This is a necessary assumption question, though the question stem is quite abrupt and may present some challenges. It’s asking for an assumption, but there is no explicit indication of whether it wants a sufficient or necessary assumption. We have to really understand the nature of our assumptions to see this is necessary rather than sufficient. While it may sound obvious, sufficient assumptions are not necessary: Just because an assumption would be sufficient to validate the argument does not mean that the argument is definitely making that assumption. Necessary assumptions, on the other hard, are necessary. The argument is bound to them and cannot hold without them. Because this question stem is asking for an assumption the argument is definitely and actually making, that is how we know we are looking for a necessary assumption rather than a sufficient.
The stimulus: Well that’s interesting. Caffeine can kill certain insects, or at least their larvae. Now it looks like we have an experiment which is looking into this phenomenon. We see a certain insect die when it ingests some substance which contains caffeine, among other things. We should be drawn to the phrase “in part” because it tells us that there’s other components to whatever we’re feeding these worms. We should immediately question how we know that caffeine, and not some other component of the substance, is responsible. If this argument goes on to draw a conclusion about the effects of caffeine, it’s going to be in trouble.
And that’s exactly what it does in the last line of the sentence, which is our conclusion. The grammar is really convoluted, though, so let’s break it down to determine exactly what the conclusion is. The main body of the sentence is just “This result is evidence for the hypothesis . . .” Which hypothesis? Well, the rest of the sentence specifies which one. But the main part of the sentence is our conclusion: The result is evidence for this hypothesis.
So this doesn’t go as far as it might have. It does not say, “Therefore, caffeine totally evolved as a defense against pests.” That would have been easy to discredit. Rather, it merely says that this experiment is evidence for such a hypothesis. Is it? Well, maybe. What is evidence? Evidence doesn’t have to be conclusive. It only needs to make a proposition more likely to be true. Because there are so many other things they’re feeding to these worms, this is really weak evidence, but despite its weakness, it may nevertheless qualify as evidence. It’s hard to say for sure though. Either way, this opens up a nice big gap with lots of assumptions.
The other observation we might make from this final sentence is the reference to “non-negligible quantities.” Do tea leaves contain non-negligible quantities of caffeine? This argument does not give us an answer. And even if we assume they do, was there enough tea powder in this concoction to deliver a non-negligible dose? Maybe, maybe not. We don’t know. This new term also introduces room for assumptions.
There is a lot going on in this stimulus, and we likely have not have identified every gap. We want to proceed with a POE approach on this one and see what the answer choices might offer up for us to consider.
Answer Choice (A) Sure, maybe. This strengthens the proposition that these plants have insecticidal qualities, but what we care about is caffeine and this does not narrow down which substance in these plants is actually doing the insecticide-ing. Maybe caffeine, maybe something else. Moreover, the hypothesis is addressing caffeine as an evolutionary function, which this does not seem to touch.
Answer Choice (B) This is an interesting suggestion, but it has a problem. Does it have to be “roughly equal” to the amount in the concoction fed to the worms in the experiment? I don’t think so. It could be way higher and we would expect that to do the job.
Answer Choice (C) I can see why this might be attractive. It establishes some link between caffeine producing plants and the pests, and that does appear important to a conclusion about caffeine as an evolutionary response. What if this were not true? What if caffeine producing plants simply don’t grow wherever these pests pose a risk? “Wherever” should give us pause, though. This is a more universal statement than I’m comfortable with here. I think a 99% match would still be pretty compelling. So this gets at something close, but it misses the mark.
Answer Choice (D) Okay. So the specific worm in our experiment is a tobacco pest. What if the tobacco plant doesn’t produce caffeine? That seems like it could be a problem. How can we say caffeine evolved as a defense against these pests if these pests feed off a plant that doesn’t produce caffeine? That might seem seem to break the relevancy of the experiment with any claim about caffeine as an evolutionary mechanism. But does it? It still establishes a sensitivity to caffeine among plant pests. The fact that tobacco may not have evolved that specific defense doesn’t necessarily mean that this can’t support a hypothesis that only relies on the fact that caffeine is an effective pesticide. If D were not true, it would certainly weaken the argument. But I do not think it would destroy it.
