Self-study
Support Members of the Amazonian Akabe people commonly take an early-morning drink of a tea made from the leaves of a forest plant. ████████ ████ ███████ █████ ████ ██████ ██ ████ ████ █████ ██ ████ ██ █████ ████████ ███████████████ ███████████ ████ █████ ████ ███ ██ ███████████████ ████ ██ █████████ ███ ███████████ ███ ███ █████████ ███ ████████ ████ ██ ██ ██ ████ ██ ████ ████ ████████ ██████ █████ ███████ ███ ██████████████ ████ █████ █████ █████ ████████
Structure: Phenomenon-Hypothesis
The stimulus reports a certain phenomenon: though the Akabe people enjoy this tea, they only drink it in small amounts at dawn. Some anthropologists provide a hypothesis to explain this phenomenon: since this tea has very high levels of caffeine, drinking too much of it at dawn would destroy the "surefootedness" that the Akabe need for their daily tasks.
Analysis: Potential Weakeners
The anthropologists suggest that the cause of the phenomenon is the potentially negative effects that too much caffeine would have on the Akabe people's daily tasks. We could directly weaken this causal hypothesis — for example, by showing that higher caffeine intake would actually increase, not decrease the Akabe people's "surefootedness" — or we could weaken the argument simply by providing an alternative explanation. For example, perhaps the Akabe believe this tea has a ceremonial significance, and drinking too much of it would be disrespectful. Or perhaps the tea contains some other substance that would be even more harmful than caffeine if consumed in large quantities. Either way, the direct cause of the phenomenon would have nothing to do with caffeine, so the anthropologists' hypothesis would be undermined.
17.
Which one of the following, ██ █████ ████ █████████ █████ ███ ██████████████████ ███████████ ████ █████████
a
The drink is ████ ██ █████████ █████████ ██████ ████ ███ █████ █████
This might seem like it makes the phenomenon more puzzling: if the tea contains nutrients that the Akabe can't get from anywhere else in their diet, why do they drink so little of it? But first, we don't know how large a dose of these nutrients they require — maybe they get a large enough dose from even a small amount of tea. And second, this statement, even if true, doesn't undermine the anthropologists' explanation. Maybe the Akabe would benefit from drinking more of this tea to get more nutrients, but they don't because consuming all that caffeine would have a negative effect on their daily tasks. So (A) doesn't weaken the anthropologists' hypothesis.
b
The Akabe also █████ ███ ███ ██ ███ ████████ █████ █████ ███████ ████ ██ █████
Incorrect. If you picked (B), you might have thought the Akabe wouldn't drink a caffeine-rich drink in the evening. But that reasoning smuggles in an unwarranted assumption. We don't know how much of this tea the Akabe drink in the evening, or at what point in the evening they drink it. Maybe they drink it quite early in the evening, and drink even less of it than they do at dawn. Without more details, this fact on its own doesn't give us a reason to doubt the anthropologists' theory about why the Akabe don't drink more tea at dawn.
In fact, you could even read (B) as strengthening the anthropologists' hypothesis. Remember that according to the anthropologists, the reason the Akabe don't drink much of this tea at dawn is to preserve the "surefootedness" they need for their daily tasks. This answer choice specifically states that the Akabe drink this tea "after their day's work is done" — i.e., when they no longer need to be surefooted. Thus, this answer choice could strengthen the idea that the Akabe avoid drinking more of this tea at dawn specifically to avoid losing surefootedness. (B) certainly doesn't weaken the anthropologists' argument.
c
The leaves used ███ ███ ███ ███████ █ ███████ █████████
Correct. Notice that this answer choice doesn't deny that the tea contains a high amount of caffeine, or that drinking too much of it might also produce negative effects from caffeine. But this answer choice does provide an alternate explanation for why the Akabe might not drink more tea in the morning. Maybe they aren't worried about the effects of the caffeine, and are instead trying to avoid the effects of too much of this narcotic. By providing an alternate explanation, (C) effectively weakens the anthropologists' hypothesis.
d
Akabe children are ██████████ ██ ███ ███ ██ ████ █ ████ ████ █████
This answer choice doesn't weaken the hypothesis. (D) could be perfectly consistent with the anthropologists' explanation. Maybe the reason children are introduced to the tea in a weak form is precisely that it contains so much caffeine.
e
When celebrating, the █████ █████ ███ ███ ██ █████ ███████████
Irrelevant. This could fit perfectly well with the anthropologists' hypothesis that the reason the Akabe don't drink more tea each day at dawn is to avoid negative effects for their daily tasks. We don't know if the Akabe need to perform daily tasks on days with ceremonies, so (E) doesn't undermine the anthropologists' hypothesis.