Self-paced
Support Most people believe that yawning is most powerfully triggered by seeing someone else yawn. ████ ██████ █████ ███████ ██ ██████████ ███ ████ ██████ ███ ████ ███ ████ ███████████ ██ ████ █████ ██ ███ █████ ██ ███ █████ ██ ██ ███ ██ ███████ ██████████ ██ ███████ ████████ █████ ██████ ███████ ████ ████ ████ ██ ███ ████ ████████████ █████ ██ ████████
Objective: Identify a Flaw
The author concludes that seeing someone else yawn is the most powerful trigger of yawning. Why? Because most people believe this to be true! According to historians, this was a widespread belief in the past as well.
In this argument, the author supports a factual conclusion with evidence only about popular beliefs. But we have no reason to think that most people are correct—we don't know if it's actually true that seeing someone else yawn is the most powerful trigger of yawning. Because the type of support offered (belief) doesn't match the type of conclusion advanced (fact), the argument is unconvincing; this mismatch is the flaw.
Even having identified the flaw, though, it's not always easy to find the correct answer. Answer choices can be phrased in tricky ways that misdirect our attention. So it's important to read closely and be certain the answer choice completely matches the flaw that we identified. This will help us to avoid trap answers.
17.
The argument is most vulnerable ██ █████ ███ ██ ███ █████████ ███████████
a
It attempts to ███████ ███ ██████████ ██████ ██ █████████ ████ ██████████ ██ █████ ██████
The author is not committing circular reasoning. The conclusion is different from the support: although they look similar, when reading closely we can see that the conclusion is about the factual cause of yawning, whereas the support is about people's beliefs.
To make (A) correct, the support would have to be a factual claim that seeing someone yawn is the strongest trigger of yawning. This would have to replace the author's discussion of popular beliefs.
b
It cites the ████████ ██ ██████████ ██ ███████ ███████ ██ ██████ ███████ ██ █ █████ ████ ████ ███████ █████ ████ ██ ██████████
The author does cite historians of popular culture, but fully within their area of expertise. The claim for which these historians are cited is that in the past, a certain belief about the cause of yawning has been widespread. And we can expect historians of popular culture to be experts about common beliefs—that's what popular culture is.
If the author had cited historians of popular culture to support a scientific claim about the cause of yawning, then (B) could be correct. That kind of claim would truly be outside their area of expertise.
c
It makes a ████████ ██████████████ █████ ███████ █████ ██ ████████ █████ ████ █ ███████ ██████ ██ ████████ ██████
The author doesn't draw evidence from particular cases, so (C) can't be correct. It simply doesn't describe the argument the author makes.
d
It supports its ██████████ ██ █████████ ██████ ██ ███████ ██ █ ██████ ████ ██ ███████ ████████
The author's evidence is entirely about opinion—that currently and in the past, lots of people believed a particular claim about yawning. And the question at hand is factual—the conclusion is about the actual cause of yawning. What's more, this mismatch makes the argument unconvincing. (D) accurately describes the argument's flaw.
e
It takes for ███████ ████ █████ ████ ██ █████ █████ ████ ███ ███ ██ ██████
The author only concludes that seeing someone else yawn is "the most irresistible" cause of yawning. That doesn't exclude the possibility of other causes, meaning (E) does not accurately describe the argument. Yawns could still have other causes; as long as they're lesser causes, that's perfectly consistent with the argument.