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#35732
Complete Question Explanation

Flaw in the Reasoning. The correct answer choice is (E)

We tend to approach strangers if the stranger is of our own approximate age, and most long-term
friendships begin by approaching a stranger. On that basis, the author considers it likely that longterm
friends are of the same approximate age.

It may be helpful to diagram the argument contained in the stimulus as if it contained conditional
reasoning. However, keep in mind that the relationships in each premise are less than absolute, due to
the use of such phrases as “likely,” “probably,” and “most.” Nevertheless, since our primary objective
is to understand the logical structure of the argument as clearly as possible, such a conditional
approach would be justified, albeit with a caveat.

The first premise of the argument can be diagrammed as follows:

..... ..... ..... StrangerSimilar Age = One is of a similar age as a stranger

..... ..... ..... CAStranger = Comfortable approaching stranger

..... Premise (1): StrangerSimilar Age :arrow: CAStranger (likely)

The second sentence contains two clauses: the first clause is the conclusion of the argument
(“therefore”), whereas the second clause is a premise (“since”):

..... Premise (2): Most Friendships :arrow: CAStranger

..... Conclusion: FriendshipsSimilar Age (probably)

You should immediately recognize that this argumentation takes the form of a Mistaken Reversal:
just because age similarity is often enough to make us feel comfortable approaching a stranger does
not mean that we only approach strangers of the same approximate age. The author is confusing a
condition sufficient to guarantee a certain outcome with a condition required for that outcome to
occur. Consequently, even if most friendships begin when someone felt comfortable approaching a
stranger, it is quite possible that not all long-term friends are of the same approximate age, because
one might feel comfortable approaching a stranger who is not one’s approximate age. This prephrase
reveals answer choice (E) to be correct.

Answer choice (A): This answer choice suggests that we only feel uncomfortable approaching
strangers:

..... ..... ..... Uncomfortable ..... :arrow: ..... Stranger

Clearly, this is not an assumption upon which the argument depends. Even if we sometimes feel
uncomfortable approaching people who are not strangers, this would not undermine the validity of
the conclusion. Hence, the author does not presume the statement in this answer choice to be true.

Answer choice (B): The author does not conflate the occurrence of a characteristic in most situations
with its occurrence in a particular situation. The characteristic in question (same approximate age) is
qualified by such terms as “likely,” “probably,” and “most” throughout the argument.

Answer choice (C): The comparative likelihood of approaching strangers vs. non-strangers whose
age is similar to ours has no bearing on whether most long-term friends are the same age as each
other. Even if one finds it easier to approach a non-stranger who ultimately becomes a long-term
friend, the two friends would still be of the same approximate age.

Answer choice (D): This is an attractive, but ultimately incorrect, description of the logical flaw in
this argument. Because the statement in it is phrased as an assumption (“presumes, without warrant,
that…”) there is an easy way to test if it is indeed something upon which the argument depends.
Apply the Assumption Negation technique and ask yourself whether the logical opposite of this
statement weakens the conclusion of the argument:

..... ..... ..... One sometimes approaches strangers even if one does not feel
..... ..... ..... comfortable doing so.

This statement would neither support nor weaken the conclusion of the argument, because merely
approaching strangers is not something that necessarily leads to long-term friendships; feeling
comfortable approaching a stranger does. So even if we sometimes approach strangers without
feeling comfortable doing so, and these strangers are not of our own approximate age, there is no
evidence that they would ever become life-long friends. Since the logical opposite of the statement
described in this answer choice does not weaken the conclusion of the argument, this statement is not
an assumption upon which the argument depends.

Answer choice (E): This is the correct answer choice. Based on the initial premise, it is entirely
possible that feels comfortable approaching a stranger who is not one’s approximate age. If a
friendship begins (as most friendships do), the friends would not be of the same approximate age as
each other, which directly undermines the conclusion of the argument.

