#20 - Polling data reveal that an overwhelming majority of

[Administrator]

Complete Question Explanation

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

This is the hardest question in this section, primarily because one of the wrong answer choices is
quite attractive. The argument claims that because most nine-year-olds correctly identify the logos
of major cigarette brands but very few nine-year-olds smoke, there is little connection between logo
recognition and smoking. Abstractly, the argument attempts to show that a possible cause (logo
recognition) does not have an expected effect (smoking).

The question stem asks you to identify the answer choice with the most similar fl awed reasoning.
Keeping in mind the different tests for Parallel Reasoning questions, consider the following when
selecting an answer:

Match the Method of Reasoning: The argument asserts that a cause and effect relationship
does not exist, so the correct answer choice must feature a similar type of relationship.

Match the Conclusion: The conclusion is fairly strong—“there is little or no connection
between two items.” The correct answer must feature a similar idea.

Match the Premises: There are two premises, one of which addresses a poll (a survey or a
study would be similar ideas) and the other about results from that poll which indicate
that a possible cause is not having an effect.

Match the Validity of the Reasoning: In this case the question stem tells you that the correct
answer must contain fl awed reasoning.

Obviously, the poll proves little, because it refers to juveniles who cannot purchase their own
cigarettes, and ignores the potential effect that may occur by the time the child is old enough to
plausibly pursue obtaining cigarettes. Since you are asked to identify the choice that contains
similar reasoning, you should look for a response that refers to a group that has not yet had ample
opportunity to develop a response to a particular cause.

Answer choice (A): This is the correct answer choice. Similar to the stimulus, a causal relationship
is denied on the basis of a study. The conclusion, although worded differently, has the same meaning
as that in the stimulus.

Specifi cally, three months is defi nitely not enough time to infer anything about the long-term effect
of mercury poisoning, so this answer choice similarly does not cover enough time to rule out a
cause-effect relationship.

Answer choice (B): This choice introduces two potential causes—dreams and parental infl uence—
and asserts that one is more important to establishing an effect. The stimulus only involves ruling out
a single cause and does not posit another, so this response is incorrect. The intent of this conclusion
also differs from that in the stimulus.

Answer choice (C): This choice involves deciding which strategy—using fl uoride or avoiding
sweets—would have the greatest effect. However, the stimulus does not evaluate strategies or the
importance of multiple causal factors, so this choice is wrong.

Answer choice (D): This answer choice was, by far, the most popular wrong answer choice on this
LSAT. Most likely the cause of this popularity is that the wording of the conclusion is virtually
identical to that in the stimulus. So, the problem with this answer lies elsewhere.

One serious problem is that this answer switches terms from the premise to the conclusion. One of
the premises is about “average life span,” but the conclusion is about “good health,” and those two
concepts are not the same. The stimulus, on the other hand, used the same terms from premise to
conclusion.

Another problem is that this answer relates the group to an average (“average life span”) whereas the
stimulus related the group to a specifi c, defi nable result (“smoking”). This difference, while minor,
helps indicate that this answer is problematic.

Answer choice (E): This quite possibly reasonable argument assumes that command of the issues,
not knowledge of representatives’ names, is a more important factor. Since the assumption is not
entirely unwarranted, it is diffi cult to say that this choice is fatally fl awed, though it certainly would
be somewhat more strongly reasoned with the addition of another premise. In any case, the stimulus
did not involve a comparison of factors, so this choice is dissimilar and incorrect.

[jared.xu]

Hello,

I have a question from the Take-Home Test December 2004, LR 4 problem #20 (20. Polling data reveal…). I used Powerscore’s Parallel Reasoning Elemental Attack to attack this question. I eliminated every answer except D, but it ended up not being the right answer. Applying the first technique (1. Parallel the Reasoning), we could eliminate B, C, and E. The argument uses data to show that there is little or no connection between two phenomena. B, C, and E do not do that. Applying the second and third technique (2. Parallel the Conclusion 3. Parallel the Premise), we could eliminate choice A and gives us choice D. D’s conclusion parallels that of the stimulus because they both show that a connection or correlation does not exist, whereas A’s conclusion tells us that a concern about the long-term effect is unfounded. The premise of D also parallels that of the stimulus because they both first show with data that a large percentage of the subjects are a certain way (1st phenomenon), and then shows that most of the subjects are not a certain other way (2nd phenomenon), whereas A’s premise only gives a random number (1000 dolphins) and tells us there is no effect on the animals who were exposed to mercury. Therefore, I faithfully applied Powerscore’s Parallel Reasoning Elemental Attack, and got the wrong answer.

And I think I know why I’m wrong. First, we have to somehow realize that the “connection” in the conclusion of the stimulus is really a cause-and-effect relationship. Second, we have to realize that there is a time error in the stimulus that parallels the error in A. The effect of logos may not have effects on nine-year-olds now, but they may have an effect on them in the future, just as the effect of mercury may not have effects on the 1000 dolphins now, but they may have an effect on them in the future. Whereas the answer I chose D manifests a different error: the conclusion equates a long life span to good health. So it appears that following the Parallel Reasoning Elemental Attack will sometimes make us fall prey to LSAT traps. Could you please show us how you would apply the Parallel Reasoning Elemental Attack in this case (or the right way of approaching this type of parallel flawed reasoning) so that you would not fall prey to the trap, and at the same time would be able to perceive the time error and the hidden causal relationship in the stimulus? Thank you in advance for replying.

