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#23419
Complete Question Explanation

Parallel Flaw—CE. The correct answer choice is (C)

The flawed pattern of reasoning in this stimulus is as follows:

Obesity associated with high fat diets is caused by lacking nutrition, rather than excess calories. Thus these people do not consume too many calories.

What is the problem here? Just because obesity is not caused by excessive calories per se, that doesn't mean that these obese people shouldn't worry about the other problems associated with excessive caloric intake.

The correct answer choice will probably point out a causal relationship that is lacking, and conclude that there is no cause for concern.

Answer choice (A): The causal link drawn in this conclusion is much different from the stimulus' conclusion that a detriment is no cause for concern.

Answer choice (B): The conclusion here is also very different from that found in the stimulus: "thus most beer drinkers are fans" is very different from "thus the obese do not need to reduce caloric intake." Since this answer choice fails to Double the Conclusion, this one is incorrect.

Answer choice (C): This is the correct answer choice. The detrimental disorientation is not attributable to sleep deprivation but to irregular schedules. Thus the referenced pilots do not need to get more sleep?

This flawed reasoning nicely parallels the argumentation presented by the author of the stimulus, so this one's a winner.

Answer choice (D): This answer choice presents a different kind of logical flaw—a conclusion drawn with a lack of any evidence:
  • Premise: ..... Stock market crashes are not caused by economic downturns

    Conclusion: ..... Thus economic downturns cannot accurately be predicted.
As we can see from a quick glance at the argument above, we cannot justifiably based that conclusion on that premise. But this flaw is different from that in the stimulus (the mistaken notion that if a factor is not detrimental in one limited context, it must not be detrimental in any other).

Answer choice (E): The causal argument here is flawed—a conclusion about programmers is drawn based on the cause of the large numbers of graduates. But like the other incorrect answer choices above, this one does not parallel the specific type of flaw found in the stimulus, so this answer choice is incorrect.
 Blueballoon5%
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#27608
I am confused with the answer key explanation.

The explanation states that, “What is the problem here? Just because obesity is not caused by excessive calories per se, that doesn't mean that these obese people shouldn't worry about the other problems associated with excessive caloric intake.”

But the stimulus never mentioned other problems associated with excessive caloric intake. It only stated that, “people on these high-fat diets do not consume too many calories.” How can the flaw be something that the stimulus never stated or suggested? The stimulus never said that there were no other problems associated with excessive caloric intake.

I hope you can help! Thanks!!
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 Jonathan Evans
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#27638
Hi, Blue,

Good question. In my LSAT lessons 4-8 book, there are no answer explanations given for this particular problem set, so unfortunately I cannot comment on the specifics of this answer explanation. However, I am happy to talk about this problem and what you should do to get it right.

First, whenever you need to parallel the flaw, you need to focus on the flaw as the key component you need to match. Second, you need to identify the components involved. The key to success on these problems is an ability to describe what is wrong (parallel the validity) and the core components (parallel the abstract structure). Once you have this prephrasing complete, you match your prephrasing to the answers. It becomes very mechanical.

On this problem, we know:

Premises: Some obesity resulting from high fat diets not caused by excessive calories. Instead caused by lack of certain nutrients.

Conclusion: People on these diets don't consume too many calories.

What's going on here? Okay, just because we know it wasn't the calories that caused the obesity doesn't mean the diets couldn't also involve excessive calories. Causal flaw. That's the first step in prephrasing this.

Now let's describe abstractly what's going on here. So, there's a phenomenon. It's caused by one thing (1) and not by some other thing (2). Conclusion is: So thing (2) must not happen.

Now Process of Elimination:

(A) right off the bat, elements don't match up. No two things in premises.

(B) Premise okay. Conclusion way off base. No match

(C) phenomenon (disorientation) caused by one thing (sunlight disruption) and not by other thing (sleep deprivation). Conclusion: so no sleep deprivation. We have a match.

(D) Premise great. Conclusion way off.

(E) Again, premise fine. Conclusion way off. "Most"

It's a matching process. The better your prephrasing, the more precisely you break these down into their key parts, the faster and better you will get at these problems. Without seeing the rest of the explanation you are referring to, I don't really perceive anything wrong there. Basically, the explanation is helping you understand that just because one thing (too many calories) doesn't cause the phenomenon (obesity) doesn't mean we can rule out excessive caloric intake. This explanation, from what I can ascertain, is simply helping to illustrate the overall structure of this argument and what's wrong with it. I hope this explanation helps.

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