#21 - Prolonged exposure to sulfur fumes permanently damages

[Administrator]

Complete Question Explanation

WeakenX, CE. The correct answer choice is (A)

Some had difficulty finding the conclusion in this stimulus. The conclusion, appearing in the first sentence without any traditional indicator words, is that “prolonged exposure to sulfur fumes permanently damages one’s sense of smell.”

The support offered for this conclusion is a study involving 100 workers from sulfur-emitting factories. These workers were provided various chemically reproduced scents, which they were asked to identify. The workers successfully identified only 10 percent of the scents. In comparison, a control group of 100 workers from “other occupations” were able to identify 50 percent of the scents.

Based on the relatively poor performance of the factory workers, the author reaches a causal conclusion, that prolonged exposure to sulfur fumes caused the workers’ poor performance and, more generally, permanently damages one’s sense of smell. However, there are several questions left unanswered by the argument. For example, what are the “other occupations” held by the control group workers? Why did the study use chemically reproduced scents, and what effect did that have on the test results? And, as with any study offered as evidence on the LSAT, we need to be watchful for other, as yet unstated flaws in the study methodology.

The question stem establishes this as a Weaken—Except question. The four wrong answer choices will attack the causal conclusion, while the correct answer choice will have no effect on the conclusion, or could strengthen it.

Answer choice (A): This is the correct answer choice. This answer choice is tricky, because it plays on our concern about the impact of using chemically reproduced scents. However, it tells us that the scents closely reproduced the corresponding natural scents, even if they did not do so perfectly. So, this lack of perfection may account for the poor results even among the control group, which correctly identified only 50 percent of the scents. However, it does not explain the difference between the 10 percent factory worker result and the 50 percent control group result. And, it does not provide any reason other than the effects of exposure to sulfur fumes to explain the factory workers’ worse performance. Because this answer choice does not weaken the conclusion, it is correct.

Answer choice (B): The stimulus told us that the factories emit sulfur fumes, and the whole point of the study was to determine the effect of the sulfur on the workers’ sense of smell. While we do not know the occupations of the other workers, it appears safe to assume that most of those workers perform their work in an environment with less noxious odors than those that occur in the factories. So, this answer choice weakens the conclusion by suggesting that the factory workers’ poor performance may have been caused by the testing environment, rather than the workers’ ability to smell.

Answer choice (C): If most of the members in the control group had previously participated in a study involving the identification of scents, then it is possible that their prior experience in some way improved their performance in this study. That possibility raises the potential of an alternate cause for the factory workers’ inferior performance.

Answer choice (D): If all of the factory workers participating in the study have been exposed to other noxious fumes in addition to sulfur, then it may be the case that one of those other fumes caused any lost sense of smell suffered by the workers.

Answer choice (E): A weakness in the study was that it did not merely task the subjects with being able to smell the scents, but also to correctly identify them. If the factory workers were less likely to have been exposed to many of the scents used in the study, then it may be the case that the workers can smell—they just lack the knowledge to identify what they are smelling.

[MikeRov25]

How does A not weaken the argument? If the scents were not perfectly reproduced then it would have made it more difficult to correctly identify the smell. I picked D because the fact that the factories emit other noxious fumes doesn't really have much to do with the argument in my mind.

[Adam Tyson]

Thanks for the question, Mike. Let me see if I can help.

First, let's talk about why D does weaken the argument, because on "Except" questions like this we are typical focusing our effort on the wrong answers, because the right answer will have no particular discernible characteristics other than "not" (in this case, "not weaken"). Much harder to tell what you are looking for if you focus on finding the credited response on these!

D weakens the argument by introducing possible alternate causes for our factory workers. The author wants us to believe that it's sulfur that is causing our workers to have less success at identifying the smells. He claims that sulfur has permanently damaged their smellers. But what if it was some other noxious vapors that were doing the damage? Maybe methane? Introducing a possible alternate cause is a great way to weaken any causal claim. With other fumes floating around, how can we be sure that sulfur is the culprit? We can't!

Now back to answer A, which has no effect and is thus the best one for a "weaken-except" scenario. What impact does A have? The smells are not perfect representations might make the study generally bad, but it doesn't do anything to harm the claim that sulfur has permanently damaged the factory workers' sense of smell. The workers are still doing much worse than the other folks at identifying the odors, and A tells us nothing about why the two groups are different. It might tell us why neither group did all that well, but does nothing to address the difference between the groups and nothing to dispel the idea that sulfur is to blame for that difference.

Since "sulfur did it" is what we are looking to not weaken, A is our best choice. It has no impact at all, and that's what we are typically looking for.

