PrepTest 113

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Flawed Parallel Reasoning

Stimulus Summary:
Study - Give people fruits/vegetables, some of which had pesticides
Results - Eating fruits/vegetables can decrease risk of some cancers
Additional conclusion - Pesticides don't have health risks

Answer Anticipation:
There are two issues with this argument—one of which knowing a common pattern in this content helps; the other of which breaking it down into its parts helps.

First, the content-based one. When arguments conclude something about overall health, they frequently base this on premises that talk about a subset of overall health. Here, the study discussed the incidence of some cancers, but it concludes something about health risks overall. While cancer is a health risk, there are many others, and showing that pesticides aren't associated with increased cancer risks doesn't show that they don't have health implications—maybe they contribute to heart disease or neurological issues. In jumping from a subset of health risks to the overall category, this argument is flawed.

Second, let's break the argument down into its parts. We have a study, along with the results of that study. The author goes beyond those results, though, showing that a distinction not made by the study suggests that a similar conclusion can be drawn about a subset of the supposed causes. Here, that means that there were pesticides on some of the fruits/vegetables, and yet the reduced incidence of cancer was still seen, so pesticides must not contribute to cancer (well, health risks, but we already addressed that gap).

However, that assumes that those who ate pesticide-laden fruits/veggies had the same reduction as others. If the non-pesticide-eating group saw a 20% decline in cancer, but the other group had a 5% decline, the pesticides aren't looking so good. Or, alternatively, if everyone had some fruits/veggies with pesticides on them, then we don't know if the decreased incidence of cancer would have been even lower without that.

So we need to find an answer that has both of these flaws—the jump from a subset (cancer) to overall (health), and a failed distinction in a study leading to a conclusion that it can't justify because we don't know how the results are split up.

Answer Explanation:
This answer jumps from research/premises about "major illnesses" to a conclusion about "health risk," making the same jump as the stimulus did. It also doesn't analyze the relative level of decrease among the different communities, so the second flaw is present, as well, making this the correct answer.

Key Takeaway:
There are some content-based patterns on the exam that can really help us tackle questions efficiently. One such pattern is present here—arguments that draw a conclusion about overall health usually do so based on a discussion of a subset of health, making them flawed.

Incorrect. This answer has the reverse shift as in the stimulus—the research/premise is about overall health, and the conclusion is about a subset. This reversal is enough to let us rule this answer out.

Incorrect. This answer arguably makes the same shift from a subset of risk in the premise (getting into an accident) to overall risk in the conclusion (which might include risk of death once in an accident). However, it shifts between driving a motorcycle with extensive training and driving a car without it, which are two different things—unlike the stimulus, which was always talking about eating fruits/veggies.

Incorrect. This answer goes from the presence of microbes to the risk of contracting microbial illness—not a jump from a subset to a larger category.

Incorrect. This answer goes from a premise about long-term health benefits to a conclusion about long-term health risks—that's not a jump from a subset to a category, so we can rule this out.