Q20 - Galanin is a protein

[kimnamil14]

Can someone please explain why A and B are wrong answers?

Since the conclusion says that galanin causes rats to crave fatty foods and the question asks you to support that argument, I'm thinking that choices A and B eliminate alternate explanations for rats' preference for fatty foods, thereby strengthening the force of galanin as a cause for rats' behavior.

What I thought was, A eliminates the possibility that it could have been a simple craving for fatty foods that made rats choose fatty over lean foods, thereby giving more strength to the conclusion that it was galanin, and not a simple craving.

Similarly for B, I thought it eliminates the possibility that maybe it was the fat, not galanin, in the brains of the rats that induced rats to choose fatty foods.

Please point me to the right direction! Thank you in advance!

[aileenann]

Hi there,

You definitely identified the conclusion correctly, so good job doing that and also making sure you took the time to do that before jumping into the answer choices.

I think the most helpful is to go through all the answer choices keeping in mind that we want to strengthen the conclusion that rats with higher levels of G choose the fatty foods given the data included in the argument.

(A) is kind of weird. It may look like it strengthens, but it actually weakens. Remember, the conclusion is that galanin leads to a higher craving for fat (pay attention to the wording). But this answer choice is saying that lots of rats who craved fat didn't necessarily eat it for whatever reason. Well if that is the case, there is no reason to believe that the only rats who had cravings for fat were the rats who actually ate the fat. Therefore there is no reason to pay special attention to this group as far as cravings.

The reason this answer choice is so tricky is it's easy to forget to distinguish between craving the fat and eating the fat. But they are different!

(B) is kind of funny - just weird thinking about a fatty brain, though I guess there should be lots of fat from all those myelin sheaths on the nerve cells maybe. But then again, note to self, don't bring in high school biology - the LSAT doesn't want me using my outside knowledge.

So here I buy your take on the answer choice a little more. In particular, yes, this seems to eliminate an alternate cause. But it just eliminates one random alternate cause, not many of them. So it's a strengthener, but not a very good strengthener. So I wouldn't cross this out, but I would definitely keep looking.

(C) is irrelevant - we don't care about the chemical components of G.

(D) actually does a good job of strengthening the argument, and I think this would have been another good one to consider choosing. This suggests that the G caused the preference because it predated the higher consumption of fat. This refutes the possibility that the higher G may be a result of the higher cause of fat intake rather than the cause. (D) is definitely better than (B) because it's much broader and goes to a more fundamental problem with the argument as it currently stands.

(E) is, like (C), irrelevant to our present concerns. It's way out of scope.

So (D) is our answer. I'd also point out more generally that (D) goes to a kind of assumption that is quite common and that we cover in Sessions 2 and 3 of the Atlas curriculum when we particularly focus on assumptions. That is, when you posit that A causes B, you are generally assuming that it doesn't got the other way, namely you assuming that B doesn't cause A. It would be worth giving this more thought and study, as this is a commonly tested concept on the LSAT.

Hope this helps, and thanks for the question. Answer choice (A) was particularly tricky, so I'm glad we got to talk about it.

Please let me know if you have more questions or comments!

[LSAT-Chang]

Hi aileen,
I also chose (A) for this one but I think I understand why it is wrong and (D) would be better. One question I had though was since this conclusion is claiming that A causes B, would an answer choice something like "rats craving fatty foods does not result in higher concentrations of galanin" which basically means B did not cause A be a strengthener? I honestly crossed out (D) because I thought it was just a restatement of the conclusion. If the author is stating that galanin causes rats to crave fatty foods, I would already think that the author is saying that galanin came before craving fatty foods (exactly what D says).. does this make sense?

[nbayar1212]

I don't quite follow the explanation for why A is wrong. A doesn't seem to affect the argument because it doesn't get us to the issue of what is causing the cravings in the first place, which the stimulus thinks is because of galanin. And if it does't do that, it's not strengthening. I dont' see how it weakens....am I missing something?

[tommywallach]

Hey Nabayar,

I'm confused by your comment. You don't understand why (A) is wrong, but then you say that (A) doesn't affect the argument. Obviously, if it doesn't affect the argument, it wouldn't be the answer. Then you say that it doesn't strengthen or weaken, as if those are the only two options. An answer choice isn't correct just because it doesn't strengthen or weaken. It could be irrelevant.

As always, all discussion should revolve around the core.

Conclusion: Galanin causes rats to crave fatty foods.

