#8 - Grasses and woody plants are planted on dirt embankments to keep the embankments from eroding.

[Administrator]

Complete Question Explanation

Flaw in the Reasoning—Cause and Effect. The correct answer choice is (E).

Answer choice (A):

Answer choice (B):

Answer choice (C):

Answer choice (D):

Answer choice (E): This is the correct answer choice.

This explanation is still in progress. Please post any questions below!

[Mikelsat]

Hi, I chose E because I focused on the conclusion, "Therefore, bringing in predators...", and thought though predators may solve the rodent problem, it does not solve the rotting problem from clippings. However, when looking over the question, I had trouble coming up with a reason to why A is wrong.

[Beatrice Brown]

Hi Mike! Great job on getting the right answer on this one, and that's definitely the right line of reasoning for selecting answer choice (E)

Answer choice (A) explains a different flaw than the one that occurred in the stimulus. As you noted, in the stimulus, the author assumes that eliminating one cause would solve the problem, when there are in fact two causes that both contribute to the problem and would both need to be addressed to prevent the erosion.

Answer choice (A) is discussing a correlation vs. causation flaw. If this flaw occurred, the author would assume that two things that are merely correlated are also causally related to one another. So for example, the author may have made the following claim: "piles of clippings tend to attract more rodents than embankments that do not have these clippings." If this were the premise, then the conclusion would contain a correlation vs. causation flaw because we can't draw a causal conclusion from this statement. However, the stimulus as given doesn't do that because it correctly establishes a causal relationship.

I hope this helps!

[CJ12345:]

Hi, Powerscore,
I still did not figure out the difference between A and E. I thought A is also correct because two events (erosion of the embankments and rodents) do co-occur. The author does try to establish a causal relationship as rodents cause the erosion of the embankments (that's why he suggests eradicating the rodents to prevent erosion). Why is A not right?

[Jeff Wren]

Hi CJ,

For arguments containing causal reasoning, it's always important to distinguish whether the causal reasoning appears in the premises or in the conclusion. Usually the causal flaw comes in the conclusion where the author makes a causal claim that is based only on a correlation or coincidence.

If an argument states a causal claim in a premise, that is accepted as true and not a flaw in-and-of itself.

Here, the argument establishes in the premises that the roots of the woody plants "keep the embankments from eroding." The argument also establishes in the premises that the rodents "damage the woody plants roots." Based on these two facts, the rodents are (at least partly) causing the embankments to erode by damaging the roots that prevent the erosion. In other words, a causal relationship between the rodents and the embankment erosion has been established in the premises and is not simply coincidence.

The flaw in the argument occurs in the conclusion, which assumes that removing one of the causes of the erosion (the rodents) will solve the problem, while ignoring the other stated cause of the erosion (the piles of grass clippings causing the roots to rot). This is best captured in Answer E.