Summarize Argument: Counter-Position
The commissioner concludes that critics are incorrect to claim that a decision about a power plant was premature. Why? Because the decision was based on a neighborhood association report, which the commissioner is certain contains accurate information (even though the commissioner hasn’t read it closely). Also, the commissioner agreed with a previous recommendation from this association about a different issue.
Identify and Describe Flaw
The commissioner concludes that a decision was not premature, even though it was based on a single report which the commissioner hadn’t studied closely. This is supported only by a baseless assurance that the report is accurate, and a favorable view of a previous report on a different issue.
The overarching flaw is that the commissioner relies too much on a single, unverified report by an organization of unknown reliability.
A
It takes for granted that the association’s information is not distorted by bias.
The commissioner accepts the association’s report as the only necessary basis for a decision, but offers no assurance that the association is not biased.
B
It draws a conclusion about the recommendations of the association from incomplete recollections.
The commissioner does not appear to have an incomplete recollection of the association’s recommendation. Also, the conclusion is about whether the decision was hasty, not about the recommendation itself.
C
It takes for granted that the association’s report is the only direct evidence that needed to be considered.
The commissioner uses the association’s report as the only basis for a decision, without ever mentioning the possibility of considering other evidence or explaining why other evidence is not necessary.
D
It hastily concludes that the association’s report is accurate, without having studied it in detail.
The commissioner claims to be “sure” that the report is accurate, but admits to having not studied it in detail. However, without having studied the report in detail, the commissioner cannot really be sure of its accuracy.
E
It takes for granted that agreeing with the association’s past recommendation helps to justify agreeing with its current recommendation.
The commissioner uses an agreement with a past report to defend the use of the association’s current recommendation as the only basis for a decision. However, the past report does not guarantee the quality of the present recommendation.
Summarize Argument: Phenomenon-Hypothesis
The author concludes that eating less fat will help reduce cancer risk. He supports this by pointing to a correlation between cancer rates and fat intake: countries with higher cancer rates also have higher average fat intake.
Notable Assumptions
Based on a mere correlation, the author hypothesizes that higher fat intake is what’s causing the higher cancer rates. This means he assumes that the relationship isn’t the reverse (i.e., the higher cancer rates aren’t somehow causing higher fat intake), and also that there isn’t some hidden, alternative cause that’s actually responsible for the difference in cancer rates between different countries.
A
The differences in average fat intake between countries are often due to the varying makeup of traditional diets.
In order for this to weaken the argument, traditional diets would need to provide an alternative explanation for the difference in cancer rates between different countries. However, the possible effect of any given traditional diet on cancer rates is entirely unclear.
B
The countries with a high average fat intake tend to be among the wealthiest in the world.
In order for this to weaken the argument, the wealth of a country would need to provide an alternative explanation for the increased cancer rates in high-fat counties. However, the connection between increased national wealth and increased cancer likelihood is entirely unclear.
C
Cancer is a prominent cause of death in countries with a low average fat intake.
The stimulus tells us that cancer nevertheless occurs more commonly in countries with higher average fat intake. (C) fails to address any reason for that difference in cancer rates, and so fails to weaken the conclusion that the difference is due to fat intake.
D
The countries with high average fat intake are also the countries with the highest levels of environmental pollution.
This provides an alternative cause for the difference in cancer rates between different countries: it’s not fat intake that’s responsible, but rather exposure to pollution.
E
An individual resident of a country whose population has a high average fat intake may have a diet with a low fat intake.
The fact remains that, in general, high average fat intake correlates with high cancer rates. The possibility that someone’s fat intake might deviate from the average has no effect on the argument.
Don't worry if you didn't get this exceptionally difficult question correct. Later lessons in Advanced Logic will help to elucidate the concepts behind this question.
To see why (E) is incorrect, first recall what the practice in the stimulus was in a general form. Stated broadly, it was the practice of having people set standards from which they themselves would later benefit. This is why having executives sit on boards to determine salaries of other executives is not a great idea. This is also why having doctors sit on juries to determine damages for malpractice suits for other doctors is not a great idea. Whatever standard they set would later be used for them.
Now how does (E) do any of that? Sure you have a group of people. And there's something something money. That's it. Each person in the group is directly evaluating each other, confidentially but who cares. There's a set amount of money, say $100, to be given to the group consisting of say 5 people. Who gets how much? Well, that depends on how each person is evaluated by their peers. So... I guess if I'm in the group, I'm incentivized to give everyone else a low rating so that I could get more of the $100 pie? I guess. Wait but what am I even doing. I'm supposed to be setting a financial standard that would later benefit me. That's not what I'm doing at all. I'm just directly screwing my co-workers over so that I benefit.
A
When webs of many different species of spider were illuminated with a uniform source of white light containing an ultraviolet component, many of these webs did not reflect the ultraviolet light.
Irrelevant. The author never said that Glomosus spiderwebs are the only spiderwebs that reflect ultraviolet light.
B
When the silks of spiders that spin silk only for lining burrows and covering eggs were illuminated with white light containing an ultraviolet component, the silks of these spiders reflected ultraviolet light.
Like (A), this is irrelevant. We don’t care about other spiderwebs that reflect ultraviolet light.
C
When webs of the comparatively recently evolved common garden spider were illuminated with white light containing an ultraviolet component, only certain portions of these webs reflected ultraviolet light.
Irrelevant. We don’t care about other spiderwebs that reflect ultraviolet light.
D
When Drosophila fruit flies were placed before a Glomosus web and a synthetic web of similar pattern that also reflected ultraviolet light and both webs were illuminated with white light containing an ultraviolet component, many of the fruit flies flew to the Glomosus web.
The author argues that the specific patterns of ultraviolet light attract insects. This suggests something else about the Glomosus spiderwebs is actually what attracts them.
E
When Drosophila fruit flies were placed before two Glomosus webs, one illuminated with white light containing an ultraviolet component and one illuminated with white light without an ultraviolet component, the majority flew to the ultraviolet reflecting web.
Between the otherwise identical Glomosus spiderwebs, insects chose the one with ultraviolet reflections. This strengthens the idea that ultraviolet reflections, and not something else about the spiderwebs, are what attract insects.