Correct Answer Choice (E) This has to be true. No evolutionary pressure; no evolutionary response. If caffeine producing plants have literally never been preyed upon by pests which are sensitive to caffeine, there’s no way this is an evolutionary response. We do need to be a little careful though. Remember, the conclusion is very precise. We are not concluding that these plants evolved caffeine as an evolutionary defense against pests. We are concluding that the experiment with the tobacco worm is evidence that they might have. While this answer needs to be true for this to actually have been an evolutionary response, does it have to be true for this experiment to lend the hypothesis support? Yes. If the hypothesis is disproven, then there is no observation which we would say qualifies as evidence to support it. The hypothesis must remain possible for this experiment to qualify as evidence.
We know this question is a sufficient assumption question because the question stem asks which of the answer choices “enable the conclusion to be properly drawn?”
Sufficient assumption questions tend to be very formal. We’re looking for a rule that would validate the conclusion, specifically by bridging the premise and conclusion through the rule. Not only are we extrapolating the rule from our argument, but we’re plugging that rule back into the argument to make it valid. Our rule/prephrase will look like: if [premise], then [conclusion].
Our first sentence describes specific kinds of experiments and the observations from those experiments. The experiments were conducted with certain kinds of bacteria. They were placed around lots of nutrients and two things were observed: population grew (which makes sense, more nutrients = growth), and genetic mutation occurred at random. These observations are our premises.
The next sentence is the hypothesis/conclusion: based on these experiments, the author hypothesized that all genetic mutation is random. All? That’s a big jump from mutations in certain bacteria to all genetic mutations. “All genetic mutations” includes mutations that aren’t just bacteria, too. Our rule would look like: “If certain bacteria genetically mutate at random, then all genetic mutations are random.”
Remember, our paraphrase is meant to guide us through the answer choices. The answer choice may not mimic the paraphrase, but it should make the argument valid when we plug it back into the conclusion.
Correct Answer Choice (A) We know for sure that the genetic mutation did happen in our experiment, and with the dichotomy in answer choice A, we either have to accept that all mutations are random, or none are. Since we already have some random genetic mutations in bacteria in our experiments, we have to accept that all genetic mutations across lifeforms are random; accepting the latter wouldn’t make any sense and isn’t possible. In other words, if we plug this back into our argument, the conclusion is valid.
Answer Choice (B) Just because bacteria used in the experiments are common, it doesn’t mean that random genetic mutation occurring in this instance will occur in all other instances as well.
Answer Choice (C) We can’t trigger the sufficient condition in this conditional. With the information in the stimulus, we only can say that certain bacteria go through genetic mutation. This is useless.
Answer Choice (D) If we plug this back into the premises, given what we know about the massive jump the argument makes between the premise and the conclusion, this answer choice does absolutely nothing. It’s additional information that has no positive or negative bearing on the argument.
Answer Choice (E) Knowing that these bacteria are found in nature isn’t enough; we need to know about genetic mutation across life forms, not just bacteria.
We know that this is a Sufficient Assumption question because we see “which one of the following principles, if valid, justified the…conclusion” in the question stem.
Sufficient assumption questions tend to be very formal. We’re looking for a rule that would validate the conclusion, specifically by bridging the premise and conclusion through the rule. Not only are we extrapolating the rule from our argument, but we’re plugging that rule back into the argument to make it valid. Our rule/prephrase will look like: if [premise], then [conclusion].
The first sentence gives us a lot of information on pedigree dogs: pedigree dogs (including working dogs, like a shepherd or hunting dog) conform to org standards. We also know that these organizations specify the physical appearance needed for dogs to belong to a breed. The stimulus then says that the orgs don’t have standards for specific genetic traits. The author cites, as an example, traits that would have enabled dogs to do the work they were developed to do (like sense of smell or direction). This all sounds like important contextual information.
In the third sentence, we see “since,” a premise indicator. The author says that because the breeder will only maintain the traits specified by the organizations (premise), certain traits (like herding) risk being lost (conclusion). This seems like a logical conclusion based on the premise we just read, but it may not be our main conclusion. Let’s read on.
