Summarize Argument
Criticism by politicians that their opponents’ ideas are incomprehensible is insincere. Incomprehensible political agendas will not be realized because political mobilization requires many people to work with a common purpose. Every politician knows this. This implies that any politician would not actually promote their ideas incomprehensibly, making the criticism insincere.
Identify Conclusion
The conclusion is the author’s claim about criticizing political opponents for incomprehensible messaging: “Such criticism, however, is never sincere.”
A
People who promote political agendas in an incomprehensible manner should be regarded as insincere.
This misrepresents the argument. The criticism is what the political scientist calls insincere, not those who promote agendas incomprehensibly.
B
Sincere critics of the proponents of a political agenda should not focus their criticisms on the manner in which that agenda is promoted.
The author makes no claims about what sincere critics do. Additionally, the author only claims that criticisms about incomprehensibility are insincere. There could be other valid criticisms on the manner of promotion.
C
The ineffectiveness of a confusingly promoted political agenda is a reason for refraining from, rather than engaging in, criticism of those who are promoting it.
The political scientist simply claims that the criticism is insincere. He does not make claims about reasons to refrain or engage in the criticism.
D
A politician criticizing his or her political opponents for presenting their political agendas in an incomprehensible manner is being insincere.
This accurately paraphrases the conclusion. The political scientist says this type of criticism is insincere, therefore a politician who engages in it is being insincere.
E
To mobilize large numbers of people in support of a political agenda, that political agenda must be presented in such a way that it cannot be misunderstood.
This is support for why criticism about incomprehensibility is insincere. Political messaging must necessarily be understandable.
Summarize Argument: Phenomenon-Hypothesis
The argument concludes that organic factors which affect the symptoms of mental illnesses are not evenly distributed around the world. This is based on the claim that symptoms of mental illness that are known to be affected by organic factors vary greatly in different places around the world.
Identify and Describe Flaw
The argument overlooks alternative explanations for the variation of mental illness symptoms, other than uneven distribution of organic factors. Other environmental or systemic causes, like climate, culture, or healthcare, could also affect mental illness symptoms. Differences in these alternative factors could explain the global variation of symptoms.
A
does not say how many different mental illnesses are being discussed
There’s no need to specify how many different mental illnesses are being discussed in order to draw conclusions about the variation of certain symptoms of mental illness.
B
neglects the possibility that nutritional factors that contribute to deficiencies in compounds in the brain vary from culture to culture
This possibility is not neglected by the argument. It’s consistent with the argument’s conclusion that organic factors—such as deficiencies in compounds in the brain—vary across the globe.
C
fails to consider the possibility that cultural factors significantly affect how mental illnesses manifest themselves in symptoms
The argument fails to consider any explanations for the variation of mental illness symptoms around the world, other than uneven distribution of organic factors. Cultural factors that affect the manifestation of mental illness would be one plausible alternative.
D
presumes, without providing justification, that any change in brain chemistry manifests itself as a change in mental condition
The argument simply doesn’t claim that any change in brain chemistry manifests as a change in mental condition.
E
presumes, without providing justification, that mental phenomena are only manifestations of physical phenomena
The argument doesn’t claim that mental phenomena are only manifestations of physical phenomena, just that some mental phenomena (mental illness symptoms) are at least in part affected by certain physical phenomena (organic factors).
Summarize Argument
The politician concludes that privatizing national parks will benefit visitors. She reaches this conclusion by analogy: a privatization project in telecommunications benefited consumers.
Notable Assumptions
By appealing to the privatization of telecommunications, the politician assumes that there are no relevant difference between telecommunications and national parks. She also assumes that there’s some relevant analog to competition among telecommunications providers for national parks.
A
It would not be politically expedient to privatize the national parks even if doing so would, in the long run, improve service and reduce the fees charged to visitors.
It doesn’t matter what would be politically expedient. We care about whether or not it would benefit visitors.
B
The privatization of the telecommunications industry has been problematic in that it has led to significantly increased unemployment and economic instability in that industry.
Even if that’s true, it still benefited consumers. The politician concludes about how privatizing national parks would benefit visitors, so we don’t care about other problems privatization may cause.
C
The vast majority of people visiting the national parks are unaware of proposals to privatize the management of those parks.
We don’t care whether the visitors know the parks might be privatized. We care whether privatization would benefit them.
D
Privatizing the national parks would benefit a much smaller number of consumers to a much smaller extent than did the privatization of the telecommunications industry.
It would still benefit visitors. This agrees with the politician’s conclusion.
E
The privatization of the national parks would produce much less competition between different companies than did the privatization of the telecommunications industry.
Privatizing telecommunications benefitted consumers through increased competition, but that wouldn’t happen with national parks since there’s so little competition in the industry. Thus, the politician’s appeal to a supposedly analogous case isn’t valid.
"Surprising" Phenomenon
Why did people who ate lots of beta-carotene in their food avoid deadly cancer and heart disease when people taking beta-carotene supplements experienced no changes to their health?
Objective
The correct answer must fail to explain why people in the two studies experienced such different health outcomes. Every wrong answer, meanwhile, will state a flaw in the studies’ designs or explain why people who eat foods rich in beta-carotene are less likely to die from cancer and heart disease than those who take a supplement.