Check out some of our other resources on Cause and Effect reasoning, and you'll see more about the classic ways we can attack those stimuli.

Keep your nose up!

[jayzbrisk]

why does answer choice C directly weaken the argument? Don't we need to add in some outside evaluation/assumption that since they had previously participated in other studies with the identification of scents that somehow they had an advantage? (also logically this really seems odd.....they were somehow better because they had previously done this? what did they do after they had chosen the wrong smell? they taught their noses how to smell better?? wtvr it is, even if u make a case for it, seemingly this is definitely not a direct weakener )

Also, assuming that this it is still a weakener, then why cant answer choice A be a weakener as well? Maybe the fact that the smells were not perfectly reproduced helped the control group in some way or detracted from the factory workers? ( technically you can answer me that why should this have such an effect on each group that the difference in percentage is such a big range, but then why cant we do something similar with choice C?

[Adam Tyson]

Answer C weakens by proposing an alternate cause for the difference in the two groups, other than permanent damage by sulfur exposure. That alternate cause is familiarity - perhaps the members of the control group became more familiar with the smells as a result of their participation in the other tests? It can also be viewed as a different kind of causal-weaken answer, an attack on the data. If the control group had prior experience, it lessens their reliability as a control group, corrupting the data. Ideally, members of both groups would have had equal exposure, or lack thereof, to the smells being tested.

Answer C doesn't destroy the argument, of course, because it's possible that the members of the sulfur-exposed group also had prior exposure to these smells, perhaps in other tests too. But "destroy the argument" is too high a standard to set for a weaken question, and we should add information not provided to alter our analysis of an answer. On its face, with no outside assumptions, answer C should at least make us stop and reconsider the validity of the study to see if perhaps the prior experience of the members of the control group might have altered the outcome. That's enough of a doubt to at least weaken our confidence in the conclusion drawn in the argument.

Answer A does nothing to weaken the argument that sulfur exposure is responsible for the different results in the two groups. The question being tested isn't "how good are people at identifying smells?", but "why are these two groups so different in their responses?" Imperfect reproduction of real smells would matter if we were answering the first question, but it is not relevant to answering the second.

[Juanq42]

Hello,

How would one logically negate answer choice A?

"The chemicals used in this study closely reproduced the corresponding natural scents" ? (removing the phrase "not perfectly")

Since this is a weaken X question, the 4 incorrect answer choices will weaken and the 1 correct answer will either strengthen or in this case - had no effect?

Thanks for your help!

[Dave Killoran]

Hi Juan,

Thanks for the question! Hopefully you are just asking about how to negate (A), and not actually applying it here, since that technique is only for Assumption questions

That said, the operational phrase here is, as you saw, "closely but not perfectly." If you take away just the "not perfectly," you'd still have closely, and so you wouldn't have a negation. So, let's think about what the phrase, "closely but not perfectly" actually means, since that's what we are negating. If this was a 0-100 scale with 100 being perfect, "closely but not perfectly" would be something like 95-99 (give or take a few on the 95, this is just a rough example). So, the way to negate something like that is to say it's anything but that range, meaning the negation is either it's perfect (100) OR it's farther away (0-94).

In this sense, it's like negating the phrase "exactly one." The negation there is "NOT exactly one," which translates to 0 OR more than 1.

Last, the answer here probably provides some support since it shows the scents were reasonably close.

Thanks!

[juandresmc]

Hi, can anyone please explain why (B) is incorrect. I chose (B) because my reasoning was that since “the subjects in the study were tested in the environments where they usually work” (the factories’ workers in the sulfur environment and the others in a less nocive one) then a potential objection with regards to the testing facilities was dismissed, thus strengthening the argument.

Thank you very much.

Regards,

Andrés

[Adam Tyson]

Thanks for the question, Andrés! Actually, if we want the testing environment to be eliminated as a potential objection to the validity of the results, we would need both groups to be tested in the SAME facility as each other (preferably a neutral one, and also preferably one that is largely devoid of odors that might interfere). Putting the factory workers in their factory and the other people wherever they work might mean that different odors in their workplaces might have made the difference in their performance, rather than the condition of their smellers. (And in case you didn't know, sulfur fumes smell powerfully of rotten eggs. You'd by lucky to identify ANY other smell in a sulfurous environment!) So putting folks in their respective workplaces for the test radically undermines the reliability of the study. Control the environment by testing everyone in the same place.

[juandresmc]

Excellent, thank you very much Adam. Greetings from Guatemala!

Andrés