Argument Evaluation

Consider the following argument:

City Council Member: Our city's public transit system is currently operating at a significant financial deficit. To eliminate this deficit, the transit authority has proposed a 20 percent increase in all bus and subway fares. However, our studies indicate that this fare increase will cause a 25 percent drop in total ridership as commuters switch to other modes of transportation. Therefore, implementing the fare increase will actually worsen the transit system's financial deficit rather than eliminate it.

The argument above necessarily assumes that the transit system's operating costs will not decrease sufficiently to offset the lost revenue when ridership drops by 25 percent.

Sociologist: During the late twentieth century, time-saving domestic technologies, such as automated dishwashers, were widely adopted by households. Paradoxically, surveys from that era indicate that adults in these households reported feeling significantly more pressed for time than adults had in preceding decades. It must be the case that the time saved by these technologies was quickly absorbed by new professional and social obligations, leaving these individuals with less actual free time than people previously possessed.

Which one of the following is an assumption on which the sociologist's argument depends?

Consider the following argument:

The management of the City Tribune newspaper wants to increase the publication's overall profit margin. To achieve this, they plan to switch from their current high-quality printing paper to a significantly cheaper, lower-quality paper. By reducing these production costs, the management concludes that the newspaper's overall profit margin will undoubtedly increase.

Statement: For the management's conclusion to be logically drawn, the argument necessarily assumes that switching to the lower-quality paper will not cause a decrease in readership and sales severe enough to cancel out the financial savings gained from using the cheaper paper.

Architect: We should construct the new civic center using engineered mass timber instead of traditional concrete and steel. Engineered timber is just as structurally sound as concrete and steel, but it has a significantly lower lifecycle carbon footprint. Therefore, by using engineered timber rather than concrete and steel, the city will reduce the overall environmental impact of the civic center's construction.

Which one of the following is an assumption on which the architect's argument depends?

Financial theorist: A financial market is robust only if it is capable of withstanding severe liquidity shocks and maintains transparent trading protocols. The novel commodities exchange, Aetherion, utilizes decentralized anonymous ledgers. Because this feature completely precludes the maintenance of transparent trading protocols, it follows that Aetherion's underlying economic model must be inherently unstable.

Which one of the following is an assumption that, if true, allows the financial theorist's conclusion to be properly drawn?

Public Health Official: Critics of our recent influenza vaccine campaign argue that the vaccine is ineffective. They point out that this year, the absolute number of vaccinated individuals who contracted influenza was 15 percent greater than the number of unvaccinated individuals who contracted the disease. However, these critics fail to recognize that due to our aggressive outreach efforts over the past year, the total number of vaccinated individuals in our district has tripled. Therefore, contrary to the critics' claims, the vaccine has indeed effectively reduced an individual's likelihood of contracting influenza compared to remaining unvaccinated.

Which of the following most accurately describes a flaw in the public health official's reasoning?

Evolutionary Biologist: Fossils of the ancient mammal *Thalassocnus* reveal unusually dense, heavy bones. Some researchers contend this extreme density evolved as a defensive adaptation against blunt-force impacts from terrestrial predators. However, maintaining such bones requires an immense caloric intake rarely justified by defensive needs alone. Because dense bones drastically decrease buoyancy—a vital advantage for foraging aquatic plants in turbulent coastal waters—this skeletal density likely evolved primarily to facilitate underwater grazing rather than as a defense mechanism.

Which one of the following, if true, provides the strongest additional support for the evolutionary biologist's argument?

Below are four distinct logical arguments (Left) and four pieces of evidence (Right). Match each argument to the single piece of evidence that most directly strengthens its conclusion by addressing its specific logical gap.

Archaeologist: The iron artifacts recently excavated at the Qadan burial site contain trace amounts of vanadium. Vanadium is absent from the iron ores of Anatolia, which historians have long considered the sole region possessing iron-smelting technology during that era. However, vanadium is abundant in the raw iron ores found near the Qadan site. Consequently, these artifacts must have been manufactured locally by the Qadan people rather than acquired through long-distance trade.

Which of the following is an assumption on which the archaeologist's argument depends?

Marine biologist: The newly discovered deep-sea sponge Cladorhiza ventis inhabits waters near hydrothermal vents. Unlike most deep-sea sponges, C. ventis entirely lacks the internal canal systems and pores required for filter-feeding on suspended organic matter. Furthermore, the surrounding water is nearly devoid of the zooplankton that carnivorous sponges typically prey upon. Consequently, it is highly likely that C. ventis relies exclusively on symbiotic chemosynthetic bacteria for its nutritional needs.

Which of the following statements, if true, would strengthen the marine biologist's conclusion? (Select all that apply)

The Vendean people, who inhabit a harsh, densely forested mountain region, have a language containing over fifty distinct words for different types of moss. In contrast, neighboring lowland groups have only three such words. A linguist argues that this linguistic disparity exists because the Vendeans' specific environment forced them to develop a highly specialized moss vocabulary for survival, as they utilize various mosses for crucial medicinal and dietary purposes.

