PrepTest 108, Section 3, Question 4
The average 40-year-old North American will have watched(27 more words not shown)
The conclusion above follows logically(8 more words not shown)
- AThe habits of(10 more words not shown)
- BAnything people are(11 more words not shown)
- CIt is impossible(6 more words not shown)
- DSome people find(10 more words not shown)
- ECertain forms of(12 more words not shown)
Reading the argument
A million commercials is a lot of exposure. It still isn't the same thing as a demonstrated change in how people think.
The figure is an average, so we shouldn't picture every person watching exactly a million ads. Someone who watches television all day could see many more; someone who rarely watches could see far fewer. Let's accept the average and focus on what the author does with it.
The conclusion sounds plausible to me. Repeated advertising may well influence people. But plausibility isn't the missing evidence. The premise tells us about the amount watched, while the conclusion tells us about an effect on thought. What if people see all those ads without changing their habits of thought?
What we’re looking for
We're asked to supply an assumption that makes the conclusion follow. Then we need a rule connecting a great deal of exposure with an influence on thought. If exposure on that scale guarantees the influence, the missing step is filled.
Working the answers
- A
External influences could matter greatly without television commercials being among the influences that matter. Perhaps people's habits are shaped by books, schooling, and conversations. A doesn't connect the commercial exposure in this argument to the claimed effect. We still need to know that these advertisements influence thought.
- BCorrect
Anything people encounter in great quantity will influence their habits of thought. A million commercials supplies the great quantity; B supplies the resulting influence. Together, they connect the premise to the conclusion.
This rule is broader than the particular case. It covers repeated exposure to other things as well as commercials. That's fine for this task: a broad rule can still prove the specific conclusion when the case falls within it.
- C
Even unavoidable commercials might fail to influence habits of thought. This answer would make exposure harder to escape, but the premise already gives us extensive exposure. We need to establish its effect. Inability to avoid or ignore something does not by itself establish the particular change the author claims.
- D
Think of people who watch a major sporting event partly for the advertisements. Finding those ads interesting tells us about their viewing preferences. It doesn't establish that the commercials influence their habits of thought. An interesting experience and the claimed influence are not automatically the same thing.
- E
Some forms of communication affect thought, but which ones? They could be books or conversations without including television commercials. E is compatible with the commercials having no effect at all.
If commercials have influenced thought, then of course some form of communication has done so. But knowing that some form has an effect doesn't prove that commercials do. We need an assumption that proves this conclusion, and B supplies it.
More Sufficient Assumption questions
- Logical Reasoning Drill Set 10, Question 1Sufficient Assumption
- Logical Reasoning Drill Set 12, Question 4Sufficient Assumption
- Logical Reasoning Drill Set 13, Question 1Sufficient Assumption
- Logical Reasoning Drill Set 3, Question 7Sufficient Assumption
- Logical Reasoning Drill Set 4, Question 7Sufficient Assumption
Learn the LSAT our way
Our platform drills Sufficient Assumption questions at your level and adjusts as you improve.