- PowerScore Staff
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- Joined: Feb 02, 2011
- Wed Mar 30, 2016 6:46 pm
#22670
Question #4: Must Be True, #%. The correct answer choice is (D)
For the first time in this section we’re presented not with an argument, but with a fact set: (1) spleen size is generally a good indicator of bird health, with smaller spleens indicating sickliness; (2) on the whole, birds killed by predators tend to have substantially smaller spleens than birds “killed accidentally” (whatever that may mean).
The obvious conclusion to draw from this then is that birds killed by predators tend to be less healthy than birds killed accidentally.
Note my use of the phrase “tend to be,” which intentionally parallels the author’s toned-down “generally” and “in general.” This type of language softening is vital to recognize in LR stimuli, as it constrains the nature/strength of the correct answer. In short, you can only prove ideas to a degree of certainty allowed by their supporting information, so premises caged in mere likelihood cannot be used to determine anything with certainty.
Answer choice (A): is far too strong. Remember, this is about what is typical, or what generally occurs. Saying that healthy birds are never killed by predators goes well beyond the supporting information in this stimulus.
Answer choice (B): Be careful with the initial language: we don’t know that the majority of small-spleened birds are killed by predators, but rather that of those birds killed spleen size tends to be smaller. It could still be a tiny fraction of the overall total of birds with small spleens that are killed (that is, the vast majority may escape predation).
Answer choice (C): This answer presents entirely new information, requiring a rather large assumption on the part of a test taker. Sickness may play a role in predation rates (in fact it seems to), but that doesn’t support the claim that predators can “sense” sickness.
Answer choice (D): This is the correct answer choice. Once again, our prediction serves us well. Birds with smaller spleens tend to be sicklier than other birds, and birds with smaller spleens tend to be killed by predators more often than are other birds. Conclusion? Sickly birds are more likely than healthy birds to be killed by predators.
Pay particular attention to the language used, with the phrase “more likely than” mirroring the nature of the language in the stimulus (“generally”).
Answer choice (E): Attempting to determine causality from the relationship described is a mistake, since we can’t know the cause behind either the reduced spleen size or poor health. It could be that a smaller spleen causes sickness, or it could be that sickness causes a smaller spleen, or it could be a third element that causes both the smaller spleen and the sickliness.
For the first time in this section we’re presented not with an argument, but with a fact set: (1) spleen size is generally a good indicator of bird health, with smaller spleens indicating sickliness; (2) on the whole, birds killed by predators tend to have substantially smaller spleens than birds “killed accidentally” (whatever that may mean).
The obvious conclusion to draw from this then is that birds killed by predators tend to be less healthy than birds killed accidentally.
Note my use of the phrase “tend to be,” which intentionally parallels the author’s toned-down “generally” and “in general.” This type of language softening is vital to recognize in LR stimuli, as it constrains the nature/strength of the correct answer. In short, you can only prove ideas to a degree of certainty allowed by their supporting information, so premises caged in mere likelihood cannot be used to determine anything with certainty.
Answer choice (A): is far too strong. Remember, this is about what is typical, or what generally occurs. Saying that healthy birds are never killed by predators goes well beyond the supporting information in this stimulus.
Answer choice (B): Be careful with the initial language: we don’t know that the majority of small-spleened birds are killed by predators, but rather that of those birds killed spleen size tends to be smaller. It could still be a tiny fraction of the overall total of birds with small spleens that are killed (that is, the vast majority may escape predation).
Answer choice (C): This answer presents entirely new information, requiring a rather large assumption on the part of a test taker. Sickness may play a role in predation rates (in fact it seems to), but that doesn’t support the claim that predators can “sense” sickness.
Answer choice (D): This is the correct answer choice. Once again, our prediction serves us well. Birds with smaller spleens tend to be sicklier than other birds, and birds with smaller spleens tend to be killed by predators more often than are other birds. Conclusion? Sickly birds are more likely than healthy birds to be killed by predators.
Pay particular attention to the language used, with the phrase “more likely than” mirroring the nature of the language in the stimulus (“generally”).
Answer choice (E): Attempting to determine causality from the relationship described is a mistake, since we can’t know the cause behind either the reduced spleen size or poor health. It could be that a smaller spleen causes sickness, or it could be that sickness causes a smaller spleen, or it could be a third element that causes both the smaller spleen and the sickliness.
smaller spleens
