#14 - Researchers recently studied the relationship between

[Administrator]

Complete Question Explanation

Question #14: Flaw in the Reasoning—CE. The correct answer choice is (C)

Here, the author makes a flawed causal argument. The stimulus describes a recent study into the
relationship between diet and mood. In this study, researchers considered 1,000 adults, a sampling
that we are told was diverse. The researchers found a positive correlation between people eating
chocolate and the likelihood that they would feel depressed, meaning that the people who ate the
most chocolate were most likely to feel depressed. Based on this correlation, the author comes to a
strongly worded causal conclusion, that “by reducing excessive chocolate consumption, adults can
almost certainly improve their mood.”

This argument is flawed because it improperly reaches a causal conclusion based solely on evidence
of a correlation. We do not know whether the people in the study were depressed because they ate
chocolate or whether they ate chocolate because they were depressed. Further, we do not even know
which came first, the depression or the chocolate. Our prephrase is that the correct answer choice
will describe the author’s flawed causal inference based solely on evidence of a correlation.

Answer choice (A): This answer choice is incorrect because it describes the evidence relied on by the
author as being causal, when it was not. The author’s only evidence was that of a correlation. This
answer choice was attractive to those who recognized that the argument’s flaw was causal, but were
in a hurry to simply pick an answer choice and move on without considering the entire context of the
answer choice and the other answer choices as well.

Answer choice (B): This answer choice describes an overgeneralization from a potentially
unrepresentative sample. However, the stimulus was careful to tell us that the sample was diverse.
While the sample’s diversity does not guarantee its representativeness, the fact that the sample
was diverse reduces the chances that it was unrepresentative, and we cannot say that the sample is
unlikely to be representative. This answer choice was attractive to those who are familiar with the
LSAT’s propensity to misuse survey evidence.

Answer choice (C): This is the correct answer choice, because it describes the author’s mistake of
inferring causation from evidence of a correlation.

Answer choice (D): Here, the answer choice is incorrect because it describes a flaw in conditional
reasoning, while the flaw was causal.

Answer choice (E): This answer choice is inconsistent with the stimulus, because the conclusion in
the stimulus was not vague.

[LustingFor!L]

Can this question be diagrammed as conditional? I incorrectly chose answer choice D. I thought something was happening between A and C, but couldn't decide between them.

[Kristina Moen]

Hi LustingFor!L (nice name!),

The stimulus does not contain conditional reasoning. However, it does contain cause and effect reasoning (or causal reasoning). I know that it contains causal reasoning because of the conclusion that "By reducing excessive chocolate consumption, adults can most certainly improve their mood." The author is concluding that excessive chocolate consumption causes depression. He bases this off of a study that showed a correlation between chocolate and depression. "It was found that those who ate the most chocolate were the most likely to feel depressed" is stating a correlation - two events (depression and chocolate) are occurring at the same time. Thus, Answer Choice (C) is correct because it describes a flaw in causal reasoning.

Answer Choice (A) also describes a flaw in causal reasoning, but the author does not conclude that reducing chocolate will eliminate depression. He concludes that reducing chocolate will improve mood. Also, he does not infer his conclusion from the "fact that one substance causally contributes to a condition" (i.e. chocolate causes depression). He's not told that fact at all! That's the flaw of his argument. He draws a conclusion about causation from mere correlation (two events happening at the same time).

The "study" is a red herring. I perked up when I read that there was a study. Studies can use unrepresentative samples, be biased, have inaccurate results, etc. However, the stimulus stated that the study used a "diverse sample of 1,000 adults." The conclusion was also about adults. If the conclusion had been about children or about some other group (candy makers, for example!), then it would be suspect. The key here is that the population in the study matches the population discussed in the conclusion. So Answer Choice (B) is incorrect.

Answer Choice (D) is incorrect because it describes a flaw in conditional reasoning, and there is no conditional reasoning in this stimulus. "People who" can be a Sufficient Condition Indicator, but not when followed by words like "most likely." Then the relationship is not airtight. There could be people who ate excessive amounts of chocolate who were not depressed (lucky them!). With conditional reasoning, one condition is ALWAYS present (hence, necessary condition) with the other condition.