In our last sentence, the author claims these pedigree organizations should set the standard for working ability in dogs developed for work. First thing, this is the main conclusion; the whole stimulus is oriented towards this one statement. However, is this a valid conclusion? Well, why should the organization set these standards? Are they necessary for, as an example, an Australian Shepard who isn’t going to herd sheep? This is the gap in our argument.
Remember, we’re bridging this gap by forcing a conditional statement with our premise and conclusion: If [premise], then [conclusion].
The first two sentences help guide the rest of the information in the stimulus, but it’s really the third sentence that acts as the minor premise and major premise/sub-conclusion: working traits that certain dogs were originally developed for are at risk of being lost. Our conclusion is that these organizations should set requirements for the working abilities of working dogs. Together: If working traits that working dogs were originally developed for are at risk of being lost, organizations should set requirements for those abilities in those dogs. The correct answer doesn’t need to be a conditional statement, but it needs to have the level of certainty and language of the conclusion (in our case, prescriptive).
Answer Choice (A) This answer choice is wrong because it doesn’t address what our argument focuses on. This answer would come into play if setting standards for working traits risks the loss of other traits. Since we don’t know anything about what working traits could do to other traits, this is out.
Answer Choice (B) This is wrong because it’s only relevant to standards currently in effect; we’re talking about standards that are not and should be in effect.
Answer Choice (C) This is saying that organizations should make sure standards are respected; this isn’t relevant to our argument! We’re trying to argue for an additional category of traits to be included in the standard.
Answer Choice (D) Use the product/activity will eventually be put to? It’s not said that working dogs will be used for their working purposes, only that those traits need to be retained.
Correct Answer Choice (E) It uses information from the premises (ensure that products can serve the purposes for which they were originally developed, e.g. herding, hunting) and echoes the prescriptive language in our conclusion (organizations should attempt). Even though this isn’t a perfect repetition of our prephrase, remember that our prephrase is meant to help guide us to the correct answer choice by making sure we understand and can extrapolate relevant information from the argument.
This is a sufficient assumption (SA) question, and we know that because of the language in the stem: “Which one of the following principles… would justify…”
Sufficient assumption questions tend to be very formal. We’re looking for a rule that would validate the conclusion, specifically by bridging the premise and conclusion through the rule. Not only are we extrapolating the rule from our argument, but we’re plugging that rule back into the argument to make it “valid.” Our rule/prephrase will look like: if [premise], then [conclusion].
Our first sentence is a prescriptive claim, with a concession: even though smoking is legal, smoking should be banned on flights. The first question we ask is: “Is there a reason this should be the case?” The next sentence attempts to give us an explanation: smoking exposes people to unavoidable harm. Our first sentence is the conclusion, and the second is the explanation/premise.
SA questions often take this form: the conclusion is that something should be done, and our premises attempt to support and validate this prescriptive statement, but it misses the mark. Why? Because the argument makes illicit assumptions.
Back to this stimulus. We could say: “Sure… the harm is unavoidable, but why should we punish the smokers? Why don’t we just prevent non-smokers from flying?”
The good news is that, in trying to make these arguments valid, the solution is simple: bridge your premise and conclusion through a rule: If [premise], then [conclusion]. Our premise here is that “smoking exposes people on planes to unavoidable harm” and our conclusion is that “cigarettes should be banned on all flights.” Our rule will look something like this: “If smoking on planes causes unavoidable harm, then smoking should be banned on all flights.” This is forcing our conclusion to be true by putting the premise and conclusion in a conditional relationship. We’re also trying to make sure that we retain the language/level of certainty in the conclusion when we create our rule. With the rule (or principle, to take the language of the stem) established, the sufficient condition is triggered by the premise and our conclusion is valid. Also a note, the answer choice may not be as straightforward as our prephrase. They could give us the contrapositive of the conditional, or introduce the necessary condition first, so pay attention.