Premise: Fatty foods and galanin are correlated.

This question is a very straightforward type: it infers causation from correlation. Answer choice (A) doesn't have any relation to this causal connection. It brings up craving, which is irrelevant. Our argument compares rats who consistently (unchanging) eat fatty foods to rats who consistently (unchanging) eat lean foods. We don't care about the rats who switch back and forth.

Answer choice (D) helps solidify the causal connection, because now we know that high levels of galanin aren't causing the desire to eat fatty foods, which could easily have been the real causal connection.

As a comparison, low willpower and eating lots of ice cream are correlated. If I want to conclude that ice cream causes low willpower, it would be helpful to know that low willpower doesn't cause one to eat lots of ice cream.

Make sense?

-t

[nbayar1212]

Hi Tommy,

Sorry for the confusion. I simply want to know exactly why A is wrong. Aileen explained that she thinks A is wrong because it weakens the argument instead of strengthening. I said that I don't understand how A can weakens the argument and think that it doesn't have an effect at all and wanted to know if I am missing something (which your post clarified).

The reason I care is because had this been a weaken question, I would want to know if A logically weakens the argument.

I've been told that its just as important to know why the wrong answers are wrong as it is to know why the correct answer is correct and my question was within this spirit.

Thank you!

[WaltGrace1983]

I will try and help. I picked (A) and wanted to give further validation to my flawed thought process.

Rats who chose fatty foods had more galanin than rats who chose lean foods
→
Galanin causes rats to crave fatty foods

We can strengthen a causal argument by doing a few things:

(1) Show a bit more correlation by saying something like, "in another experiment, rats who chose fatty foods also had a high amount of galanin, much more than the other rats who chose lean foods." This strengthens because it simply gives us more reason - though a very weak reason - to believe that the conclusion is true. If I say that running causes better heart health and I show that people who run have better heart health then it strengthens the argument.
(2) Show that B does not cause A. If we say (galanin→crave fatty foods) then we could strengthen it by saying that ~(crave fatty foods→galanin). In other words, a right answer could say something like, "In another experiment, it was shown that fatty foods does not induce higher amounts of galanin" or something like that.
(3) Show that the absence of A is correlated with the absence of B. In other words, if ~galanin then ~craving fatting foods. A correct answer may also be something like "rats who had relatively lower amounts of galanin did not crave fatty foods."

With this in mind, we can attack the answers.

(A) This is by far the most tempting answer there is. Why? Because as was mentioned, it makes us think that the conclusion is something different than it actually is. The conclusion is that galanin causes rats to crave fatty foods. The conclusion is NOT that galanin causes rats to choose fatty foods. Why is this important? Because when we think about the ACTUAL conclusion, answer choice (A) doesn't do anything to the argument. It is simply saying that the craving doesn't cause OTHER things. In other words, if we appended this onto the conclusion it would look like this:

Galanin → Crave fatty foods ~→ choosing fatty foods over lean foods

Super tempting but overall irrelevant because we need to attack the gap between galanin and craving fatty foods. In other words, we want to attack this:

Galanin → Crave fatty foods

Rather than this:

Galanin → Crave fatty foods → __________

[Mab6q]

I just want to add that B was a good contender for me because it appears to be eliminating an alternative cause, that the fat in the brain did not lead them to crave fatty foods, but actually it falls short. If we knew that the rats that consistently choose fatty foods had more fat in their brain, that is okay because they are consistently choosing the fatty foods. As such, it makes sense that their brains are getting fatter.

[PhoebeL747]

So D is better than B because "establish temporal relationship" in a causal claim is stronger than "ruling out an alternative cause" ? Is this true in general or just in this question?

[VendelaG465]

Hey Nabayar,

I'm confused by your comment. You don't understand why (A) is wrong, but then you say that (A) doesn't affect the argument. Obviously, if it doesn't affect the argument, it wouldn't be the answer. Then you say that it doesn't strengthen or weaken, as if those are the only two options. An answer choice isn't correct just because it doesn't strengthen or weaken. It could be irrelevant.

As always, all discussion should revolve around the core.

Conclusion: Galanin causes rats to crave fatty foods.

Premise: Fatty foods and galanin are correlated.

This question is a very straightforward type: it infers causation from correlation. Answer choice (A) doesn't have any relation to this causal connection. It brings up craving, which is irrelevant. Our argument compares rats who consistently (unchanging) eat fatty foods to rats who consistently (unchanging) eat lean foods. We don't care about the rats who switch back and forth.

