Summarize Argument
The author concludes that there are no endangered species of ants. Why? Because insects in general are so successful that they spread into virtually every ecosystem, and ants are the most successful insect.
Identify and Describe Flaw
This is the cookie-cutter flaw of confusing part v. whole. The author observes that the biological family of ants is successful, and concludes that every individual ant species must be successful.
But some qualities can be true of a whole without being true of every part, or vice versa. Ants in general could be very successful, but some species of ants could still be endangered.
But some qualities can be true of a whole without being true of every part, or vice versa. Ants in general could be very successful, but some species of ants could still be endangered.
A
the Arctic Circle and Tierra del Fuego do not constitute geographically isolated areas
The author doesn’t presume that either is isolated; they’re used to demonstrate wide geographic range (extreme north vs. extreme south).
B
because ants do not inhabit only a small niche in a geographically isolated area, they are unlike most other insects
The author says that insects are definitely not the kind of animals limited to small niches, so this can’t be the flaw.
C
the only way a class of animal can avoid being threatened is to spread into virtually every ecosystem
This goes beyond what the argument states. The author says that two options for animal species are to go extinct or spread into virtually every ecosystem. He doesn’t indicate that those are the only two options.
D
what is true of the constituent elements of a whole is also true of the whole
This describes the part-to-whole flaw, but this is the reverse of what the author does. Instead, he commits a whole-to-part flaw; he attributes a property true of a whole (ants as a family) to each of its individual parts (individual species of ants).
E
what is true of a whole is also true of its constituent elements
This is the cookie-cutter whole-to-part flaw. The author takes for granted that a property true of a whole (ants as a whole are successful) is also true of the parts making up that whole (every individual ant species is successful). But that's flawed reasoning. Even if ants are generally successful, individual ant species could be endangered.
Summarize Argument: Phenomenon-Hypothesis
The analyst hypothesizes that university administrators tend not to choose university professors who do not pursue research for scientific administration positions. This is based on a phenomenon demonstrated by a recent survey: biology professors who don’t pursue research are underrepresented in scientific administrative positions.
Notable Assumptions
The analyst assumes a causal relationship based on a correlation. Specifically, the analyst assumes that the underrepresentation of professors who do not pursue research in scientific administrative positions is caused by their choice not to engage in research.
A
In universities there are fewer scientific administrative positions than there are nonscientific administrative positions.
This does not affect the argument. Nonscientific administrative positions are not relevant to, and outside the scope of, the argument.
B
Biologists who do research fill a disproportionately low number of scientific administrative positions in universities.
This weakens the argument. It attacks the assumption that the professors’ failure to pursue research leads to their underrepresentation in science admin positions (instead of another factor), which implies that those who pursue research would be better represented in these roles.
C
Biology professors get more than one twentieth of all the science grant money available.
This does not affect the argument. Grant money is not relevant to, and outside the scope of, the argument.
D
Conducting biological research tends to take significantly more time than does teaching biology.
This does not affect the argument. The time it takes to conduct research is not relevant to, and outside the scope of, the argument.
E
Biologists who hold scientific administrative positions in the university tend to hold those positions for a shorter time than do other science professors.
This does not affect the argument. The argument is concerned with one’s likeliness to be appointed to a scientific administration position in the first place. The time biologists spend in these positions is outside the scope of the argument.
Summarize Argument
Catmull concludes that historians never determine what actually happened in the past. Why? Because different historians always arrive at different conclusions when studying the same events.
Identify and Describe Flaw
Catmull claims that, because historians disagree, they never arrive at the truth. The flaw in his reasoning is that some historians may still have arrived at the truth, even if not all of them have. The fact that they disagree shows that not all of them can be right, but it doesn’t show that all of them are wrong.
A
draws a conclusion that simply restates a claim presented in support of that conclusion
This is the cookie-cutter flaw of circular reasoning; it doesn’t apply here. Catmull’s conclusion is an unwarranted leap from his premise, not a restatement of it.
B
concludes, solely on the basis of the claim that different people have reached different conclusions about a topic, that none of these conclusions is true
Catmull assumes that, because historians disagree about the past, none of their conclusions can be true. He overlooks the possibility that some historians may have accurately determined what happened, even without universal agreement.
C
presumes, without providing justification, that unless historians’ conclusions are objectively true, they have no value whatsoever
Catmull likens historians’ conclusions to fiction, but he doesn’t suggest that this means they have no value whatsoever.
D
bases its conclusion on premises that contradict each other
Catmull’s premises don’t contradict either, so this isn’t the flaw.
E
mistakes a necessary condition for the objective truth of historians’ conclusions for a sufficient condition for the objective truth of those conclusions
This is the cookie-cutter flaw of confusing sufficiency and necessity; it isn’t applicable here because Catmull isn’t using conditional logic.
"Surprising" Phenomenon
Why did Muratori win the election if Muratori was significantly behind Kenner in polling conducted in the homes of eligible voters just before the election?