[adlindsey]

I keep getting questions like these that have causality and correlation wrong. I always have them between two contenders and chose the wrong one. What's a way to discern correlation from causality? Thanks

[Adam Tyson]

Conclusions about causality usually follow from premises about correlation, adlindsey. Correlation is just two things happening together - more of X happens along with more of Y (a positive correlation), or as X increases, Y decreases (an inverse correlation). When authors present claims about correlation, don't make any assumptions about causation yourself, but wait to see if they do. If they do not, then the argument isn't causal! It's when they do make such claims, saying that one of the correlated things is having an impact on the other (with language like "leads to" or "responsible for" or "induces", among others), that the argument becomes causal, and that's when you bring out the big guns to deal with it: alternate causes, cause without effect, effect without cause, reversed cause and effect, or data problems.

Here's the short version: correlation is just two things happening. Causation is one thing making another thing happen.

[Lsat180Please]

Hi! What would the flaw that answer choice E is describing look like? "the conclusion is worded too vaguely to evaluate the degree to which the premises support the truth of the conclusion". Thank you!

[Adam Tyson]

Honestly, 180Please, I don't know! I don't think we have ever seen that as an answer choice, right or wrong, other than in that one question, and I am having a hard time coming up with a hypothetical argument where that answer would make sense. But, it would have to be some situation where the argument could be good or could be bad, depending on how you interpret the conclusion, and the conclusion would have to be so poorly worded that you couldn't determine which way to interpret it. It would probably hinge on some undefined term being used, or some uncertainty as to which of two or more things the author was referring to.

I wouldn't worry about it too much, though, as you are unlikely to see something like that again, and if you do you can focus on eliminating the wrong answers and matching your prephrase. As long as you have some contender that matches your prephrase well enough, then you can pick it, and if you have eliminated four answers and are stuck with one like this that you cannot eliminate for some reason, pick it!

[davidp95]

My question: when people use the word "the fact" or "evidence" they are referring to the premise in the stimulus?

I believe that some have already answer this above but I would like to ask about use of the phrase " the fact" in answer choice A. "the fact" that is interpreted in this answer choice is the wrong interpretation of what was stated in the stimulus from my understanding. The "real fact" is there was no causation stated -- just a correlation.

However, the author interprets this as causally relationship to create a causally conclusion. That is my interpterion of answer choice A based on what other have said above as well as from reading it again. I just want to know for future reference on how to interprets words like fact or evidence in answer choices.

[Robert Carroll]

davidp95,

Premises and conclusions (and even unrelated things in stimuli) can all be facts. "Fact" is an extremely generic word. It's not the word" fact" that you should be focused on in answer choice (A), but the words indicating which "fact" is premise and which conclusion. "...infers from the fact..." What an argument is inferring FROM is a premise. The thing which is infers from the premise(s) is the conclusion. Answer choice (A) is claiming that the premises established causation. You're right - they didn't. The premises established a correlation, and the conclusion infers causation from that. So answer choice (A) is saying something that didn't even happen - never a good thing for a Flaw in the Reasoning answer choice.

To answer your further questions, look at how the word "fact" is used in each answer, when you see it used. It's almost like a pronoun. "Tim invited Eric, but he couldn't go." Who's "he"? Since Tim sent an invitation, I think he could probably attend whatever the event was! So "he" is probably "Eric." On the LSAT, how is the "fact" described in the answer choice?

"Infers from the fact that Y is true that X is also true" means that Y is the premise and X is the conclusion.

"Infers a fact about a whole from claims about the parts of that whole" means that the "fact" about the whole is the conclusion - it's what IS inferred, not that FROM WHICH something else is inferred.

Robert Carroll

[davidp95]

Thank you so much for the explanation Robert! This makes it a bit more clear when trying to understand answer choices