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Reading Comprehension: Main Idea Questions

The author of the passage is mainly concerned with



Although this answer choice correctly summarizes many of the topics of the passage, it does not include the information presented in the first paragraph, making it too narrow

Great job!


We know that corn has brought benefit to our society today, and yet in the past its late evolution may have brought disaster upon pre-Columbian peoples (as Jared Diamond suggests). However, the author debates this point of view, offering evidence that contradicts Diamond's theory.



It was the relatively late evolution of corn, not the use of teosinte, that may have led to the downfall of pre-Columbian American societies. The second paragraph, in which teosinte is discussed, does not discuss the use of teosinte, if it in fact was used at all.



This answer choice incorrectly represents the author's opinion of Diamond's theory. The author, although he or she praises Diamond's eloquence, does not support his ideas.



Diamond's theory does not propose that the use of corn led to the downfall of pre-Columbian societies but that the effects of corn's late evolution were responsible.

You're right, this passage is one of the harder ones, in which you may need to adjust your approach to the Initial Reading a bit. Remember that the Initial Reading is an excellent guideline, but it is not an exact science.

For the first paragraph, read until you get the general idea. 1-3 sentences should be sufficient, but there's no clear cut definition. When the paragraph starts to drag you into the specifics, move on. For the other paragraphs, read the first sentence carefully, but you can also skim the next couple of sentences (read quickly, without bothering to understand or memorize), just to see that there are no major changes in the main idea of the paragraph, as presented in the first sentence.

Yes, definitely. Stay on the lookout for Structural Words. If you have performed the Initial Reading for a paragraph and read just one sentence, but then notice a structural word that indicates a shift - read on a bit more.


Did you notice the word "however" in the last paragraph?

The first sentence of that paragraph seems to support Diamond's theory, but a glance at the next sentence reveals the structural word "however"; structural words such as "however", "despite", "contrarily", etc. act as signposts that the argument's direction is reversed from that point onwards.

If you see that the next sentence begins with such a word, it's a good idea to add that sentence to your Initial Reading and check whether the first sentence was indeed misleading.

Do that - and remember that you should basically trust the Initial Reading and eliminate answer choices aggressively.

Shall we review the process of elimination for this question?

The process should be as follows:

Eliminate the more obvious answer choices that clearly do not match the main idea from the Initial Reading:

  • Answer choice C is too specific because it excludes information from the first paragraph,
  • D is suspect because it puts Prof. Jared on a pedestal  ("argues so elegantly") which the last paragraph takes him down from;
  • E is incorrect because it's not the use of corn that brought the downfall - it's teosinte's evolutionary path.

Between B and A, if you really feel the need to know whether there were conflicts or not (as A states), then go ahead and read the third paragraph more fully, where you will find mention of the defeat of the pre-Columbians.

Regarding B, it could be argued that the passage does not really compare the use of corn to the use of teosinte - both were used extensively, and the comparison is between the evolutionary paths both took, not between their relevant use. You therefore have grounds for eliminating B.

However, if you cannot retain this fine point from the Initial Reading, then by all means go back to the text to confirm your reason for eliminating.

Indeed. Just remember to ask yourself "Have I read enough to know the answer with a high degree of certainty? Do I really need to read more?"

debating the negative influence of corn's evolutionary development on the conflicts between the pre-Columbian Americans and Europeans, in contrast to corn's positive influence on our society today
comparing the uses of corn in the present to the use of teosinte in the past, which led pre-Columbian American societies to develop in drastically different ways from their European counterparts, possibly leading to the former's downfall
arguing against the theories of Jared Diamond which stipulate that corn's late evolutionary development caused Native American societies to develop later than European societies, leading to the former's downfall
discussing the effects of corn on both the current American society and the pre-Columbian American society, which, as Jared Diamond argues so elegantly, caused the latter's downfall in its conflict with the Europeans
explaining the benefits of corn's use today and explaining how the theory that corn's use by pre-Columbian American societies put them at a disadvantage in comparison to European societies is at odds with today's knowledge of the former
Whew! That was hard. I wasn't sure how to solve this based only on the Initial Reading.
Any more tips?
Would this approach have worked for this question?
Okay, I'll keep my eyes peeled for structural words.
Please do
So that leave us with a choice between A and B.
So this is what it means to "adjust" the Initial Reading?