A
The human body processes the beta-carotene present in foods much more efficiently than it does beta-carotene supplements.
This would explain the discrepancy. People who eat foods rich in beta-carotene process more of it than those who only take supplements.
B
Beta-carotene must be taken for longer than 12 years to have any cancer-preventive effects.
This would explain why people in the first study showed benefits while people in the second study did not. Those in the second study did not consume high levels of beta-carotene over a long enough period to achieve health benefits.
C
Foods rich in beta-carotene also tend to contain other nutrients that assist in the human body’s absorption of beta-carotene.
This would explain the discrepancy. People who eat foods rich in beta-carotene eat food also rich in other nutrients, and those nutrients cause the lower risk of deadly cancer and heart disease.
D
In the 12-year study, half of the subjects were given beta-carotene supplements and half were given a placebo.
This does not explain the discrepancy. The author states that people who took the supplements experienced no health benefits, regardless of the placebo group.
E
In the 24-year study, the percentage of the subjects who had a high intake of beta-carotene-rich foods who smoked cigarettes was much smaller than the percentage of the subjects with a low intake of beta-carotene-rich foods who smoked.
This would explain the discrepancy. People in the first study were less likely to die of cancer and heart disease because they were less likely to smoke cigarettes.
Summarize Argument
The doctor concludes that bulging or slipped disks, which are often claimed as the causes of serious back pain, could not cause serious back pain. This is based on the observation that a significant number of individuals have bulging or slipped disks, but have never experienced serious back pain.
Identify and Describe Flaw
Because many people have bulging or slipped discs without serious back pain, the doctor concludes that these conditions cannot cause serious back pain. But just because these conditions don’t always cause serious back pain on their own, that doesn’t mean they can’t be among the causative factors of serious back pain.
A
A factor that need not be present in order for a certain effect to arise may nonetheless be sufficient to produce that effect.
The doctor isn’t making any claims about some factor that is sufficient, but not necessary, for an effect. Rather, the argument claims that slipped or bulging disks are not sufficient to cause serious back pain.
B
A factor that is not in itself sufficient to produce a certain effect may nonetheless be partly responsible for that effect in some instances.
The doctor concludes that, since bulging or slipped disks are not sufficient to produce serious back pain, they never cause serious back pain. This ignores that they could still be partly responsible for some instances of serious back pain, and thus still “causes.”
C
An effect that occurs in the absence of a particular phenomenon might not occur when that phenomenon is present.
The doctor doesn’t make any claims about an effect that occurs in the absence of some phenomenon. Rather, the doctor discusses how the phenomenon of a slipped or bulging disk is not always followed by the effect of back pain.
D
A characteristic found in half of a given sample of the population might not occur in half of the entire population.
The doctor’s argument doesn’t rely on applying sample data to the entire population. The fact that half the sample is observed to have slipped or bulging disks without serious back pain is enough to say that these conditions aren’t always sufficient to cause serious back pain.
E
A factor that does not bring about a certain effect may nonetheless be more likely to be present when the effect occurs than when the effect does not occur.
How likely bulging or slipped disks (the factor) are to accompany serious back pain (the effect) isn’t relevant to the argument. The doctor isn’t concerned with how often these two things co-occur, but with their causal relationship.
It is virtually certain that the government contract for building the new highway will be awarded to either Phoenix Contracting or Cartwright Company. I have just learned that the government has decided not to award the contract to Cartwright Company. It is therefore almost inevitable that Phoenix Contracting will be awarded the contract.
Summarize Argument
The author concludes that Phoenix Contracting will almost certainly get the government contract for the new highway. He supports this by noting that the contract was expected to go to either Phoenix Contracting or Cartwright Company, and the government has decided not to award it to Cartwright Company.
Describe Method of Reasoning
The author draws his conclusion that Phoenix Contracting will very likely get the government contract by using the process of elimination. He notes that the contract was likely going to go to either Phoenix Contracting or Cartwright Company. Then, by claiming that Cartwright Company has been ruled out as a possibility, the author concludes that Phoenix Contracting will almost certainly get the contract.
A
concluding that it is extremely likely that an event will occur by ruling out the only probable alternative
The author concludes that it is extremely like that an event (Phoenix Contracting getting the government contract) will occur by ruling out the only probable alternative (Cartwright Company getting the government contract).
B
inferring, from a claim that one of two possible events will occur, that the other event will not occur
Actually, the author infers, from a claim that one event will not occur, that another event will occur. His claim is about an event not occurring, while his conclusion is about an event occurring. (B) reverses these.
C
refuting a claim that a particular event is inevitable by establishing the possibility of an alternative event
The author doesn’t refute a claim that a particular event is inevitable. Rather, he concludes that a particular event is almost inevitable. Also, he eliminates, rather than establishes, the possibility of an alternative event.
D
predicting a future event on the basis of an established pattern of past events
The author does predict a future event, but he does so by ruling out the only probable alternative, not on the basis of an established pattern of events.
E
inferring a claim about the probability of a particular event from a general statistical statement
By concluding that Phoenix Contracting will almost inevitably get the government contract, the author does infer a claim about the probability of a particular event. But he does this by eliminating the only probable alternative, not based on a general statistical statement.