Which of the following, if true, provides the most support for the linguist's argument?

Paleontologist: Some researchers conclude that *Drakosuchus*, a large Late Cretaceous crocodilian, was a fully marine reptile because its fossils were discovered in deep-ocean sedimentary deposits alongside marine fossils. However, *Drakosuchus* must have actually been a freshwater predator whose remains were swept out to sea after death. This is because the *Drakosuchus* bones exhibit severe surface pitting, a specific chemical degradation pattern known to occur when the bones of freshwater reptiles are exposed to high-salinity water for extended periods post-mortem.

The paleontologist's argument relies on which one of the following assumptions?

Researchers compared musicians who frequently improvise to those who exclusively play written music, finding that the improvisers have significantly greater neural density in the prefrontal cortex, a region associated with rapid decision-making. The researchers concluded that engaging in musical improvisation causes structural brain changes that enhance decision-making skills. Consequently, educational policymakers argue that incorporating improvisation into school music programs will improve students' ability to make rapid decisions in novel situations.

Which of the following, if true, most strengthens the educational policymakers' argument?

Conservationist: To prevent the local extinction of the endangered Karner blue butterfly, we must introduce controlled burns in the Pine Barrens to restore their natural open-canopy habitat. While critics warn that these fires will initially destroy some Karner blue larvae, the species relies exclusively on wild lupine for oviposition, and wild lupine seeds require fire-induced clearing to germinate and thrive. Thus, initiating a regimen of controlled burns will ultimately ensure a larger, more stable population of Karner blue butterflies in the Pine Barrens.

Which of the following are necessary assumptions on which the conservationist's argument depends? (Select all that apply)

Entomologist: The Corvid butterfly population in the Aral Valley has plummeted over the last decade. Concurrently, there has been a sharp increase in the invasive thread-wasp, a predator of Corvid caterpillars. Nevertheless, the butterfly's decline is almost certainly due to a newly introduced agricultural herbicide, not the wasp. The herbicide, while directly harmless to the insects, accumulates in the soil and severely stunts the milkweed plants that Corvid caterpillars rely on exclusively for food.

Which one of the following, if true, most strengthens the entomologist's argument?

Historian: Any sustained intellectual renaissance relies on a foundation of rigorous dialectical debate, since without such debate it is impossible for a society to avoid stagnating into ideological conformity. The recently analyzed Archonian epoch is universally celebrated by scholars for its vibrant philosophical treatises and its complete lack of ideological conformity. Therefore, it is demonstrably true that the Archonian epoch experienced a sustained intellectual renaissance.

Which of the following most accurately describes a flaw in the historian's reasoning?

To investigate the effects of the amino acid taurine, researchers placed laboratory mice on a diet completely devoid of it, adding the synthetic filler Zylotol to maintain identical caloric intake. These mice soon exhibited severe cognitive decline compared to a control group on a standard diet. The researchers concluded that taurine deficiency directly causes cognitive impairment. A critic countered that Zylotol’s mild neurotoxic properties actually caused the observed decline. Nevertheless, the researchers maintained their original conclusion.

Which of the following, if true, most strongly supports the researchers' original conclusion in light of the critic's objection?

Policy Analyst: In an effort to reduce the municipality's overall greenhouse gas emissions, the local government recently shifted all non-essential administrative staff to a four-day workweek, closing their respective office buildings completely on Fridays. Since this scheduling change took effect, metered energy consumption in these municipal facilities has decreased by exactly one-fifth on Fridays compared to the historical average. Therefore, this policy will inevitably yield a net reduction in the municipality's total greenhouse gas emissions.

Which of the following are assumptions on which the policy analyst's argument depends? (Select all that apply.)

Read the argument below. Apply the Variance Test to evaluate the argument by matching the possible factual discoveries (left) to their logical impact on the agricultural economist's core conclusion (right).

Agricultural Economist: To combat declining yields of the traditional Zea corn crop, valley farmers are being encouraged to switch to a genetically modified variant, Zea-Max. Zea-Max is highly resistant to the region's most common pests, which routinely destroy a large portion of the harvest. Since pest damage is currently the primary cause of crop loss in the valley, adopting Zea-Max will undoubtedly lead to a significant increase in the farmers' overall annual profits.

To alleviate severe traffic congestion, the metropolitan government of Meridia implemented a 'congestion charge'—a substantial toll levied on any vehicle entering the central business district during designated peak commuting hours. One year after the policy's implementation, the total volume of vehicles entering the district during these peak hours had decreased by 25 percent. City officials declared the policy a resounding success. However, critics point out that during the same year, a severe national economic downturn caused a 25 percent drop in office employment within Meridia's central business district. The critics argue that the economic downturn, not the congestion charge, was responsible for the traffic reduction. The city officials reject this criticism, maintaining that the congestion charge was indeed the primary driver of the decreased peak-hour traffic.

Which of the following, if true, provides the strongest support for the city officials' position?