This is a Strengthen question.
The argument begins with a phenomenon that a certain ancient society burned large areas of land. Naturally, we wonder why they did this. The author presents other people's hypothesis: they burned large areas of land to prepare the ground for planting, which means that the ancient society was beginning the transition to agriculture.
To test this hypothesis, we can check its predictions. One prediction would be evidence of agriculture. If it's true that they burned the ground in preparation for planting, then we should expect to find evidence of agriculture. But we have little evidence of cultivation after the fires. This strongly implies that the other people's hypothesis of transition to agriculture is wrong. And so the author concludes it is likely that the society was still a hunter-gatherer society.
Now, one quick assumption you might've noticed is whether ancient societies fall into the binary buckets of either agricultural or hunter-gatherer. That is something to keep in mind, but as it turns out, those two buckets do largely capture all societies. The answer choices don't try to undercut that assumption.
But don't forget that we still have this phenomenon presented in the beginning argument. The author hasn't given an explanation of why the ancient society burned large areas of land. She has only, rather effectively, disposed of a bad explanation.
This is where Correct Answer Choice (D) improves the reasoning of the argument. It says hunter-gatherer societies are known to have used fire to move animal populations from one area to another. This presents a plausible explanation of the phenomenon unexplained in the original argument. If this is true, then that phenomenon itself becomes support for the author's conclusion that the society was still a hunter-gatherer society.
Answer Choice (A) says many ancient cultures had agriculture before they began using fire to clear large tracts of land. This means that fire clearing of land is not necessary for the transition to agriculture. That's good to know if you were curious about early human civilization. But this has nothing to do with the argument. The fact is the particular ancient society we’re talking about did clear large areas of land with fire. We’re trying to figure out what that means about the status of their civilizational development.
Answer Choice (B) says hunter-gatherer societies use fire for cooking and for heat during cold weather. This doesn't affect the argument at all. The argument told us that this particular society used fire to burn large areas of land and then we try to argue that this particular society was still a hunter-gatherer society. Information about hunter-gatherer societies using fire to do other things doesn't help the claim.
Answer Choice (C) says many plants and trees have inedible seeds that are contained in hard shells and are released only when subjected to the heat of a great fire. This is probably the most attractive wrong answer choice because it also looks like it's trying to provide an explanation for the phenomenon described above. It's trying to suggest that the reason why the ancient society burned large areas of land was to extract the seeds from the hard shells. There are at least two problems with (C), however. The first problem is that the seeds are inedible. That means you can't eat them. So what are you trying to do by extracting them? One plausible explanation is that you're trying to plant them. But that's not good for this argument, because that suggests that the culture might have been agrarian. The other problem is that this explanation doesn't fit very well with the phenomenon. Even if it's true that the seeds are released only when subjected to the heat of a great fire, it's not clear that the way to extract a seed is to burn down an entire tract of land. Why not collect all the shells and just burn them? Wouldn’t that be easier than setting a whole forest on fire? Notice (D) doesn't suffer from this problem. The hypothesis fits the facts. If you're trying to move entire populations of animals, then burning large areas of land makes sense. The solution is at the right scale for the problem.
Answer Choice (E) says few early societies were aware that burning organic material can help create nutrients for soil. This suggests the preclusion of a potential explanation. Before reading (E), one potential explanation for why the ancient society burned large areas of land was to fertilize the soil. After reading (E), it seems less likely that that's what our ancient society was attempting to do. What is the significance of this? I suppose it's less likely now that our ancient society was agrarian. But this was already established in the argument.
This is a Weaken question.
The ethicist begins her argument with a general rule: hospital staff must not deceive patients about their medical treatment. Then she talks about a specific case. Dr. Faris told a patient that medication A would help him sleep even though medication A has no known sleep-inducing properties. The ethicist then concludes that Dr. Faris has violated the rule.
She does concede the point that after taking medication A, the patient's sleep did in fact improve. That's a concession point because it doesn't help her argument.