Correct Answer Choice (A) This one perfectly mimics our prephrase. It’s broad, but that doesn’t matter because its scope includes our argument: People should be prohibited from engaging in smoking (or, legal activity) when (or, in those situations in which) that activity will harm people. The order might be confusing to some people, after all, the conclusion is introduced first in the sentence. However, because “when” is a group one indicator, this is correct. If you have trouble understanding this, review conditional logic in the core curriculum.
Answer Choice (B) This is incorrect because of the direction of the conditional statement. The “should be banned” and everything after the group 2 indicator “only if” should be switched. With the language in B, we can’t trigger the conditional and this leaves our argument untouched.
Answer Choice (C) The first half of the answer is pretty good! But “legal activity should be modified?” That’s very ambiguous. Remember, in SA questions, we strive for 100% validity. What would modifying the legal activity of smoking look like? We can’t just assume modifying means banning it.
Answer Choice (D) Read this answer choice very carefully – it’s very wordy, but it’s essentially saying that people should be excluded from situations in which their activity harms others in those situations. With respect to our argument, that would mean smokers should be excluded from flying. This is incorrect because our conclusion claims that smoking should be banned, not smokers.
Answer Choice (E) This is similar to C in that the first half of the conditional is okay. But when we get to the necessary condition, the answer choice pivots. We’re trying to make smoking illegal in airplanes and our answer choice is saying that it should be legal in all situations. This actually weakens our argument.
This is a flaw/descriptive weakening question, and we know this because of the question stem: “…reasoning is most vulnerable to which one of the following criticisms?”
Let’s take a look at the first sentence. Despite his usually poor appetite, Monroe enjoys three meals at Tip-Top but becomes sick after each meal. Immediately, this sounds like a correlation: the phenomenon of becoming sick occurring with the phenomenon of eating a Tip-Top.
The second sentence is pretty straightforward: it’s a list of each meal he ate at the restaurant. Interestingly, they’re all very large meals, especially for someone who generally has a “poor appetite,” and they all have a side of hot peppers. Both of these look like premises. They’re both statements of facts.
What does our conclusion say? Since all three meals had peppers (premise), Monroe concludes that he became ill solely due to Tip-Top’s hot peppers. Solely? Not only is he assuming causation, but it’s very restrictive. Sure, hot peppers may have contributed to feeling ill, but what about eating this kind of unhealthy food? What about eating this amount of food? What if he’s lactose and fried-food intolerant? The causal relationship he establishes is shaky because “solely” is an unwarranted restriction in the implied causation.
Answer Choice (A) It’s hard to establish whether or not it’s descriptively accurate because “too few” is pretty subjective. We sometimes know after one meal why we got sick. Additionally, he still got sick after each of these three meals, so there must be some reason he’s getting sick. But let’s just say it is accurate. Is this the flaw? No! This isn’t a sample size issue; it’s the restriction in the causal relationships that’s an issue. It could be that hot peppers partially contributed to him feeling ill, in which case 3 meals isn’t “too few.”
Answer Choice (B) This is not correct because it’s descriptively inaccurate. We know explicitly from the stimulus that he became ill after consuming each the meal (read first sentence).
Answer Choice (C) This is not descriptively accurate because, although he may want to continue dining at Tip-Top, there is no evidence of this biasing his conclusion. Also, if he wanted to continue eating at Tip-Top, it would make more sense for him to blame his illness on something outside Tip-Top’s control/menu.
Answer Choice (D) This is descriptively accurate, but it’s not the flaw. Just because hot peppers didn’t make everyone else sick, that doesn’t mean it cannot make Monroe sick. Other people’s reaction to the hot peppers is not relevant to the conclusion Monroe draws, and even if this was established, it would not strengthen Monroe’s position.
Correct Answer Choice (E) It demonstrates that his causal relationship is unwarranted by introducing an alternative cause, which we know is one of three ways to disprove a causal relationship.
This is a Flaw/Descriptive Weakening question and we know this because of the question stem: “The argument is most vulnerable to criticism on the grounds that…”
With a flaw question, we’re trying to identify reason(s) the conclusion wouldn’t follow the premises. In other words, we’re trying to extrapolate and explain why the stimulus is flawed, and why the premises don’t support the conclusion. Remember, there could be multiple flaws.