[b][u]Answer choice (D) helps solidify the causal connection, because now we know that high levels of galanin aren't [i]causing the desire to eat fatty foods, which could easily have been the real causal connection.[/u][/i][/b] -- I'm confused by this statement. The conclusion of the argument was to prove that galanin causes rats to crave fatty foods? but you stated that Galanin isnt causing the desire to eat fatty foods??? I also saw D weakening the argument b/c it was saying that the levels of G were already existing prior to the consumption of fatty foods so wouldnt this destroy the relationship ?

As a comparison, low willpower and eating lots of ice cream are correlated. If I want to conclude that ice cream causes low willpower, it would be helpful to know that low willpower doesn't cause one to eat lots of ice cream.

Make sense?

-t

[ohthatpatrick]

Consider this analogy for a sec:
In an experiment, people who consistently bought Cheerios were found to be significantly more likely to use a coupon with their cereal purchase than were people buying cereals other than Cheerios. This fact strongly supports the conclusion that being a Cheerios-lover causes you to be a bargain hunter.

Think about how you might object to this argument.

These arguments we're considering all fall under the category of Causal Arguments:
- the author presents a Curious Fact as a premise
- the author's conclusion either explicitly or implicitly assigns a causal story that explains or interprets the Curious Fact

CURIOUS FACT: Why are Cheerios-buyers more likely to be using a coupon than other-cereal-buyers?

AUTHOR'S CAUSAL STORY: Being a Cheerios-lover causes you to be a bargain hunter, so these people were apparently searching for coupons that they could use to buy Cheerios as a discounted price.

Our job is always to ask these two questions:
1. Is there some OTHER WAY to explain the curious fact?
2. How plausible is the AUTHOR'S WAY of explaining it?


When the Curious Fact is a correlation, then the two most common OTHER WAYS to explain it are
1. reverse causality
2. third factor

If we said, "People who drive luxury cars are more likely to be wealthy than those who don't. Thus, driving a luxury car causes you to become wealthier."

We would probably say "No, dummy .... they were wealthy FIRST, and THEN came the luxury car. The wealth caused the luxury car, not the other way around." (reverse causality)

If we said, "People who drive luxury cars are more likely to own a second home than those who don't. Thus driving a luxury car causes you to want a second home."

We would probably say "No, dummy .... the luxury car isn't causing the second home. The underlying causal factor is these people are rich! Their wealth is separately causing them to buy luxury cars and to buy second homes. That's why luxury homes and second homes are correlated." (third factor)


In the Cheerios example, there was a correlation:
"Ppl who buy Cheerios are more likely to use a coupon than are ppl who buy other cereals. Thus, wanting to buy Cheerios causes you to want to use a coupon."

We'd say, "No, dummy ... the coupon came FIRST! What if Cheerios is the cereal that most frequently offers coupons? That would mean that people come to the store with the Cheerios coupon and then buy Cheerios since it'll be cheaper than a cereal for which they don't have a coupon. The coupon causes the Cheerios buying, not the other way around." (reverse causality)


When you're Weakening, you either
PROVIDE some other way to explain the curious fact
or
UNDERMINE the plausibility of the author's way

When you're Strengthening, you either
RULE OUT some other way to explain the curious fact
or
BOOST the plausibility of the author's way

In this argument, there is a correlation between "high galanin" and "chose fatty foods".
The author concludes that "high galanin causes them to crave fatty foods".
But what if she's got it backwards? What if craving fatty foods came FIRST, then came the higher galanin?

It's possible that fatty foods increase the amount of galanin in your brain.
In that case, rats that eat fatty foods would have higher galanin in their brain.
But the high galanin wouldn't have caused the eating of fatty foods; eating the fatty foods would have caused the high galanin.

This argument is vulnerable to this REVERSE CAUSALITY objection: "What if the eating fatty foods came first, and the high galanin came 2nd, as a result of (not a cause of) the fatty foods?"

(D) rules out that objection, by establishing that the high galanin came 1st.

We could similarly strengthen the Cheerios argument by saying
(D) The people who buy Cheerios did not already possess a coupon when they made the decision to buy Cheerios

When you see (D), or when you're reviewing this question later and thinking about why (D) is right, you want to be saying, "Ah, yes. This rules out the possibly of reverse causality by establishing that the supposed cause (high galanin) was already in place when the supposed effect (craving fatty foods) transpired."

Hope this helps.