This argument should remind you of PSA questions because those are the questions where we most frequently encounter general rules applied to specific cases. And if you were to treat this as a PSA question, where would you supply the missing assumption bridge? It has to be a bridge linking Dr. Faris's actions to deceiving the patient. If Dr. Faris's actions constitute deception, then he did violate the rule. Otherwise, he didn't.
So do they constitute deception? That depends on whether he knew medication A would help the patient sleep. If he knew it would, then he wasn’t trying to deceive the patient, he was just trying to be a doctor. If he knew it wouldn't, then he was trying to deceive the patient. The ethicist assumes that he knew it wouldn’t because medication A has no known sleep-inducing properties.
But, as the ethicist concedes, medication A did in fact help the patient sleep. So was that just a coincidence or is there something else going on? Is it possible for a medication with no known sleep-inducing properties to nonetheless help a patient sleep?
Correct Answer Choice (C) tells us that indeed it is possible. It says that medication A is a pain reliever that can indirectly lead to sleep due to a reduction in the patient's discomfort. This is a crucial clarification of the causal relationship between medication A and sleep. It respects what the premises said about medication A, that it has no known sleep-inducing properties. That's true. It doesn't directly cause sleep. But it indirectly causes sleep by reducing pain, which reduces discomfort, which facilitates sleep. Given what (C) reveals about medication A, the ethicist's argument falls apart. It seems far less likely now that Dr. Faris deceived his patient with the claim that medication A would help him sleep. Rather, it seems far more plausible that Dr. Faris knew that reducing pain would facilitate sleep.
Given what you know about the placebo effect, can you imagine a different formulation of (C) such that it would still be correct? It could go something like this: sleep, like pain reduction, is highly susceptible to the placebo effect and nearly all patients who are told that they are receiving a substance that would help them sleep will experience improved sleep regardless of whether that substance itself induces sleep. This answer would be very similar to the actual answer (C) because a placebo effect is simply one kind of indirect causal chain. The administration of the placebo causes internal chemical reactions in the body that cause sleep.
Answer Choice (A) says Dr. Faris was aware that medication A had no known sleep-inducing properties. This would strengthen the argument. The reason is because of an implicit requirement of the rule. Deception is an intentional act. An intent to deceive requires factual knowledge about the medication’s lack of sleep-inducing properties. But as we already discussed above, (A) wouldn’t strengthen the argument by much since it’s still possible that Dr. Faris knew that medication A would only indirectly help the patient sleep. So while (A) might be a correct answer for a Necessary Assumption question, it wouldn't be the correct answer choice for a PSA question.
Answer Choice (B) says a committee at the hospital is currently considering revisions to the hospital's ethics code. Who cares? (B) may as well have told us that the committee is considering what they're going to order for lunch. The ethics code is what it is regardless of what the committee is considering. We just have to answer the question of whether Dr. Faris violated the code as it currently is. That answer does not depend on what the committee ultimately decides to do with the code.
Answer Choice (D) says several other members of the hospital staff prescribed medication A to patients who have trouble sleeping. This answer is reminiscent of many wrong answers in RRE questions. There, a recurring type of wrong answer is one that piles on additional phenomena in need of an explanation, rather than supplying the explanation. Do you see how this is similar? Our concern coming into the answers was whether Dr. Faris is in violation of the ethics code for having prescribed medication A. (D) doesn't answer that question. (D) just adds to the problem. Now I'm wondering whether these other members of the hospital staff are also in violation of the ethics code.
I suspect (D) might be baiting us to assume that if a sufficient number of people do a thing, then that thing isn’t wrong. But that’s a terrible assumption.
Answer Choice (E) says Dr. Faris knew that the patient was not taking any other medication that has sleep-inducing properties. This is irrelevant because the argument never assumed anything about Dr. Faris's knowledge of whether the patient was already taking, say, melatonin or Ambien. The argument does assume that Dr. Faris knew that medication A has no known sleep-inducing properties, as we discussed in (A), and that Dr. Faris knew that medication A also wouldn't indirectly facilitate sleep. If those two assumptions can be established, then it does look like Dr. Faris has violated this specific ethics code.