Note that there are multiple ways to describe the same flaw in conditional reasoning. Compare the
following examples, all of which amount to the same description of a Mistaken Reversal:

..... The author treats something that is sufficient for bringing about a state of affairs as
..... something that is necessary to bring about that state of affairs.

..... From the assertion that something is often sufficient for a long-term friendship to
..... occur, the author concludes that the same thing is necessary for such friendships to
..... occur.

..... The author takes for granted that one is likely to feel comfortable approaching a
..... stranger only if the stranger is of one’s approximate age.

Because there are so many ways to describe a conditional reasoning flaw, it is important to prephrase
an answer describing a Mistaken Reversal but keep an open mind—do not let yourself get “boxed in”
the exact language of your prephrase.
 Nadia0702
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#12260
I can't for the life of me figure out this question. I've read the explanation, but it doesn't make sense to me. In particular, it scares me that the explanation says "You should immediately recognize that this argumentation takes the form of a Mistaken Reversal" because I don't immediately recognize it and don't recognize it even after reading the explanation :-?

Two questions in one post. I'm generally have a very hard time with recognizing conditionality in language. I can do it just fine in Games. I blame ESL, but given that blaming ESL won't make me better at it, I better find another way :-D Would tutoring help me with this? Or do you have other recommendations for how to improve at conditionality and "immediately" recognizing it? I struggle a lot on mistaken reversals/negations when language is involved.

Thanks for all your help PowerScore!

Nadia
 Steve Stein
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#12263
Hi Nadia,

Good question; that's a tough one, but it's much easier to understand the argument when it is broken down and slightly reordered:

Premise: If a person is roughly the same age, there is a greater likelihood of comfort approaching a stranger:

around same age :arrow: more likely comfort approaching stranger

Conclusion: Therefore, long term friendships (most of which resulted from comfort approaching a stranger) are probably between people of roughly the same age:

LT friendships :most: comfort approaching a stranger :arrow: around same age

As for the difficulty noting the presence of this type of conditional reasoning, you are in very good company--for many students this is one of the most difficult aspects of the test, which is probably why conditional reasoning appears so often on the LSAT. There are a few things you might look for: indicator words that commonly introduce sufficient and necessary conditions (if...then, only if, etc.) as well as repeated conditions ("around the same age" and "comfort approaching a stranger" are each mentioned twice in one short stimulus).

I think you'll find that the more you practice the more quickly you will recognize what and how to diagram. I hope that's helpful! Let me know.

Thanks!

~Steve
 David Boyle
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#12264
nadia.a.wehde wrote:I can't for the life of me figure out this question. I've read the explanation, but it doesn't make sense to me. In particular, it scares me that the explanation says "You should immediately recognize that this argumentation takes the form of a Mistaken Reversal" because I don't immediately recognize it and don't recognize it even after reading the explanation :-?

Two questions in one post. I'm generally have a very hard time with recognizing conditionality in language. I can do it just fine in Games. I blame ESL, but given that blaming ESL won't make me better at it, I better find another way :-D Would tutoring help me with this? Or do you have other recommendations for how to improve at conditionality and "immediately" recognizing it? I struggle a lot on mistaken reversals/negations when language is involved.

Thanks for all your help PowerScore!

Nadia
Hello Nadia,

If you can reduce something to an if/then situation, then you could consider it conditional reasoning. (Unless it's causal)
Tutoring may help, possibly. But if you just try seeing if something can be reduced to an "if A, then B" situation (even if the words "if" or "then" don't appear), that may help a lot.

As for problem 24: you have my sympathy. I suspect that LSAC is trying to make things trickier these days in sufficient/necessary questions, so that answer choice E, "fails to address whether one is likely to feel comfortable approaching a stranger who is not one’s approximate age", is one of the sneakiest ways I've ever seen to imply problems like Mistaken Reversal.

