Summarize Argument
The author concludes that lowering cholesterol reduces heart disease risk. She supports this with a study showing that people treated with pravastatin, which lowers cholesterol, had fewer heart attacks and heart disease deaths than people not taking the drug. She also notes that people with heart disease often have higher cholesterol levels.
Identify and Describe Flaw
This is the cookie-cutter flaw of mistaking correlation for causation. The author shows that high cholesterol and heart disease are correlated and assumes that high cholesterol causes heart disease risk.
Also, she thinks that pravastatin further proves this causation, assuming that it reduces the risk of heart disease by lowering cholesterol. But the drug could reduce heart disease risk in another way, and simply lower cholesterol as a side effect.
A
neglects the possibility that pravastatin may have severe side effects
Pravastatin may have severe side effects, but this wouldn’t affect whether it reduces the risk of heart disease by lowering cholesterol.
B
fails to consider that pravastatin may reduce the risk of heart disease but not as a consequence of its lowering cholesterol levels
The author assumes that pravastatin reduces the risk of heart disease by lowering cholesterol. She uses this as evidence that lowering cholesterol reduces heart disease risk. But the drug could reduce the risk in another way, with cholesterol reduction just being a side effect.
C
relies on past findings, rather than drawing its principal conclusion from the data found in the specific study cited
The author does use past findings about the link between high cholesterol and heart disease. But she also uses the data found in the specific study on pravastatin.
D
draws a conclusion regarding the effects of lowering cholesterol levels on heart disease, when in fact the conclusion should focus on the relation between pravastatin and cholesterol levels
The author does draw a conclusion regarding the effects of lowering cholesterol on heart disease, but this isn’t a flaw in her argument. Just because the study on pravastatin was used as evidence doesn’t mean that her conclusion has to be about pravastatin.
E
fails to consider what percentage of the general population might be taking pravastatin
It doesn’t matter what percentage of the general population take pravastatin. We know that enough people take it to make up a sizable study on its effects, which is all that matters here.
Summarize Argument: Phenomenon-Hypothesis
The archaeologist concludes the first Eurasian settlers in North America were not the closest. Why? Because a projectile found in a mastodon is dissimilar from any in the closest part of Eurasia, and the first Eurasians in North America settled shortly before the North American mastodon went extinct.
Notable Assumptions
The archaeologist assumes the projectile could not have been made by people from the closest part of Eurasia, either because it resembles a projectile from elsewhere in Eurasia or because people from the closest part of Eurasia were less likely to develop a new projectile for some other reason. She also assumes that only the first settlers to North America from Eurasia could have made the projectile, and that it penetrated the mastodon while it was alive.
A
The projectile found in the mastodon does not resemble any that were used in Eurasia before or during the Ice Age.
This eliminates the distinction between the closest part of Eurasia and the rest of Eurasia. If the projectile doesn’t resemble any from Eurasia, there’s no reason to assume its makers came from farther in Eurasia.
B
The people who occupied the Eurasian area closest to North America remained nomadic throughout the Ice Age.
This doesn’t mean those people left the area closest to North America. It’s possible people in Eurasia maintained well-defined geographic boundaries despite living nomadic lifestyles.
C
The skeleton of a bear from the same place and time as the mastodon skeleton contains a similar projectile.
The species of prey is not relevant to the argument. The subsequent extinction of the mastodon implies the settlers who killed it were some of the early settlers, and the existence of a bear with the same projectile doesn’t change that fact.
D
Other North American artifacts from the peak of the Ice Age are similar to ones from the same time found in more distant parts of Eurasia.
This provides another reason to believe the archaeologist’s conclusion, but does not address her argument. The presence of these other artifacts does not challenge any assumption made by the archaeologist to draw her conclusion.
E
Climatic conditions in North America just before the Ice Age were more conducive to human habitation than were those in the part of Eurasia closest to North America at that time.
This draws no distinction between the parts of Eurasia closer to and farther from North America that calls into question the archaeologist’s conclusion. It’s possible the parts of Eurasia farther from North America were equally inhospitable.
Philosopher: Scientists talk about the pursuit of truth, but, like most people, they are self-interested. Accordingly, the professional activities of most scientists are directed toward personal career enhancement, and only incidentally toward the pursuit of truth. Hence, the activities of the scientific community are largely directed toward enhancing the status of that community as a whole, and only incidentally toward the pursuit of truth.
Summarize Argument
The philosopher concludes that the scientific community’s activities are mainly about enhancing the community’s status, and only incidentally about pursuing truth. She supports this by saying that scientists are self-interested and most scientists’ professional activities are mainly about enhancing their personal careers, and only incidentally about pursuing truth.
Identify and Describe Flaw
This is a cookie-cutter “part to whole” flaw, where the author takes a characteristic of one part or parts of a group and assumes it to be true of the group as a whole.