The first sentence goes into percentages. Whenever this happens, it’s always a good idea to pay close attention to what subset or group of individuals/items is being discussed. Here, we know the group is voice recording taken from small planes involved in relatively minor accidents. Great! What about this group? Over 75% of the recordings showed that the pilot whistled 15 minutes right before the accident. The rest of this percentage pie? Under 25% of the recordings when planes were involved in accidents did not record pilots whistling 15 minutes before the accident.
Two things should be going through our minds here: first, this sounds like a statement of facts, and is probably going to be a premise; second, this sounds like correlative language. If that’s the case, what can we draw from this statement? Only that these two instances are correlative! Remember that correlation does not imply causation.
The second sentence is very straightforward, probably a premise or context. At this point, it’s okay not to really understand what function it has in the argument; let’s put it aside and return to it.
Now we’re coming to our last sentence, and it starts with “therefore.” If I haven’t seen my conclusion and this starts with a conclusion indicator, I’m praying this is it. And it is! It’s a conditional conclusion, which means that we’re only concerned with instances where the pilot starts to whistle because that is when our sufficient condition is triggered. Okay, now on to the substance of the conclusion. Why should passengers take safety precautions when the pilot starts to whistle? Presumably, there would be a risk. What’s the risk here? According to this argument, and specifically the second sentence, the risks are the minor accidents that small airplanes are involved in.
The argument is making a jump from whistling to the accident but doesn’t explicitly relay what that relationship is. The part where I say “presumably, there would be a risk” is what the argument is assuming as causation. The argument is assuming that since accidents occur in over 75% of the voice-recorder tapes taken from small airplanes involved in relatively minor accidents where the pilot was recorded whistling 15 minutes prior, then it must be that whistling causes those accidents*.*
We know from the core curriculum that this line of reasoning is ridiculous. You cannot imply causation from correlation! There are a thousand different things that could have caused the accident independent of the pilot whistling. And there are many things we can point to that the argument overlooks. For example, what if most pilots whistle during flying—regardless of the size of the plane and the majority of them—and never get into accidents? What if pilots whistle all the time, but different things caused those accidents? The questions are endless. Now that we’ve identified a flaw, let’s get into the answer choices with our two steps: is this answer choice descriptively accurate? Is this the flaw?
Answer Choice (A) Accepting the reliability of the statistics given by the official is descriptively accurate, but this isn’t a flaw. Firstly, we have to accept the premises of this argument, which would mean that we have to accept the statistics. Second, the reliability of the statistic isn’t what makes our conclusion unsupported. This is out.
Answer Choice (B) Descriptively accurate, but not the flaw. This is trying to confuse you by bringing up statistics. This says in 25% of these accidents (where passengers did not hear the pilot whistle), the recommendation (take precautions once they hear whistling) wouldn’t help because they heard no whistling before the accident. So, what? The argument isn’t concerned about the safety of all passengers; it’s specifically talking about passengers who hear the pilot whistle.
Answer Choice (C) This is descriptively accurate, but again, it is not a flaw. Defining what small accidents are is not pertinent to the inadequacy of the support the premise gives the conclusion.
Correct Answer Choice (D) This is saying that the argument is ignoring the percentage of all small airplanes, including the planes that do not get involved in accidents, in which the pilots whistle. What this answer is trying to say is that the argument is only looking at planes that do get involved in small accidents. What about planes that don’t get involved in those accidents – it could be that the argument is overlooking the much more likely scenario that whistling is something pilots do very often during flights, and the correlation between accidents and whistling is a total coincidence.
Answer Choice (E) This is descriptively accurate, but it’s not the flaw. This answer choice forces the argument to consider the proportion of planes that get into accidents; for example, out of 100 small planes, 25 will get into accidents. So, what? This isn’t relevant to the conclusion, nor is it what makes the conclusion unsupported.
This is a Flaw/Descriptive Weakening question and we know this because of the question stem: “A flaw in the…reasoning…”
With a flaw question, we’re trying to identify reason(s) the conclusion wouldn’t follow the premises. In other words, we’re trying to extrapolate and explain why the stimulus is flawed, and why the premises don’t support the conclusion. Remember, there could be multiple flaws.