It looks like MR is the problem in the stimulus, since what's basically going on is,

"approximate age ---> comfortable" (AA ---> C), therefore
"comfortable ---> approximate age" (C ---> AA).

Which is a MR, of course.

Answer choice E brings up that there may be many ways to become comfortable besides approximate age. Which is one of the basic problems with Mistaken Reversals in general, i.e., there may be many "A's" which can lead to a particular "B". Say, ice cream may make me happy, but so may a Snickers bar. Many different A's may lead to a B, so you can't say that B ---> A, since there may be many different types of A.

Sorry about the Halloween horror of question 24! Yes, it is difficult.
Hope that helps,

David
 Jkjones3789
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#16630
Hello, I tend to have problems with Flaw questions and find this pretty confusing. I went with B but the answer is E. Could you please explain this for me. Thanks
 Adam Tyson
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#16681
On this question I start my analysis by recognizing the conditional nature of the argument, indicated by the all-important word "if" in the first sentence. That first sentence could be diagrammed this way:

SAA (same approximate age) -> probably C (comfy)

The last phrase tells us that C, the necessary condition, probably happened in most long-term friendships, and then concludes (in the previous phrase) that most long term friends are probably close in age (the original sufficient condition). That is:

C -> probably SAA

See the mistaken reversal? Now I know I am looking for a mistaken reversal in my answer choice. Sadly, they don't use those key words like "sufficient" and "necessary" to help me find it! However, we don't need them - when you have a conditional flaw you can analyze it by just remembering that the necessary condition (comfy) can happen whether or not the sufficient does. In other words, "couldn't you also be comfy even if not the same age?" That gets you to answer E.

Answer B doesn't describe what happened in the argument. The author didn't presume that a characteristic IS present, but only that it is PROBABLY present. That's generally good logic - if a characteristic is present most of the time, then it is probably present (more likely to be present than not).

Hope that helps!
 mpoulson
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#23716
Hello,

Despite the analysis provided, I have trouble recognizing that the conclusion is a mistaken reversal. What language makes it clear that the sufficient or necessary condition are reversed? Also how does this lead to answer E? Also is there an alternative way to attack this problem or get to the same answer?

- Micah
 Nikki Siclunov
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#23805
Hi Micah,

Both Adam and Steve are spot-on in their analysis of this (admittedly difficult) problem. Let me weigh in, in the hopes of clarifying what's going on here.

The author begins by observing that we tend to approach strangers if the stranger is of our own approximate age. It may be helpful to diagram the conditional reasoning in this statement, even though the relationship is less than absolute, due to the use of such phrases as “likely,” “probably,” and “most":
  • Premise (1): One is of similar age as a stranger :arrow: Comfortable approaching stranger (likely)
Apparently, most long-term friendships begin by approaching a stranger. Great: we must have been comfortable approaching that stranger when we first met them. Does that guarantee, however, that long-term friends are of the same approximate age, i.e. that they began when we approached a stranger who is of our own approximate age? Not necessarily. Just because age similarity is often enough to make us feel comfortable approaching a stranger does not mean that we only approach strangers of the same approximate age. The author is confusing a condition sufficient to guarantee a certain outcome with a condition required for that outcome to occur - an error otherwise known as a Mistaken Reversal. Even if most friendships begin when someone felt comfortable approaching a stranger, it is quite possible that not all long-term friends are of the same approximate age: what if we also feel comfortable approaching strangers who are much younger or older than we are? This prephrase reveals answer choice (E) to be correct.

Hope this helps clear things up!
 mpoulson
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#24006
It does thank you.
 hrhyoo
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#71908
Hi Powerscore,

I now recognize and understand that the flaw here is the mistaken reversal, but I am not convinced that the answer choice B is incorrect. Here is my reasoning:

1. A characteristic present in a situation - feeling comfy approaching if same age

2. That characteristic present in most similar situation - most L/T friendships among same age in most similar situations such as feeling comfy approaching if same age.

Please help!


Hanna

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