The philosopher takes a premise about most scientists— that they’re motivated by career-enhancement rather than truth— and uses it to draw a conclusion about the scientific community as a whole— that it too is motivated by status-enhancement rather than truth.
A
improperly infers that each and every scientist has a certain characteristic from the premise that most scientists have that characteristic
The philosopher does draw an improper inference from the premise that most scientists have a certain characteristic. But that inference is about the scientific community as a whole, not about “each and every scientist.”
B
improperly draws an inference about the scientific community as a whole from a premise about individual scientists
The philosopher improperly infers that the scientific community as a whole is motivated by status-enhancement rather than truth from a premise stating that most individual scientists are motivated by these things.
C
presumes, without giving justification, that the aim of personal career enhancement never advances the pursuit of truth
The author never assumes this. In fact, she allows for the possibility that the aim of career enhancement can advance the pursuit of truth by saying that scientific activities are directed “only incidentally toward the pursuit of truth.” She just claims that truth isn’t the goal.
D
illicitly takes advantage of an ambiguity in the meaning of “self-interested”
The author simply doesn’t make this mistake because she uses the term “self-interested” clearly in her premise about most scientists.
E
improperly draws an inference about a cause from premises about its effects
The philosopher doesn’t use causal reasoning in her argument; she never argues that one thing causes another. So (E) can’t describe her flaw.
Summarize Argument
The politician concludes that nations should tax income only at rates lower than 30 percent in order to maintain their value system and way of life. For support, he cites a general rule: a high income tax produces a negative incentive for innovation, which causes a country to fall behind in the arms race. This causes those nations to lose international power, a circumstance threatening their values and way of life.
Notable Assumptions
The politician makes many assumptions. He assumes an income tax bracket exceeding 30 percent is high enough to produce a negative incentive for innovation, that such an incentive always hampers innovation, that falling behind in the arms race means suffering a “strategically disadvantageous position,” and that a nation that loses power internationally is at risk of compromising its way of life and values.
A
The top level of taxation must reach 45 percent before taxation begins to deter inventors and industrialists from introducing new technologies and industries.
This disputes the assumption that any income tax bracket exceeding 30 percent is high enough to create a negative incentive for technological innovation.
B
Making a great deal of money is an insignificant factor in driving technological innovation.
This calls into question the general rule, critical to the politician’s argument, that a high income tax produces a negative incentive for innovation.
C
Falling behind in the international arms race does not necessarily lead to a strategically less advantageous position.
This refutes the assumption that nations who lag in the arms race must be strategically disadvantaged, and thus breaks a link in the politician’s chain of reasoning.
D
Those nations that lose influence in the world community do not necessarily suffer from a threat to their value system or way of life.
This disputes the assumption that nations that lose international power risk compromising their values or way of life, breaking a link in the politician’s chain of reasoning.
E
Allowing one’s country to lose its technological edge, especially as concerns weaponry, would be foolish rather than merely a historical accident.
This is consistent with the politician’s statements because he says that falling behind in the arms race will cause a country to lose its international power, even if it’s due to foolishness.
Summarize Argument: Counter-Position
The geneticist concludes that the “horror-movie image” of human cloning producing an army of duplicates for wealthy people is an unrealistic fear. To support this, she says that the long-term process of raising and educating clones would mean that adults produced by cloning would not have identical goals, outlook, or personality, so an “army of exact duplicates” could not be produced. Then, the geneticist raises another, more realistic, outcome: using clones as living “organ banks.”
Identify Argument Part
The claim in the question stem gives a reason that the fear of cloning producing an army of duplicates is an unrealistic fear.
A
It is a reason for dismissing the various fears raised by ethicists regarding the cloning of human beings.
The claim in the question stem is targeted specifically toward the fear of using cloning to create an army of duplicates, not the “various fears” of ethicists. Further, the argument does not dismiss “various fears,” just one specific fear.
B
It is evidence that genetic clones will never be produced successfully.
The argument does not claim that genetic duplicates will never be produced successfully; it just says that an army of exact duplicates is an unrealistic fear due to differences in outlook, personality, or goals.
C
It illustrates the claim that only wealthy people would be able to have genetic duplicates made of themselves.
The argument does not claim that only wealthy people would have this ability; rather, the argument just raises the possibility that wealthy people would do so.
D
It is evidence for the claim that wealthy people might use genetic duplicates of themselves as sources of compatible organs for transplantation.
The claim in the question stem is used to reject one possible fear, not as evidence to support another potential risk of human cloning.
E
It is a reason for discounting one possible fear concerning the cloning of human beings.
The claim in the question stem is a premise that supports the conclusion, which is that one possible fear of human cloning is unrealistic. The referenced text gives a reason to discount one possible fear, so this is the correct answer.