A
Dr. Faris was aware that medication A had no known sleep-inducing properties.
B
A committee at the hospital is currently considering revisions to the hospital’s ethics code.
C
Medication A is a pain reliever that can indirectly lead to sleep due to a reduction in the patient’s discomfort.
D
Several other members of the hospital staff prescribed medication A to patients who had trouble sleeping.
E
Dr. Faris knew that the patient was not taking any other medications that have sleep-inducing properties.
This is an RRE question.
The stimulus tells us that according to a new study, after a heavy rainfall, pollution levels in Crystal Bay reach their highest levels. We also learn that rainwater is almost totally pure. Together these constitute the phenomenon we are trying to explain. The stimulus also tries to generate a feeling of surprise or puzzlement by telling us what we should expect. That is, we should expect the pure rainwater to dilute the polluted seawater.
As with all RRE questions, whether or not we feel like the phenomenon is puzzling largely depends on what assumptions we were making. If we assume that the stimulus paints the whole picture, in other words, the phenomenon is merely as simple as that which the stimulus describes, then we might think this is surprising. On the other hand, if you are a subject matter expert, say someone who studies urban pollution, you probably already know that there are other factors at play. You probably already know the explanation for the phenomenon.
We don't need to be subject matter experts to get RRE questions right. We just need to keep an open mind about possible explanations.
Correct Answer Choice (B) says most of the rainwater that eventually reaches Crystal Bay falls on pesticide-treated fields before being carried into the bay. This is a specific version of what I described generally above. The story is indeed more complicated. While it's true that some rain falls directly into the bay and would have the effect of diluting the pollution in the bay, as it turns out, most rain doesn't fall directly into the bay. Rather, it falls onto land and then runs off into the bay, picking up and carrying whatever it is that it comes into contact with. This answer choice specifically tells us that it picks up and carries pesticides into the bay. We only need to assume that pesticides are a type of pollution.
Answer Choice (A) says compared to the total amount of polluted seawater in Crystal Bay, the amount of rainwater that falls into it is negligible. This answer choice might have worked had the phenomenon been different. If the phenomenon merely said that after a heavy rainfall, pollution levels remain unchanged in Crystal Bay, then perhaps this answer provides an explanation. Yes, it's true that rainwater is pure, which would dilute polluted seawater. But in order for the dilution to be measurable, there needs to be some minimum threshold amount of rainwater. For example, if you simply pour a bucket of rainwater into the bay, nobody would expect the pollution to be diluted because a bucket of rainwater is a negligible amount. That's what this answer choice provides. The explanation is that there just simply isn't enough rainwater. Fair enough, but the phenomenon above that we are trying to explain isn't that pollution remains unchanged after rainfall. Rather, it's that pollution reaches its highest levels after heavy rainfall. This answer does not explain that at all.
Answer Choice (C) says most rainwater carried by clouds consists of water that's evaporated from oceans around the world. This is irrelevant. C tells us the origins of rainwater. It treats rainwater as an effect and reveals to us rainwater's causes. We simply don't care about that. We already know rainwater is pure, and that sets up the expectation of diluting pollution in Crystal Bay. We’re simply trying to explain why that expectation was upset.
Answer Choice (D) says the single leading cause of pollution in Crystal Bay is beachgoers leaving behind trash which blows into the bay. In order for this answer to explain the phenomenon, we have to assume that heavy rainfall somehow causes more trash either to be left behind or to be blown into the bay. We might be tempted to say that rainfall tends to be accompanied by strong winds which would blow more trash and debris into the bay. Fair enough, but it still remains to be explained why the rainfall itself, which is mostly pure water, doesn't counteract the extra pollution from the trash by diluting the existing pollution in the bay. Contrast this answer with Answer Choice (B). There, we have no such lingering question. We are told there that most rainwater that reaches the bay carries pollution, which means that it's only a minority of rainwater that reaches the bay in its pure form.