The magazine article talks about a new proposal by The Environmental Commissioner and that there is going to be a nationwide debate on them. These new proposals are called “Fresh Thinking on the Environment.” The tone in the next sentence is important: clearly, the article doesn’t think “fresh thinking” can come from the commissioner and therefore the proposal deserves a closer inspection. So far, both of these sound like premises.
The next sentence gives credence to the second sentence we just read: these proposals by the Commissioner are almost identical to Tsarque Inc’s proposals which were issued three months ago.
Before we read the next sentence, what can we conclude from just this information? Well, even though the Commissioner may have believed that his proposals were “fresh thinking,” we can conclude that the title is misleading. We could also say that conversations arising from the debate on the Commissioner’s proposals could be applied to the Tsarque Inc’s proposals.
What does our conclusion say? Since Tsarque Inc’s pollution is an environmental nightmare (premise), the magazine thinks the debate on the Commissioner’s proposals can end here. Note that the argument is jumping from Trasque’s actions to the Commissioner’s proposal. It’s fair to draw similarities between the two proposals since we know they’re identical – remember, we have to accept the premises. The problem is jumping from Tsarque Inc’s actions to Tsarque Inc’s/the Commissioner’s the proposal.
This is the problematic assumption: Trasque’s polluting tendencies are reflected in their proposals (and therefore the Commissioner’s proposal). The magazine article is using the actions of the company against the proposals, even though the content of the proposals could have nothing to do with those actions. In other words, this argument has an “Ad Hominem” fallacy, meaning that an attack directed at the person/organization rather than the position they take in their proposal. The magazine article tried to dismiss the proposal in a roundabout way rather than addressing the content directly. Now that we’ve identified a flaw, let’s get into the answer choices with our two steps: is this answer choice descriptively accurate? Is this the flaw?
Answer Choice (A) This is not descriptively accurate. Two things can be similar without one influencing the other. But for argument’s sake, let’s say this is descriptively accurate – after all, the two people involved in the proposals are close friends. Is this the flaw? Is the reason the argument is flawed because it assumes these influenced one another? No! The argument wants to dismiss the commissioner’s proposals by attacking Trasque’s actions, whose proposals (which are the same as the Commissioner’s) may not have any similarities to their actions.
Answer Choice (B) This is not descriptively accurate - nowhere in the premises do we see distortion.
Correct Answer Choice (C) YES! This is perfectly describing what ad hominem fallacies are.
Answer Choice (D) Emotive? There is no controversial language here. The tone suggest the magazine does not like what is said in the proposals, but it’s not using controversial language. This fails the first step - it’s not descriptively accurate.
Answer Choice (E) This is not descriptively accurate. The argument appeals to Tsarque’s actions; the reference to the chief could have been put there to throw us off, but the argument simply does not appeal to the chief’s authority.
This is a Flaw/Descriptive Weakening question, more specifically, we need to figure out why the therapist’s response to the interviewer is flawed.
Let’s look at what the Interviewer is saying. In his first sentence, he is talking about the therapist’s claims, saying that biofeedback, diet changes, and better sleep habits succeed in curing insomnia. This is a causal claim. In the next sentence, he elaborates on another claim: with rigorous adherence to the proper treatment, any case of insomnia will be cured. Another causal claim. There is a tone clue here: “You go so far as to claim that…” That makes me think this author doesn’t buy the therapist’s claims. I’m thinking these are both premises, since they represent other people’s ideas.
In the next sentence, we see a “yet;” there is a shift. We were talking about the therapist’s claims, now we’re going to be talking about something that’s probably at odds with the earlier claims. Reading on, that’s exactly the case: our author says that some insomniac patients do not respond to treatment.
So far, all of these sentences look like premises. No sentence is providing support to another sentence. The interviewer is outlining the therapist’s claims and then stating a fact. Well, how can we figure out what the argument is saying without the conclusion??