Objective
The right answer will be a hypothesis that addresses something that wasn’t captured by the polling conducted in the homes of eligible voters just before the election. The thing that wasn’t captured could be something that changed after the poll or that the poll didn’t cover.
A
The positions taken by Muratori and Kenner on many election issues were not very similar to each other.
The positions taken by Muratori and Kenner are irrelevant. We know Kenner was significantly ahead of Muratori in polling conducted in the homes of eligible voters right before the election, so we need an answer that addresses why the election results didn’t follow this polling.
B
Kenner had held elected office for many years before the recent election.
Kenner holding elected office in the years before the election tells us nothing about why the polling conducted immediately before the election wasn’t representative of the election results.
C
In the year leading up to the election, Kenner was implicated in a series of political scandals.
Even with Kenner being implicated in scandals in the year leading up to the election, Kenner was ahead in polling immediately before the election. We need to know why that polling didn’t reflect the election outcome.
D
Six months before the recent election, the voting age was lowered by three years.
The polling mentioned in the stimulus occurred immediately before the election and covered eligible voters, so voters made eligible six months before the election would’ve been considered by the polling. The polling accounts for (D).
E
In the poll, supporters of Muratori were more likely than others to describe the election as important.
If (E) is true, Kenner’s supporters were less likely to consider the election important and thus probably less likely to vote. The poll in the stimulus showing Kenner had more supporters than Muratori doesn’t capture this, which could lead to the poll being inaccurate.
Summarize Argument
The author concludes that it’s unlikely an education party is viable in the long run. This is based on the following:
Historically, in order to be viable in the long run, a party needs at least 30% of eligible voters prepared to support it by joining it or by donating money to it.
According to a recent poll, only 26% of eligible voters are prepared to join an education party, and only 16% of eligible voters are prepared to donate money to one.
Identify and Describe Flaw
The author overlooks the possibility that the combination of people who are prepared to join and people who are prepared to donate would exceed 30%. In other words, the author takes for granted that the set of people who are prepared to donate is completely contained within the set who are prepared to join. But this doesn’t have to be true. Some people might want to donate without wanting to join.
A
some of those who said they were willing to donate money to an education party might not actually do so if such a party were formed
If even fewer people donate than expected, that doesn’t undermine the argument. If anything, that suggests the level of support for an education party is even lower.
B
an education party could possibly be viable with a smaller base than is customarily needed
The author noted that an education party is “unlikely” to be viable. This recognizes that it’s possible some education parties might be able to gain viability even if they don’t meet the requirements observed based on the historical evidence.
C
the 16 percent of eligible voters prepared to donate money to an education party might donate almost as much money as a party would ordinarily expect to get if 30 percent of eligible voters contributed
The overall amount of money donated is irrelevant to the author’s reasoning, because the historical evidence relied on is about % of voters who are prepared to join or donate. The historical requirement for viability isn’t about the amount of money that a party needs.
D
a party needs the appropriate support of at least 30 percent of eligible voters in order to be viable and more than half of all eligible voters support the idea of an education party
The author considers this. The author acknowledges that over 50% support the idea of an education party, but states that historically there are specific kinds of support required (join/donate). That’s why the author thinks the “over 50% support” isn’t enough for viability.
E
some of the eligible voters who would donate money to an education party might not be prepared to join such a party
If some of the voters who would donate are not those who would join, that shows it’s possible the combination of voters who would join plus the voters who would donate could exceed 30%. This is why the premises don’t show that an education party is likely to fail.
Reza: Language requires the use of verbal signs for objects as well as for feelings. Many animals can vocally express hunger, but only humans can ask for an egg or an apple by naming it. And using verbal signs for objects requires the ability to distinguish these objects from other objects, which in turn requires conceptual thought.
Summary
The stimulus can be diagrammed as follows:
Notable Valid Inferences
Conceptual thought is a necessary condition for language use.
Animals do not have language.
A
Conceptual thought is required for language.
This must be true. As shown in the diagram, by chaining the conditional claims, we see that conceptual thought is a necessary condition for language.
B
Conceptual thought requires the use of verbal signs for objects.
This could be false. (B) says “Conceptual thought → Use of verbal signs for objects.” In our diagram, we only have conceptual thought as a necessary condition; we don’t know what conceptual thought is a sufficient condition for.
C
It is not possible to think conceptually about feelings.
This could be false. We have no information about which topics are possible to think about conceptually.
D
All humans are capable of conceptual thought.
This could be false. In our diagram, “human” is a necessary condition for “use of verbal signs for objects.” We are not given “humans” as a sufficient condition for anything, so we don’t know anything that “all humans” can do.
E
The vocal expressions of animals other than humans do not require conceptual thought.
This could be false. We know that many animals can vocally express at least one feeling (hunger). It could be the case that vocal expression of hunger requires conceptual thought; our stimulus just doesn’t address this.