Answer Choice (E) says other nearby ocean areas experience a pattern of pollutant increase and decrease that is extremely similar to that of Crystal Bay. This is a cookie-cutter wrong answer for RRE questions. This answer reveals a phenomenon consistent with the phenomenon in the stimulus and is also in need of an explanation just like the phenomenon in the stimulus. So rather than solving the problem, this answer only adds to the problem.
A
Compared to the total amount of polluted seawater, the amount of rainwater that falls into Crystal Bay is negligible.
B
Most of the rainwater that eventually reaches Crystal Bay falls on pesticide-treated fields before being carried into the bay.
C
Most rainwater carried by clouds consists of water that has evaporated from oceans around the world.
D
The single leading cause of pollution in Crystal Bay is beachgoers’ leaving behind their trash and debris, which then blows into the bay.
E
Other nearby ocean areas experience a pattern of pollutant increase and decrease that is extremely similar to that of Crystal Bay.
This is a Weaken question.
The stimulus starts by telling us that domesticated animals were created by the breeding of only the sufficiently tame wild animals. In other words, it's just a subset of the wild animals that were amenable to breeding for domestication. As an example, the argument uses dogs and wolves. It says that after a number of generations of breeding only the wolves that are sufficiently tame, we create dogs. That’s it for the premises. They’ve established how domestication occurs and provided an example of domesticating wolves to create dogs.
Now we get the conclusion. It says all animals can in principle be bred for domesticity. This conclusion is very weakly supported. The logic of this argument is that of generalization, which is a special kind of argument by analogy. The reasoning assumes that wolves are representative of all wild animals in terms of their potential tameness. More broadly, the argument assumes that just because some animals can be domesticated, all animals can be domesticated. Whether or not this is a reasonable assumption simply depends on the state of the world. If it's true that all animals contain some members that are sufficiently tame, like wolves, then this is a fine assumption. Otherwise, it's not.
Correct Answer Choice (C) reveals that the world is not one in which all animals contain some members that are sufficiently tame. It says that in some animal species, no members ever displayed tameness. That contradicts the core assumption of the argument and therefore weakens the argument.
Answer Choice (A) says domesticated animals cannot be turned into wild species by breeding only those animals that display some wild characteristics. This answer is talking about changing animals in the other direction, from domesticated to wild. It tells us that we can't select for the wildest dogs and breed them with each other and expect to get wolves as a result. That's good to know, I guess, but it has nothing to do with the argument.
Answer Choice (B) says in some animal species, wild members mate more frequently than tame members. So, for example, wolves that are wilder mate more frequently than wolves that are tamer. That is irrelevant to the argument, because domestication involves humans breeding the tame members of wolves. As long as those wolves breed at all, we’re good. We don't care whether they breed more or less than wilder members of their species.
Answer Choice (D) says in some animal species, tame members are less fertile than wild members. Just like (B), we don't care about the comparative fertility of tame to wild. As long as tame members are fertile at all, domestication can occur.
Answer Choice (E) says in some domesticated animal species, some members are much more tame than other members. This is obvious because you wouldn't expect dogs or cats, for example, to be all equally tame. Of course some dogs are going to be more tame than others, and of course some cats are going to be more wild than others. Tameness is on a spectrum. It's not a binary characteristic. But so what? The argument never assumed that members of a domesticated species were all equally tame.
A
Domesticated animals cannot be turned into wild species by breeding only those animals that display some wild characteristics.
B
In some animal species, wild members mate more frequently than tame members.
C
In some animal species, no members ever display tameness.
D
In some animal species, tame members are less fertile than wild members.
E
In some domesticated animal species, some members are much more tame than other members.
This is an RRE Except question.
The stimulus describes a phenomenon and four out of the five answers contribute to an explanation. The stimulus starts by defining two psychological profiles. Repressors are people who repress upsetting thoughts and feelings from conscious awareness. Sensitizers are people who are especially attuned to internal states that freely express distress. Now the stimulus gets to the phenomenon. Repressors tend to be less shy and anxious, can better tolerate frustration, and have superior social skills, better grades, and a greater sense of self-esteem compared to sensitizers.