[Nikki Siclunov]

This is an excellent question, and shows some of the deceiving ways test-makers can word a correct answer choice.

First off, this is a Parallel Flaw question (not a typical Parallel Reasoning Q.) Consequently, you need to understand why the reasoning in the argument is flawed before you even approach the answer choices. As you said in the second half of your post, the error is temporal: perhaps a much greater proportion of those 9-year olds who recognize cigarette logos will start smoking when they turn 16. In Parallel Flaw questions, your most important job is to parallel the flaw of the reasoning contained in the stimulus: the Validity Test takes precedence over any other test in the Parallel Reasoning Elemental Attack. Answer choice (A) exhibits the same temporal flaw, since it is quite possible that mercury exposure has long-term effects that are not immediately apparent.

I wouldn't eliminate answer choice (A) based on the Parallel the Conclusion test. By telling us that a "concern is unfounded," the conclusion in answer choice (A) implies that small quantities of mercury do not have a long-term effect on dolphins - which exhibits the same error in reasoning as the conclusion in the stimulus. You are correct that the premises do not match exactly the pattern presented in the stimulus, but they are close enough: 1,000 dolphins is a large number, out of which none suffered an immediate effect from exposure to mercury. Likewise, the overwhelming proportion of 9-year olds who recognize cigarette brands do not smoke. One is a number, the other is a proportion, but the way in which the author uses this evidence is the same in both arguments.

[Nina]

If i have understood it correctly, the flawed pattern in the stimulus: just because it lacks evidence for the connection, thus there's no connection. So i think answer D conforms to the flawed pattern. But why is it incorrect?

Thanks a lot!

[Jon Denning]

Hey Nina - thanks for the question. This is the hardest question in this section, primarily because the wrong answer choice you mention is quite attractive.

The argument claims that because most nine-year-olds correctly identify the logos of major cigarette brands but very few nine-year-olds smoke, there is little connection between logo recognition and smoking. Abstractly, the argument attempts to show that a possible cause (logo recognition) does not have an expected effect (smoking).

First, we need to identify the flaw. Obviously, the poll proves little, because it refers to juveniles who cannot purchase their own cigarettes, and ignores the potential effect that may occur by the time the child is old enough to plausibly pursue obtaining cigarettes. Since you are asked to identify the choice that contains similar reasoning, you should look for a response that refers to a group that has not yet had ample opportunity to develop a response to a particular cause.

Answer choice (A): This is the correct answer choice. Similar to the stimulus, a causal relationship is denied on the basis of a study. The conclusion, although worded differently, has the same meaning as that in the stimulus. Specifically, three months is definitely not enough time to infer anything about the long-term effect of
mercury poisoning, so this answer choice similarly does not cover enough time to rule out a cause-effect relationship.

Answer choice (D): This answer choice was, by far, the most popular wrong answer choice on this LSAT. Most likely the cause of this popularity is that the wording of the conclusion is virtually identical to that in the stimulus. So, the problem with this answer lies elsewhere.

One serious problem is that this answer switches terms from the premise to the conclusion. One of the premises is about “average life span,” but the conclusion is about “good health,” and those two concepts are not the same. The stimulus, on the other hand, used the same terms from premise to conclusion.

Another problem is that this answer relates the group to an average (“average life span”) whereas the stimulus related the group to a specific, definable result (“smoking”). This difference, while minor, helps indicate that this answer is problematic.


So I hope that helps clear it up. Tricky answer in D, but still incorrect for a few specific reasons.

[Nina]

Thank you very much, Jon! It's all clear now!

[Jkjones3789]

Hello, With this parallel flaw question I actually thought that the flaw present was the error of composition or division not quite sure why I thought that. Could you kindly explain to me the flaw that is present in this stimulus and why the correct answer is the correct answer. I looked at another post but it didn't help. I went with D because I wrongly identified the flaw I suppose. Thank you so much

[BethRibet]

Hi JK,

Thanks for the question. The flaw in the original stimulus is that it draws a general conclusion about people in general, based only on the behavior of 9-year-olds. Since it is unusual for 9 year-olds to already be smoking, using them as the basis to assess smoking behavior at large is inherently flawed, and also misses the prospect that these same children, will over time, begin smoking. You can think of this is a kind of "sampling error" -- drawing a generalization about a broader population based on a sample that it is too limited or specific. It also bases the conclusion on too short of a time-period -- that is what 9-year-olds do right now, as opposed to what they may do in the next 10-20 years.

Answer choice A does something similar -- the question being contemplated is the "long-term" effects of mercury exposure. The answer choice draws a conclusion based on only the measured effects of 3-month exposure, but it may certainly be true that over time, dolphins (like 9-year-olds now) will eventually display more harmful or demonstrable effects.

Hope this helps!
Beth

[lilmissunshine]

Hi Beth,

Thank you for your explanation. Can we say the (D) also deals with "sampling error", because the premise talks about "men" while the conclusion extends it to all genders?

Many thanks!

[Adam Tyson]

I think that's another good reason to toss out this otherwise attractive answer, lilmiss! Thanks for pointing out that additional detail that shows this answer to be a mismatch.