Assumptions

Marine Biologist: The rapid proliferation of the spiny sea urchin is devastating our region's kelp forests. To prevent the complete loss of these forests, conservationists plan to introduce the sunflower sea star, a natural predator of the urchin. Because the sunflower sea star actively hunts these urchins and does not consume kelp, this introduction will successfully halt the destruction of the kelp forests.

Statement: The marine biologist's argument logically depends on the assumption that introducing the sunflower sea star will eliminate the spiny sea urchin population entirely.

Epidemiologist: Our study found that residents of County X who regularly consumed dietary supplements were 30% less likely to develop sleep disorders than those who did not. However, the supplement consumers also reported exercising significantly more on average. Since regular exercise is known to improve sleep quality, we conclude that the supplements themselves likely provide no real protection against sleep disorders.

Evaluate the following statement:
The epidemiologist's argument necessarily assumes that the dietary supplements consumed in County X do not contain ingredients that completely counteract the sleep-enhancing benefits of regular exercise.

Sociologist: A functioning democracy requires its electorate to have access to impartial political reporting. Over the last decade, however, the media landscape has been entirely consolidated by three massive entertainment conglomerates. Because these conglomerates are legally bound to prioritize maximizing their quarterly profits above all other objectives, the fundamental prerequisites for a functioning democracy are presently being undermined.

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

Match each logical argument on the left with the necessary supporter assumption on the right that correctly bridges the gap between its premise and its conclusion.

Environmentalist: Two years ago, the city implemented a ban on the use of artificial fertilizers in all residential gardens to improve the water quality of the adjacent Lake Azure. Recently, tests showed that the concentration of toxic algae in Lake Azure, which feeds on synthetic nitrogen, has decreased by 40%. Therefore, the city's ban successfully achieved its intended goal.

Which of the following must be assumed in order for the environmentalist's conclusion to be properly drawn? (Select all that apply)

Transportation Planner: Any infrastructure project that expands highway capacity inevitably encourages urban sprawl. The newly approved North Corridor expansion will add two additional lanes to the existing highway. Therefore, the North Corridor expansion will undoubtedly result in increased carbon emissions for the region.

Which of the following are assumptions upon which the transportation planner's argument depends? Select all that apply.

Music Historian: The oldest surviving specimens of the Torathi lute feature a soundbox carved entirely from the heartwood of the Veldt oak. Shaping Veldt oak heartwood requires high-carbon steel chisels, which historical records indicate were not available in the Torathi region until the fifth century. Therefore, the Torathi lute must have been invented no earlier than the fifth century.

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

Philosopher: An individual can be held morally blameworthy for an outcome only if the actions leading to that outcome were the product of conscious deliberation. Neurological studies demonstrate that the physical movements involved in routine driving are initiated by the brain milliseconds before the driver becomes consciously aware of the intention to perform them. Therefore, drivers cannot be held morally blameworthy for traffic accidents caused by their physical movements during routine driving.

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

Anthropologist: The recent excavation of sophisticated bone tools at the Marak cave site, located in a soil stratum dating back 80,000 years, challenges the accepted timeline of human cognitive development. Because shaping these tools requires the ability to conceptualize a multi-step manufacturing process, humans must have developed advanced abstract reasoning abilities much earlier than the widely accepted 50,000-year mark.

Statement: The anthropologist's argument necessarily assumes that the bone tools were not introduced into the 80,000-year-old soil stratum by human populations living at a significantly later date.

Sociologist: In a recent study of tech companies, organizations that adopted a decentralized management structure reported a significantly lower rate of employee turnover than those with a traditional hierarchical structure. Therefore, granting employees more autonomy over their daily workflow leads to greater job satisfaction, which in turn encourages them to remain with their company.

Determine whether the following statement is true or false: A necessary assumption of the sociologist's argument is that adopting a decentralized management structure actually results in employees having greater autonomy over their daily workflow.

Match each logical stimulus argument (left) with the specific supporter assumption (right) required to bridge the logical gap between its premise and conclusion.

City Engineer: The newly implemented smart-grid electrical system dynamically routes power based on neighborhood-level real-time consumption data. By doing so, the system effectively minimizes the occurrence of localized power surges during peak usage hours. Therefore, the implementation of this smart-grid system will undoubtedly extend the average lifespan of household appliances across the city.

The city engineer's argument relies on assuming which one of the following?

City official: We are planning to replace our current fleet of diesel public buses with electric buses to reduce the city's overall carbon footprint. Although manufacturing electric buses generates more carbon emissions than manufacturing diesel buses, electric buses produce zero emissions while operating. Therefore, completing this fleet replacement will successfully reduce our overall carbon footprint.

Which of the following statements are necessary assumptions required by the city official's argument? Select all that apply.

Ornithologist: The endangered Kakapo bird relies almost entirely on the fruit of the Rimu tree for breeding. In fact, Kakapos only attempt to breed during years when the Rimu tree produces a massive abundance of fruit, an event known as "mast seeding." Climate models predict that rising average temperatures will cause Rimu trees to mast seed every two years over the next century, rather than their historical average of once every five years. Therefore, the frequency of Kakapo breeding seasons will significantly increase over the next century.

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

Policy Analyst: To combat congestion, the city of Oakhaven recently implemented a $10 toll for private vehicles entering the downtown business district during morning rush hour. Last month, which was the first month of the toll, the number of private vehicles entering the district during morning rush hour dropped by 30% compared to the previous month. Therefore, the financial cost of the toll must be what deterred these drivers from entering the district during morning rush hour.

Which of the following are necessary assumptions required by the policy analyst's argument?

Nutritional Biochemist: The recently synthesized compound 'Z-Sweet' binds perfectly to the tongue's sweet-taste receptors but is entirely indigestible by human metabolic enzymes. Furthermore, longitudinal studies confirm that ingesting Z-Sweet fails to trigger the release of pancreatic insulin. Consequently, substituting dietary sugar with Z-Sweet will guarantee a reduction in overall body adiposity while permanently eliminating neurochemical sugar addiction.

Based on the biochemist's reasoning, which of the following statements act as required supporter assumptions that logically bridge gaps in the argument? Select all that apply.

Art conservator: Traditional chemical solvents used to clean Renaissance oil paintings often seep through the protective varnish and interact directly with the underlying paint pigments. A new cleaning technique, thermal plasma descaling, exclusively removes the outer layer of grime without penetrating the varnish at all. Thus, museums can be assured that employing thermal plasma descaling will never alter the original color balance of these Renaissance paintings.

The art conservator's argument depends on which one of the following assumptions?

Consider the following argument:

Tech Analyst: Working in the office clearly makes InnovateCorp's employees more productive than working remotely. After all, the company's overall productivity increased by 15% last year, which is the exact same year they abandoned their fully remote policy and mandated that all employees work from the office four days a week.

Statement: To logically draw this conclusion, the analyst must assume that InnovateCorp did not also deploy a highly efficient new workflow software last year that drastically reduced the time required to complete routine tasks.

Sociologist: Only societies that possess a formalized system of property rights are capable of developing a complex market economy. Nomadic cultures inherently lack a formalized system of property rights, as their traditional lifestyle prevents them from claiming permanent ownership of specific land tracts. Therefore, it is impossible for nomadic cultures to cultivate highly specialized artisan classes.

The sociologist's argument relies on assuming which one of the following?

Historian: Any society that maintains a standing professional army must divert a substantial portion of its agricultural surplus to the state. However, diverting a substantial portion of agricultural surplus to the state inevitably suppresses the development of an independent merchant class. Therefore, if an ancient society featured a flourishing independent merchant class, it must not have possessed heavily fortified urban centers.

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