This stimulus didn't bother to prime our expectations. It didn't tell us anything that might invite us to form expectations that the stimulus upsets. So in that sense, it’s different from many RRE questions that do try to present the phenomenon as surprising. But, in any case, whether or not you find a given phenomenon surprising depends more on what assumption we make.
Here, we know four out of the five answers will provide or contribute to an explanation. So we should dive right into the answers.
Answer Choice (A) says repressors are better able than sensitizers to focus on their work and to avoid distractions. This contributes to an explanation of the phenomenon. This gives us a causal mechanism that explains why repressors have better grades, can better tolerate frustration, and perhaps why they have a greater sense of self-esteem: because they can better focus on their work and avoid distractions.
Answer Choice (B) says repressors are less apt than sensitizers to alienate people by expressing their emotions. This contributes to an explanation of the phenomenon. This gives us a causal mechanism that explains why repressors have superior social skills: by simply refraining from expressing emotions that alienate people.
Answer Choice (C) says parents and other caregivers tend to reward repressors more than they reward sensitizers for academic performance and social behavior deemed desirable. This contributes to an explanation of the phenomenon. This gives us a causal mechanism as long as we assume that external reward from parents and other caregivers incentivizes academic performance and pro-social behavior.
Answer Choice (E) says sensitizers tend to focus more than repressors do on the difficulties of succeeding in their projects rather than on factors that are likely to contribute to success. This contributes to an explanation of the phenomenon. This states a causal mechanism that explains the differential grades and the differential sense of self-esteem. Repressors are focused on the right factors, factors that are likely to contribute to their success, whereas sensitizers are focused on the wrong factors.
Correct Answer Choice (D) does not contribute to an explanation of the phenomenon. One way (D) stands out is that its content is nested within the phrase “some psychologists have hypothesized that…” That means we don't know if the nested clause is true. We only know that it's true that some psychologists have hypothesized whatever is in the nested clause. That's a huge disadvantage that (D) suffers in relation to the other answers. At minimum, (D) requires an additional assumption that the other answers don't, that these psychologists are correct in their hypothesis.
But this is not the only weakness in (D). Even if we edit this answer choice to strip it of its nesting clause, it still wouldn't provide an explanation. The edited version of (D) would say that the desire to maintain social and academic success and self-esteem strengthens repressors’ tendency to repress upsetting thoughts and feelings. This might serve as an explanation for why repressors repress upsetting thoughts and feelings in the first place: because they want to maintain success and self-esteem. But we weren't asked to explain why repressors repress. We were asked to explain why repressors enjoy certain advantages academically, psychologically, and socially that sensitizers don't enjoy. This edited version of (D) does not contribute to an explanation.
A
Repressors are better able than sensitizers to focus on their work and to avoid distractions.
B
Repressors are less apt than sensitizers to alienate people by expressing their emotions.
C
Parents and other caregivers tend to reward repressors more than they reward sensitizers for academic performance and social behavior deemed desirable.
D
Some psychologists have hypothesized that the desire to maintain social and academic success and self-esteem strengthens repressors’ tendency to repress upsetting thoughts and feelings.
E
Sensitizers tend to focus more than repressors do on the difficulties of succeeding in their projects rather than on factors that are likely to contribute to success.
This is a Weaken question.
The stimulus starts with other people's position. A geologist claimed to have discovered in clay a previously unknown form of life called nanobes, which is only 1/10 the size of the smallest known bacteria. With the use of the word “however,” the author signals a transition away from context to argument. The author disagrees with the geologist. She says nanobes are probably not living things but rather inanimate artifacts of the clay’s microscopic structure. That's her conclusion. But why should we believe it? Her premises follow from the word “because.” There are two premises here. The first one is that a reproductive mechanism is a prerequisite for life. She's setting herself up to make the contrapositive argument. You already know that her conclusion is that nanobes probably are not life so you can anticipate that she will try to fail the prerequisite or the necessary condition for life. And indeed she says a nanobe is too small to contain a reproductive mechanism.
