#21 - Must Be True

[Administrator]

Complete Question Explanation
(See the complete passage discussion here: lsat/viewtopic.php?t=7945)

The correct answer choice is (D)

This Passage Relationship question asks us to identify the abstract relationship between the evidence
from Ban Chiang discussed in Passage B and the generalization reported in the second paragraph of
Passage A (lines 20-22). Recall that the generalization reported in Passage A concerned the positive
correlation between a population’s dependence on agriculture and its rate of caries formation. By
contrast, as the Ban Chiang populations became increasingly dependent on agriculture, their caries
frequency decreased. This suggests that the evidence from Ban Chiang is inconsistent with the
generalization reported in Passage A.

Answer choice (A): This is an Opposite answer, since the evidence from Ban Chiang does not
confirm the correlation between agricultural intensification and caries formation.

Answer choice (B): This is an Opposite answer, similar to answer choice (A). The evidence from
Ban Chiang does not support the correlation described in Passage A.

Answer choice (C): The evidence from Ban Chiang is inconsistent with the generalization reported
in Passage A, not irrelevant to it.

Answer choice (D): This is the correct answer. The Ban Chiang exhibited a negative correlation
between caries rates and agricultural dependence, which is inconsistent with the positive correlation
reported in the second paragraph of Passage A. Therefore, the evidence from Ban Chiang does not
conform to the generalization.

Answer choice (E): This answer choice contains an exaggeration. Just because some facts are
inconsistent with a particular generalization does not mean that the generalization is thereby
disproven.

[ubrjames]

I chose answer choice B and answer choice D is correct. During my blind review, I liked answer choice D, but then reviewed passage B again and chose answer choice B again.

The generalization of comparison was that reliance on agriculture led to high rates of caries formation. Passage B tended to support that until information was introduced that the Late Group had less caries than the Early Group, even though the Late Group depended more on agriculture than the Early Group.

The passage then states that a possible explanation is that the diet of the Late Group remained varied enough to avoid higher rates of caries.

Isn't that contradictory? If there diet was varied, then how could it be entirely dependent on agriculture? The passage goes as far to suggest that the late group relied on other foods and that no foods dominated. If no food dominated, how is it possible that the Late Group was "dependent" on agriculture?

Those were the questions I used in determining that answer choice B was a better answer than answer choice D.

Thanks for any help.

-James

[Claire Horan]

Hi James,

You have articulated well the first passage's generalization. I would say the generalization is more that, as societies moved to agriculture, their rate of tooth caries increased. Both formations of the generalization are fine.

The second passage doesn't say that the Ban Chiang people were entirely dependent on agriculture, only that their reliance increased. This isn't contradictory, but I'm not sure it matters in any case. The society in passage B was expected to show a higher rate of tooth caries after they started growing crops, but instead they showed fewer caries. In other words, "(D) The evidence does not conform to the generalization."

(B) would be correct if the second passage gave an example in which a society began growing crops and their caries increased. So even if you misunderstood the part of the passage about their later diets, that reasoning still should not lead to (B).