Q24 - Advertisement: Researchers studied a group

[giladedelman]

Not bad! Thanks for your post. Let me add my two cents:

The argument is flawed in two ways. First, just because there was a correlation between weight loss, on the one hand, and big breakfasts and high protein, on the other hand, doesn't mean there was a causal connection. Maybe people who exercise a lot tend to eat big breakfasts and eat more protein, but it's the exercise that's causing the weight loss. So we have the very common LSAT correlation-causation flaw.

The other problem, as you pointed out, is that the argument concludes that anyone who follows the diet will lose weight. Even if the causal connection is valid, it is not okay to go from "a group of people" to "anyone."

So (D) is correct because it weakens the causal connection, and suggests that at best, this will only work for some people.

Be careful with your explanations for (A) and (B). We're looking for a flaw, so it would make sense for the answer to go against the conclusion, no?

I would get rid of (A) because although it might give a reason that a different diet would contribute to weight loss, it doesn't affect the conclusion about the high-protein diet.

(B) again suggests that there might be other ways to lose weight, but that doesn't mean the high-protein-big-breakfast diet will or won't work.

(C) is tempting, but it doesn't really have any impact on the conclusion. It just says that there was another factor besides diet that contributed to weight loss. Okay, but will our protein-breakfast diet work?

(E) sort of gives a reason for the results described in the premise; it certainly doesn't undermine the argument.

Thanks for your explanation!


#officialexplanation

[jiyoonsim]

Here's how I viewed the question, so please comment if I'm missing anything. This question was tough due to the extremely wordy choices!

Stem:

1) Those who lost the most weight in the group got more protein than carb.
2) Those who lost the most weight in the group also ate their biggest meal early.
3) So anyone who follows our diet, which offers more protein than anything else and the biggest breakfast ever, will lose weight for sure.

Answers:

A) Wrong. Feeling fuller is irrelevant, since what we need to do is check the validity of the conclusion (does the diet work?). Besides, A is the opposite of conclusion. We need to focus on high protein diet, not high carb diet.

B) Wrong. Again, similar reason with A; B is going directly against the conclusion. Also, the stem is about "those who lost the most weight," yet this choice mentions "a few of the people...who lost significant amounts of weight."

C) Wrong. To be honest, this was my answer under timed condition This might be a weakener, but alas this isn't the weakener question. C's focus is on the people who increased their activity level thus lost more weight. The activity level is irrelevant to the question.

D) Right. The stem starts with people who lost the most weight in the group with the high protein diet, and uses it as a premise. Yet the argument says doing high protein diet will make everyone (anyone) lose the weight.
D points out the gray area - that is, those who followed the high protein diet yet didn't really lose weight as much as the premise people.

E) Wrong. The focus here is high-protein/low-carb diet and it's effectivity, not about when to eat the biggest meal.

[LSAT-Chang]

I would love to hear feedback on my approach to this problem..
I knew there wasn't actual conditional statements at play here, but I still diagrammed it just in case it might help me see something, which it did..

1st sentence: lost most weight --> more calories from protein than from carbohydrates and ate biggest meal early in the day

2nd sentence (conclusion): more calories from protein than from carbohydrates and eat biggest meal early in the day --> lose weight

So I saw this as a sufficient/necessary issue (namely illegal reversal), and so wanted to attack this by showing how even if you get more calories from protein than from carbohydrates and eat biggest meal early in the day, you may still not lose weight (since we know what happened when you lost weight, but we don't know what will lead to losing weight). And I thought (D) illustrated this nicely by showing the sufficient without the necessary. Does this make sense? Please give me any feedback!

[giladedelman]

Well ... not quite. As you pointed out, we don't have conditional statements here, so we can't talk about necessary and sufficient conditions.

But, I see where you're coming from: just because group X had attribute Y doesn't mean that if you have attribute Y, you're going to end up in group X. I just would be careful talking about necessary and sufficient conditions in the absence of conditional statements.

Thanks for your post!

[T.J.]

Thinking in terms of correlation might help answer this question, but the correlation might be a stretch.

