Q20 - Pretzels can cause cavaties

[cyruswhittaker]

For this question, I initially chose C but have a better idea of why A is correct (uses individual correlations to form an unwarranted correlation between distinct groups), but could someone help me to understand what C is actually saying?

[tamwaiman]

Not very sure, IMO (C) is something like, the sugar substitute is harmful to diabetes, hence the sugar substitute is harmful to every patient who has insulin-related disease.

[tianfeng102]

In this question, there are two categories: pretzels and caramels; there is one correlation: the longer in contact with teeth, the greater the likelihood for cavity.

This correlation holds true within each category (apple vs. apple; orange vs. orange). But the same correlation is not necessarily true to hold across categories (apple vs. orange).

Thus, choice (A) treats a correlation that holds within individual categories as thereby holding across categories as well points out the flaw of this argument.

As to choice (C), I don't think there is a general claim being made in the argument. It's more like a specific deduction based on a few premises.

[griffin.811]

I think I have this down:

(A) says treats a correlation within individual categories as thereby holding across (other?) categories as well.

The first part, the correlation within individual categories, is:

1. the longer pretzels in contact with teeth, the better chance of producing cavities. And...

2. the longer caramels in contact with teeth, the better chance of creating cavities as well

(the categories referenced in answer A are caramels and pretzels. The correlation, time on teeth and cavities)

The second part is:
Holding (correlation) across other categories. In this case, because caramels are on teeth for a shorter amount of time (if we can even assume that this is what is meant by dissolves quicker) than pretzels they are less likely to leave cavities than pretzels are.

The issue: I'll use an analogy - the stronger A's muscles, the more A can lift. Also, the stronger B's muscles, the more B can lift.

A's muscles are weaker than B's, therefore, A cannot lift as much as B.

There are many issues with this statement. Muscle strength isn't the only determinant in how much one can lift. Perhaps A has better form/technique that allows her to compensate for her lack of strength, there by enabling her to lift more than B.

[amuir101]

I understand why A is correct, but why is B incorrect? (Also, the question doesn't say is "most" vulnerable to)

Doesn't the argument rely on the ambiguous use of the term "eating?" The argument "says that since caramels dissolve more quickly in the mouth than pretzels do, eating a caramel is less....."

But when you eat a pretzel you do not necessarily dissolve it in your mouth (you can, but to say that eating and dissolving in your mouth a pretzel is synonymous is unwarranted).

However, the argument does just this; it treats dissolving a pretzel as eating it, and draws its conclusion based on that.

[sportsfan8491]

With regards to answer choice (B), I do not see a term being used in the stimulus twice and in different ways. Dissolve and eating represent two separate ideas and they are different terms from each other.

Ambiguous word usage occurs when you allow the meaning of a word or the idea that a word represents to change in the argument. A great question I recall has to do with maturity and voting. I think the argument talks about maturity from a physical perspective at one point and then switches its meaning to refer to psychological maturity. This would be an example of ambiguous word usage because maturity has changed in meaning throughout the argument. I don't see this happening anywhere in this argument.

Also, I think the real problem with answer choice (C) isn't the "general claim" portion but rather the part where it talks about classes. Aren't both of these items part of the same class, namely food? So wouldn't they only represent one class then? What I'm trying to say is that this answer is wrong because it completely misses the point because we are only dealing with one class, so it can't possibly describe a flaw in the argument. Also, take note of the fact that category isn't the same as class. They dropped a different "c" word in order to keep people honest and to notice the difference between category and class! After reading (A) some people might be tempted to apply the same classification of "category" to (C), but they're talking about "class" which is something completely different, so don't let them fool you with this little trick.

[tommywallach]

Great explanation, sports fan. There is no ambiguity here. Also, eating requires the dissolving of the food in the mouth. You can't just swallow it whole!

-t

[Mab6q]

The issue with this argument is that the premise gives one characteristic that is related to cavities -- the amount of time something stays in contact with teeth, then uses this to make a general point about cavities. The problem with that is that contact with the teeth may be one of several characteristics that are relevant.

Here's an analogous argument:

"Evidence:Ted has a better chance to get into law school with a higher GPA, and the same is true for Bill.

Conclusion:
Therefore, since Bill has a higher GPA than Ted, Bill has a better chance to get into law school."

Does the evidence prove the conclusion? No, because we know there are other factors that could influence which person has a better chance of getting into law school. Knowing that higher GPA is better for both people is not enough to prove the more general conclusion.

It's the same issue with this argument -- the evidence is about one aspect that leads to more cavities, then the conclusion is about more cavities in general. Maybe there are other reasons why caramel might result in more cavities than eating pretzels (maybe the sugar in caramel causes cavities!). The author supports his claim using specific examples that don't give the whole picture, and that's what (C) says.

In terms of (A) -- in the argument, there is a correlation made between longer on teeth and more cavities from petzels, then we are told that the correlation is also true for caramel. It's not a flaw that he talks about the correlation applying to both pretzels and cavities.

What (A) actually says is that the argument is flawed because the author tries to "prove" one correlation using another ("thereby" is the key word for seeing this) -- the author doesn't try to prove one using the other -- he simply states that both correlations do exist.

Tough question, but I hope that helps. Please feel free to follow up if I haven't addressed the specific issues you may have had.

As much as I love Mike Kim and all the great explanations he provided to the forums, I feel like this one should be removed because the answer IS A here.

[rinagoldfield]

THANKS so much Mab6q ! I’ve deleted the offending post. ☺ (Future readers: Mab6q pointed out a big error by an LSAT geek... good eyes )

I’ll add my own 2 cents to this question:

P1: The more pretzel-tooth contact, the greater the likelihood of a cavity
P2: The more caramel-tooth contact, the greater the likelihood of a cavity
P3: Caramels dissolve faster than pretzels

-->

C: Caramels are less likely to result in a cavity than a pretzel.

Well, wait a minute! There are so many other factors that go into cavity-creation. For example, sugar. This argument looks at one factor (time) within caramels and within pretzels. The author then unwarrantedly compares across caramels and pretzels using this single factor. In doing so, the author overlooks other cavity-causers that were controlled within each food, like sugar, but may be different across the foods. For example, maybe the larger amount of sugar in caramels will override the faster dissolve time.

Here’s an analogy:

P1: The more I smoke, the greater the risk of harm
P2: The more I sit around watching movies, the greater the risk of harm
P3: I watch more movies than I smoke

C: Movie-watching causes more harm to me than smoking.

Again, I’ve identified something within smoking and something within movie-watching, and then erroneously compared across smoking and movie-watching using this factor. I’ve again overlooked other factors that were controlled within each behavior, like carcinogens, that may differ across the behaviors.

(A) gets at this flaw. It points out the author incorrectly looks across categories.
(B) is incorrect – there is no such ambiguity.
(C) is incorrect because each food is not representative of a “class.”
(D) is incorrect because the author does not make a causal error here.
(E) will never be a right answer choice on the LSAT. We must accept premises as true.

Thanks again, Mab6q