The conclusion here is implicit. We have enough tonal clues and claims to assume what the author probably thinks. His implicit conclusion is: the therapist’s claim (with rigorous adherence to the proper treatment, any case of insomnia is curable) isn’t realistic. Why? Take a look at that last sentence: “…some patients suffering from insomnia do not respond to treatment.”
The therapist’s counter to this is a single, conditional line: when patient don’t respond to treatment, this just means that they are not rigorous in adhering to their treatment. There is no conclusion here; however, we can assume the implicit conclusion is denying the interviewer’s conclusion. Basically, the therapist’s conclusion would be “my claim still holds."
Why is this argument flawed? It’s circular reasoning: he’s repeating a claim the interviewer attributed to him: with rigorous adherence to proper treatment, insomnia is curable. He’s ignoring the evidence that the interviewer puts forth to discredit him and sneakily assuming a causal relationship that isn’t valid.
Two things:
First: when the interviewer says: “Patients suffering from insomnia do not respond to treatment,” he could have been talking about patients who did adhere to the proper treatment rigorously.
Knowing this allows us to understand the possibility of the next point:
Second: the therapist says that if the patients do not respond, it must be because they didn’t adhere rigorously to the treatment. He’s assuming causation when, as we mentioned above, it could be that patients did adhere to the treatment rigorously and there is another reason the treatment was not effective.
There are a couple of flaws here: first, the illicit causal relationship, and second, the circular reasoning. Let’s go into the answer choices, making sure we hit our two-step test: is this answer choice descriptively accurate? Is this the flaw?
Correct Answer Choice (A) Not only is this descriptively accurate, but it represents the issue of assuming causation and circular reasoning. The argument is ignoring evidence that could show that patients were following the treatment rigorously, and asserts his claims as if the disconfirming evidence would not affect the validity of his claims.
Answer Choice (B) This is not descriptively accurate – treatment is used with consistent meaning throughout the stimulus.
Answer Choice (C) This is descriptively accurate, but it is not a flaw. While there could be different causes for different cases of insomnia, this does not mean that the treatment for each needs to be different. This answer choice does not address the issue of why the argument is flawed.
Answer Choice (D) This is descriptively accurate. But it’s not a flaw. The issue at hand has to do with a repetition of beliefs that ignores evidence and implies causation illicitly. Statistical evidence is not a flaw because statistics are not relevant to the kind of flawed support the therapist’s argument contains.
Answer Choice (E) This is descriptively accurate, but it’s not the flaw. Remember, the therapist is only talking about patients who receive and don’t respond to treatment. Everything else is irrelevant to the argument.
This is a sufficient assumption (SA) question because the question stem says: “conclusion is properly drawn if which one of the following is assumed?”
Sufficient assumption questions tend to be very formal. We’re looking for a rule that would validate the conclusion, specifically by bridging the premise and conclusion through the rule. Not only are we extrapolating the rule from our argument, but we’re plugging that rule back into the argument to make it valid. Our rule/prephrase will look like: if [premise], then [conclusion].
Our first sentence looks like a straightforward premise: visits to the hospital by heroin users increased by 25% in the 1980s.
The next sentence provides a hypothesis/conclusion to the phenomenon: the use of heroin rose in the 80s. The argument wants us to believe that if visits to the hospital by heroin users increased, then use increased. Why should I believe that? There could be a ton of other reasons why this would not be true! Maybe the stigma around heroin use decreased, so people were more willing to go in for help but usage is the same. Maybe that year, they started lacing heroin with something that warranted a visit to the hospital but usage didn’t increase. The list goes on!
What we need here is a rule that discounts all of those possibilities, something like “if hospital visits by heroin users are increasing, the use of heroin is increasing.” Now, if we plug this rule back into the stimulus, in a world in which heroin users increasingly go to the hospital, it must also be true that the use of heroin is increasing. We sandwich the premise and conclusion together in a conditional rule, bridging them to help make our argument valid. (Note that we’re not saying one causes the other, we’re just establishing a relationship between the two).