Here is why:
The stimulus talks about those who lost the MOST weight instead of MORE weight, which we expect to see in a correlation. These folk might very well be the exceptions. In other words, it's also possible that the diet of more protein and less carbs does not really work. (D) hits the spot as it points out there is another way around.

What you guys think?

[oscey12]

This question seems easy if you don't let C tempt you. It looks like C provides an alternate explanation for why the people lost weight, suggesting that the proposed diet methods are not responsible. D, however, negates the conditional statement. I've seen correct answer choices be alternate explanations like in choice C, but does negating the condition just trump alternate explanations when that choice is available? Any help on that would be great.

[jo.li0627]

This question seems easy if you don't let C tempt you. It looks like C provides an alternate explanation for why the people lost weight, suggesting that the proposed diet methods are not responsible. D, however, negates the conditional statement. I've seen correct answer choices be alternate explanations like in choice C, but does negating the condition just trump alternate explanations when that choice is available? Any help on that would be great.

I have the same question. Anyone can help?

[tommywallach]

Pretty much, but I'd say it's a rare occurrence.

-t

[seychelles1718]

I eliminated B and C because I thought they don't help us figuring out whether high protein, big breakfast diet caused the weight loss. But upon review, I am confused... Can someone help me why B and C can't weaken the causality of the argument?

We can weaken a causal argument by referring to the alternative cause or covariation.
I think B is suggesting that when there was NO cause, the cause was still PRESENT.
Also, C is suggesting an alternative cause, which is increased activity levels.

[ohthatpatrick]

Other paths to losing weight cannot affect this author.

Her conclusion is simply
IF you do method X, you are SURE to lose weight.

The only way to beat her conclusion is to show that "Method X does NOT guarantee weight loss".

(B) doesn't take us any closer to that, because it's just discussing other people who used a different method.

(C) is somewhat tempting, because it seems to undercut the support the author had for Method X being the cause of weight loss. It sounds like "maybe the REAL reason the protein/breakfast people lost the most weight is that they exercised more". But this answer makes it seem like exercise has a positive effect on everybody. It's not saying "no the REAL difference between protein/breakfast people and rest was just more exercise".

It's saying "exercise had a positive effect for everyone". Since it's not distinguishing the group we're examining, how would it provide an alternate explanation for why the BIGGEST weight losers were protein/breakfast people? They just exercised more than everyone else? This answer doesn't tell us that.

(D) just flat out contradicts the conclusion, so it is by far the biggest Weakener we're offered.

(B) no effect, since it's fine if other methods ALSO help you lose weight.
(C) seems to have some effect, although it's not great at distinguishing biggest weight losers from everyone else.
(D) contradicts the conclusion.

So this is a case where (C) might have been acceptable if we had nothing else, but (D) unequivocally blows it out of the water in terms of weakening strength.

[seychelles1718]

Other paths to losing weight cannot affect this author.

Her conclusion is simply
IF you do method X, you are SURE to lose weight.

The only way to beat her conclusion is to show that "Method X does NOT guarantee weight loss".

(B) doesn't take us any closer to that, because it's just discussing other people who used a different method.

(C) is somewhat tempting, because it seems to undercut the support the author had for Method X being the cause of weight loss. It sounds like "maybe the REAL reason the protein/breakfast people lost the most weight is that they exercised more". But this answer makes it seem like exercise has a positive effect on everybody. It's not saying "no the REAL difference between protein/breakfast people and rest was just more exercise".

It's saying "exercise had a positive effect for everyone". Since it's not distinguishing the group we're examining, how would it provide an alternate explanation for why the BIGGEST weight losers were protein/breakfast people? They just exercised more than everyone else? This answer doesn't tell us that.

(D) just flat out contradicts the conclusion, so it is by far the biggest Weakener we're offered.

(B) no effect, since it's fine if other methods ALSO help you lose weight.
(C) seems to have some effect, although it's not great at distinguishing biggest weight losers from everyone else.
(D) contradicts the conclusion.

So this is a case where (C) might have been acceptable if we had nothing else, but (D) unequivocally blows it out of the water in terms of weakening strength.

