ISAT Identifying Assumptions in Arguments 5 — Questions and Answers
Question 1: Argument: 'The fact that ancient peoples built the pyramids with primitive tools proves humans had help from extraterrestrials.' What assumption does this argument depend on?
- Ancient humans lacked knowledge of mathematics and engineering
- The pyramids could not have been built using only human ingenuity and labor with available tools (Correct answer)
- Extraterrestrial beings have visited Earth on multiple occasions
- Modern engineers would not be able to replicate pyramid construction
Correct answer: The pyramids could not have been built using only human ingenuity and labor with available tools
The argument assumes it is impossible for humans to have accomplished this feat alone, making extraterrestrial assistance the only remaining explanation.
Question 2: Argument: 'Because no scientific study has proven that this supplement is harmful, it is safe to take.' What assumption does this make?
- Scientific studies always detect harmful effects when they exist
- Absence of proof of harm is equivalent to proof of safety (Correct answer)
- The supplement has been on the market for many years without incident
- Regulatory agencies have reviewed the supplement's ingredients
Correct answer: Absence of proof of harm is equivalent to proof of safety
The argument treats the lack of evidence of harm as positive evidence of safety, assuming these two things are equivalent.
Question 3: Argument: 'Our team's productivity increased after we switched to four-day work weeks; we should make this change permanent.' What assumption underlies this recommendation?
- Employees prefer shorter work weeks regardless of salary impacts
- The productivity increase will be sustained long-term rather than being a temporary novelty effect (Correct answer)
- Other companies have already adopted four-day work weeks successfully
- The four-day week reduced employee absenteeism
Correct answer: The productivity increase will be sustained long-term rather than being a temporary novelty effect
The argument assumes the early productivity gains reflect a durable change rather than a short-term motivational boost from novelty.
Question 4: Argument: 'Because the two candidates have nearly identical policy platforms, voters should choose based on personality.' What assumption is present?
- Voters are incapable of evaluating policy positions independently
- Policy platform similarity means the candidates' actual governing behavior would also be identical (Correct answer)
- Personality is a stronger predictor of job performance than policy positions
- The candidates deliberately copied each other's platforms
Correct answer: Policy platform similarity means the candidates' actual governing behavior would also be identical
The argument assumes that similar stated positions mean governing outcomes would also be equivalent, making other factors the only meaningful differentiator.
Question 5: Argument: 'This investment advisor has achieved above-average returns for the past five years, so you should trust her with your savings.' What assumption is this based on?
- The advisor charges lower fees than competitors
- Past investment performance is a reliable predictor of future performance (Correct answer)
- Above-average returns indicate superior analytical skills rather than favorable market conditions
- The advisor's clients have not withdrawn their funds during this period
Correct answer: Past investment performance is a reliable predictor of future performance
The argument assumes historical returns will continue, ignoring the well-known principle that past performance does not guarantee future results.
Question 6: Argument: 'People who own dogs live longer on average than people who don't; getting a dog will therefore extend your life.' What assumption is made?
- Dog ownership increases physical activity through daily walks
- Dog ownership itself extends life rather than both being explained by a common factor such as better general health or social connectedness (Correct answer)
- The life-extending benefit is equal across all dog breeds
- Cat ownership does not confer the same longevity benefit
Correct answer: Dog ownership itself extends life rather than both being explained by a common factor such as better general health or social connectedness
The argument assumes the correlation is causal, ignoring that healthier or more socially connected people may be more likely to own dogs.
Question 7: Argument: 'The senator voted against the environmental protection bill, so she clearly does not care about the environment.' What assumption does this argument make?
- Environmental protection bills always reflect the best available scientific evidence
- Voting against a bill means opposing its stated goal, rather than objecting to specific provisions, costs, or methods (Correct answer)
- Senators are required to vote in line with their constituents' preferences
- The environmental protection bill would have passed without the senator's vote
Correct answer: Voting against a bill means opposing its stated goal, rather than objecting to specific provisions, costs, or methods
The argument assumes opposition to the bill equals opposition to its environmental goals, ignoring that one can support an aim while opposing a specific approach.
ISAT Identifying Assumptions in Arguments 5
Argument: 'The fact that ancient peoples built the pyramids with primitive tools proves humans had help from extraterrestrials.' What assumption does this argument depend on?