Answer Choice (A) This answer choice doesn’t address our argument. We’re trying to show that with increasing hospital visits, the use of heroin increases. What does seeking medical care at specific stages of heroin use have to do with increased hospital visits during a fixed period of time? This answer choice doesn’t fit into the argument at all.
Answer Choice (B) This interacts with our argument by pointing out that some of the visits have been made by the same person. This could mean that the number of users and the amount of use is the same, just that some people come in more frequently, which weakens our argument.
Correct Answer Choice (C) This establishes the positive correlation between hospital visits by heroin users and the overall use of heroin.
Answer Choice (D) If new methods are less hazardous, this could explain why use has increased. However, if use is safer, why are hospital visits increasing in the first place? Remember, we need to validate our entire argument, not just the conclusion. This is out.
Answer Choice (E) This could interact with the premise portion of our argument if we assume that they increasingly began identifying themselves as heroin users when they come to the hospital in the 80s, but that’s a big stretch since we don’t know if this has always been the case or if it became a norm in the 80s. Even if we can assume this, it still doesn’t help validate our conclusion. In fact, it could weaken it: it’s not that use has increased, it’s that more people are open about their use of heroin.
We know this is a sufficient assumption question because the stem says the “ conclusion...would be properly drawn if which one…was assumed?”
Sufficient assumption questions tend to be very formal. We’re looking for a rule that would validate the conclusion, specifically by bridging the premise and conclusion through the rule. Not only are we extrapolating the rule from our argument, but we’re plugging that rule back into the argument to make it valid. Our rule/prephrase will look like: if [premise], then [conclusion].
The first sentence is describing the features of some languages as they compare to English, specifically with kinship systems, and then makes a conclusion: people of other languages who have different words for different family members (like Hindi speakers or Korean speakers) evidence “a more finely discriminated kinship system” than English speakers do. This argument sounds good. Is the main conclusion of the argument? Let’s read on.
The next sentence goes into another difference between languages: different languages vary in the number of words they have for colors.
Our last sentence starts with “therefore,” which is a conclusion indicator. Not only is this a comparative conclusion, but it’s a very long one. However, we can break it down. Let’s just pretend language X is the language that has fewer words for colors than English. The conclusion is saying that X speakers can’t visually distinguish between as many colors as English speakers can. Before we get into the analysis, is this our main conclusion? Yes! The first two sentences are almost at once context, at once an analogy. The main conclusion is this last sentence.
The analogy they’re making is understandable: uncles are called uncles in English; doesn’t matter if they’re on your mom’s or dad’s side. That’s why we can say speakers “evidence a more finely discriminated system…” The word evidence is important – it’s not like English speakers don’t recognize that “father’s brother” is different from “mother’s brother,” it’s just that other languages have actual words to represent these specific relationships.
With the color argument, it’s a little bit different. It's about our senses. Here, we’re saying X speakers, because of their limited vocabulary on colors, can’t distinguish between, say, royal blue and navy blue. That’s a wild conclusion! What if they can distinguish and describe it, but they just don’t have a word for it? This is the gap between the premise and the conclusion. To mend this gap, we have to connect the premise and conclusion by tying “words” and “the ability to distinguish” specifically relating to our senses. Something like: having different words to describe something (color) is directly related to our senses’ ability to distinguish between things (colors).
Answer Choice (A) How does this fit into the argument? This is going back to the analogy part of the stimulus and adding more information to it. It doesn’t help prove that words are needed to distinguish things.
Correct Answer Choice (B) This wording is convoluted, but if it’s broken down, it makes sense! Each language will have different words for every sensory quality they can distinguish. Here, “sensory quality” includes visualizing all of the different colors. Yes, it’s very broad, but that’s okay - this broadness enables the validity of our argument.
Answer Choice (C) This falls outside of our argument. We don’t really care about categories, we care about how we perceive things within those categories.
Answer Choice (D) This is so close, but the word “categories” here doesn’t apply for the same reason we cited in C. If I swapped it out for “words within categories,’ and then swapped “important” to “needed,” the answer would have been good.
Answer Choice (E) This potentially explains why they don’t have many words for colors. But that doesn’t matter; we’re more interested in the reason why they can’t perceive or distinguish between colors.