And therein lies the crucial assumption of this argument. Has she successfully failed the necessary condition? That depends on whether a nanobe being too small to contain a reproductive mechanism amounts to nanobes not having a reproductive mechanism. The argument assumes so. But if it's possible for a nanobe to be too small to contain a reproductive mechanism yet still somehow have access to or possess a reproductive mechanism anyway, then her argument falls apart.
This is what Correct Answer Choice (B) tells us. It cuts against that assumption. It says single-cell creatures can combine to form a multicelled structure and then reproduce before they disband into separate single cells again. This answer suggests that there may be a crucial distinction between a single nanobe versus a group of nanobes. The premises establish that a single nanobe is too small to contain a reproductive mechanism. But that doesn't imply a group of nanobes do not contain a reproductive mechanism, as the conclusion assumes. Even if you believe that the argument validly establishes that a single nanobe is not alive, again, that doesn't imply a group of nanobes are not alive. This is an instance where an individual member may lack a certain characteristic (a reproductive mechanism or life) yet the group may possess that characteristic.
You might object that we don't know if (B)'s description of single-cell creatures' ability to reproduce has any bearing on nanobes. As it turns out, bacteria are single-celled creatures and so we are at the right scale. But even if you didn't know that, (B) still effectively weakens the argument. This is because weakening the argument is a lower bar than proving that nanobes have a reproductive mechanism. If we wanted to prove the latter, then we would have to assume that (B) applies to nanobes, in other words, that nanobes do in fact come together to reproduce and then separate. But we are not trying to do that. We're just trying to show that the assumption the author made may be false. What was that assumption again? That an organism being too small to contain a reproductive mechanism means it has no reproductive mechanism. (B) falsifies that assumption by revealing the possibility that even if a single nanobe is too small to contain a reproductive mechanism, a group of nanobes could possess a reproductive mechanism. And that is all we need to weaken the argument.
Answer Choice (A) says no known form of bacteria is complicated enough in structure to engage in sexual reproduction. Okay, so that means all bacteria that we know of engage in asexual reproduction. Where’s the fun in that? Also, what are we supposed to do with this information? This has no bearing on the argument. We’re just trying to figure out whether nanobes failed a necessary requirement of life.
Answer Choice (C) says some scientists claim there are fossilized remains of bacteria in meteorites from Mars which are approximately the same size as nanobes. Okay, so something came from Mars and it’s about the same size as nanobes. Some scientists think that that thing is bacteria. Are they right or wrong? If they are wrong, then this is useless information. We actually don't know what the thing is. If they are right, that means it is possible for organisms from Mars as small as nanobes to reproduce. That would directly challenge the conclusion without engaging the reasoning. That’s not how we weaken arguments. Rarely, the Question Stem instructs us to directly go after a conclusion but this one says “weaken.”
Answer Choice (D) says previous definitions of life were based on research done with inferior microscopes no longer in use. That's an interesting historical fact. But are we supposed to presume that the argument above used a previous definition of life, one that was based on shitty microscopes? That seems completely arbitrary and frankly unfair to the argument.
Answer Choice (E) says animals such as cold-blooded lizards can be physiologically simpler though still larger than other animals. (E) is inviting us to analogize lizards to bacteria. It's trying to tell us that just like how bacteria are larger than nanobes, lizards are larger than other animals. And it's suggesting that even though lizards are larger, they are still physiologically simpler, and therefore even though bacteria are larger than nanobes, bacteria are physiologically simpler. That means nanobes are physiologically more complex. You don't need me to tell you how disanalogous this is. Second, even if we concede this analogy, all we can show is that nanobes are physiologically more complex than bacteria. That doesn't solve the problem of whether or not they have reproductive mechanisms. That’s what we needed to resolve.