Q27

[SecondWind180]

I felt like the passage was more or less explaining how high and low serotonin levels affect carb cravings.



The reason I didn't like E is because I didn't see a "phenomenon" described. Instinct tells me it's because of lines 1-5, but if you could elaborate and further prove it over choice D I'd appreciated it.

I chose choice D because I had the perspective of: The author is giving all this evidence and support so that he can say, in that last sentence, here's all the stuff we've learned now we need to study other things about serotonin.

Reading it a couple more times, I can see the the last sentence in the passage, where choice D is derived, isn't nearly as forceful as answer choice D reads. If you could possibly elaborate a little more on why D is wrong I'd appreciate it.

Thanks in advance!

[christine.defenbaugh]

Great question SecondWind180!

As a general piece of advice, I'd say that it pays not to hairsplit on words like 'phenomenon' on the LSAT. The 'phenomenon' here is simply the situation the entire passage is set up to discuss: that the brain knows when we should eat carbs. That is a phenomenon (a fact or situation that is observed to exist or happen, esp. one whose cause or explanation is in question). It might not be the word you would choose to describe the situation, but it's perfectly appropriate. Answer choices are generally not incorrect for using a word like 'phenomenon' unless there is absolutely nothing that could possibly apply in any reasonable interpretation of the passage.

For primary purpose questions, we've got to think about the passage as a whole. Let's run through a breakdown of the passage map:

1st: Introduce phenomenon: the brain knows when to eat carbs. WEIRD! We don't know much, but we know seratonin is involved.
2nd: The amount of carbs you eat affects the blood/brain seratonin levels
3rd: The amount of brain seratonin affects the amount of carbs you choose to eat.
4th: Drugs that promote/inhibit seratonin decrease/increase the amount of carbs people crave. Also, people who crave carbs feel good after eating them, people who don't crave carbs feel sleepy after eating them - so seratonin does other stuff too.

The first paragraph sets up the weird thing the author wants to talk about - the brain knows when it wants carbs! Everything else in the entire passage serves that primary purpose. We don't know much, but we know <insert all that stuff about seratonin>. This overall structure matches up with (E).

So why not (D)? The only possible evidence for (D) is the final sentence, and we would have to believe that the entire passage is building up to that final sentence. In some ways, this is like a logical reasoning question: where the author's conclusion? Does the author discuss all that crazy stuff about seratonin and carbs solely for the purpose of suggesting at the end that there's more stuff out there about seratonin that might be interesting to investigate? No! All that crazy stuff about seratonin is helping explain the weird thing about the brain knowing when it wants carbs.

The author's purpose came at the beginning, with the following paragraphs supporting it. (D) would suggest that the author's true purpose is hidden until the final sentence, and every paragraph supports it directly - and that's not true.

And you're completely right to notice that the final sentence is not really as strong as (D). It merely says that this one observation suggests there may be other weird stuff about seratonin. It does not actually say we must or should investigate that stuff.

The remaining answer choices all introduce a conflict that isn't present in the passage:
(A) No point of view is being defended against attack
(B) No misconception is raised that must be corrected
(C) While a lot of evidence is discussed, none of it appears to be conflicting.

I hope this helps clear this question up a bit!

[SecondWind180]

So why not (D)? The only possible evidence for (D) is the final sentence, and we would have to believe that the entire passage is building up to that final sentence. In some ways, this is like a logical reasoning question: where the author's conclusion? Does the author discuss all that crazy stuff about seratonin and carbs solely for the purpose of suggesting at the end that there's more stuff out there about seratonin that might be interesting to investigate? No! All that crazy stuff about seratonin is helping explain the weird thing about the brain knowing when it wants carbs.

The author's purpose came at the beginning, with the following paragraphs supporting it. (D) would suggest that the author's true purpose is hidden until the final sentence, and every paragraph supports it directly - and that's not true.

And you're completely right to notice that the final sentence is not really as strong as (D). It merely says that this one observation suggests there may be other weird stuff about seratonin. It does not actually say we must or should investigate that stuff.

This is the assessment of D I was looking for. Thank you!

[veengeecomm]

Here's my issue with D.

At the top of the first paragraph the author states:

"The answer to this question is not known, but one element in the explanation seems to be the neurotransmitter serotonin..."

And at the end of the passage:

"These findings suggest seretonin has other effects that may be useful indicators of seretonin levels in human beings"


Taken together these two statements seem to indicate to me why a suggestion for further study could not be ruled out as an AC.

I understand why E is correct. I am at a loss as to how to eliminate D though? Please someone show me how to discount these two statements making E correct.

Thanks!

V