deprivation and not being unhealthy; however, I would be remissed to say that I understand why another factor could contribute to both phenomena, because why would another factor contribute to the cause of a causal relationship? I understand why another factor could contribute to the effect, just not the cause.

[Adam Tyson]

When an author presents evidence of a correlation, and then concludes that the relationship is causal, there are certain standard flaws inherent in the argument, one of which is that there could be some other cause for the alleged effect, or for both of the observed phenomena in the correlation. Answer A isn't something you would assume to be true, but it is something that is a possible alternate explanation for the correlation that the author failed to consider, and that's why it describes one of the flaws in this argument.

There are other flaws here, too. For example, the author failed to consider that being ill might cause one to sleep more. The causal relationship could be reversed.

They also failed to consider potential problems with the study. Even though they looked at a million people, could it be that those people all lived in one geographic region, or were all around the same age as each other? They might be an unrepresentative sample of the general population. Or what if the questions were worded in such a way as to influence the answers, like "do you feel generally healthier when you sleep less than 8 hours a night?" That might indicate some bias in the questions, which undermines the conclusion.

Regarding answer A, perhaps certain lifestyle factors cause one to sleep less AND be healthier, like maybe getting up early to go to the gym? Maybe there is some genetic factor that makes people generally less healthy and also that causes them to sleep more? Maybe there is something in their diet that leads to both poor health and more sleep, like something that saps your energy and vitality?

Start by recognizing that there may not be any causal relationship at all, and that the author could be completely wrong about that. Then, thinking of some third thing that causes the alleged cause isn't so surprising, because it never was the cause in the first place! That was just a mistake made by the author.