Thank you so much for your explanation! So you said it's fine if other factors cause the same effect (weight loss). Is that because the stimulus compares the group who lost the MOST weight with others, unlike other typical causal scenarios where the study compares those who lost ANY weight vs lost NO weight at all? (Where the argument assumes that a specific factor is the ONLY cause of a certain effect)

If the argument instead compared the group who had lost ANY weight vs lost NO weight, then can we use covariation method, such as B, to weaken the argument?

I think my confusion regard B came from the fact that I oversimplified the argument as if it assumed high protein, big breakfast diet is the ONLY CAUSE of weight loss.

[ohthatpatrick]

The reason OTHER weight loss methods don't matter is the conclusion.

All we're ever doing in the Assumption Family is evaluating the truth value of the conclusion, in relation to the evidence.

The conclusion is that, "if you follow method X, you are sure to lose weight".

conc: EVERY PERSON who follows method X will lose weight.
anti-conc: AT LEAST ONE PERSON who follows method X will not lose weight.

That's the only court case we're adjudicating here. Has the author convinced you that EVERY PERSON who follows method X will lose weight?

You're getting lost in the weeds of, "I don't even know if he's convinced me that ANY PERSON who follows method X will lose weight. He presented an example of someone who followed method X and lost weight, but I can't know for sure that method X was the REASON that person lost weight."

That IS relevant. If we can debunk the author's supposed evidence that these outliers who lost the most weight did so BECAUSE of method X, then we have hurt the argument by calling into question the author's only evidence.

But if we do what (D) does, and we just supply an example of AT LEAST ONE PERSON who followed method X and didn't lose weight, then we won the whole case!

A typical causal argument would have a more flexible conclusion like "Clearly, eating more protein calories and eating a big early meal can impact weight loss".

========

As an aside ... phrasing the evidence as "the people who lost THE MOST weight used method X" is super weak as a correlation goes.

If I said, the person who made the MOST money in America last year went to Cornell,
it would be weird to suddenly say "Anyone who goes to Cornell will be sure to make a lot of money"

When you say "the outlier has this trait", you're really only getting one data point (or several, if a few people are tied for top).

Normally, correlations are broader averages ... "People who go to Cornell are more likely than those who don't to make over $100k per year".

So if you ever see an author appealing to only the extreme cases, LSAT is likely to test "was there a pattern there otherwise, or is it just a random coincidence that an outlier had that trait?"

Check out this problem:
https://www.manhattanprep.com/lsat/foru ... -t707.html

[seychelles1718]

Thank you so much for your explanation! So just to clarify what you've just said, the reason why we can't weaken the argument by using the covariation method is the way the conclusion is phrased, correct? Even though the argument has the correlation-causation flaw, because its conclusion is not worded as other typical causal arguments?

[ohthatpatrick]

Correct.

Similarly, if an author concludes something weird like,
"Clearly X could have been the cause of Y", that would be another case where you can't apply the boilerplate thinking.

Pointing out an alternative cause doesn't weaken that claim.

Opposing Counsel only wins if she can prove that "X could not have been the cause."

That's a harder case to win than whether X was/wasn't the cause.

[WesleyC316]

I was struggling between C and D, but I've figured it out.

Firstly, D is definitely the right answer, because it straight up negates the conclusion. The conclusion says anyone who follows the advice will lose weight, and D smashes it by stating that some people never have that result.

I couldn't eliminate C because it says "regardless of whether they got more calories from protein or from carbohydrates". I mean, it's even giving no regard to the calories, of course it points to the questionable causal relation stated in the stimulus, how can it not be the right answer choice? But then, I found out that C actually doesn't contradict the conclusion at all, because it is saying that those who exercise "lost more weight", whereas the conclusion just says following the diet will "lose weight". Of course one can lose weight by following the diet, and lose even more by exercising. From this perspective, we can see C doesn't hurt the argument at all, unlike D.

I have to give it to the question writer for this one. The difference is so subtle while crucial.

Hope this helps anyone who's struggling between C and D just like me