Prior to the nineteenth century, both human and animal populations wer

Q1)Step 2: Analyze the Question Stem
This Global question asks us for the passage’s “primary purpose.”
Step 3: Research the Relevant Text
A quick look at our notes on topic, scope, and purpose will suffice. There’s no need to go back to the passage itself to answer a Global question.
Step 4: Make a Prediction
Our notes say that the author’s purpose is to describe two different explanations for why families tend to decrease in size with increasing prosperity. In evaluating the choices, it will also help to recall that the author’s point of view in this passage is entirely neutral.
Step 5: Evaluate the Answer Choices
In evaluating the choices for a “primary purpose” question, it is often useful to start with a scan of the initial verb. (D) starts with the verb “present,” which is perfectly neutral and very close to our
description of the author’s purpose, which we said is to “describe” two alternate explanations. This should be the choice we read first. When we do, we find that is a perfect match for our prediction. (D) is in fact the correct answer. (A) is incorrect because the author doesn’t “criticize” anything. (B) is incorrect because events that occurred “before the Industrial Revolution” are outside the scope
of the passage. (C) is incorrect because the author fails to “demonstrate” that either or both of the explanations described have any merit. (E) is incorrect because the author doesn’t “argue” for or
against anything. Choice (D) is correct.

Q2)Step 2: Analyze the Question Stem
“According to” signals that this is a Detail question. The correct answer will simply paraphrase a detail mentioned in the passage.
Step 3: Research the Relevant Text
The “Malthusian explosion in population” is mentioned in the first paragraph, where we really only learn two things about it: (1) It was “expected” by scientists at the time of the Industrial Revolution, and (2) it didn’t actually happen.
Step 4: Make a Prediction
For Detail questions, what we’ve found through our research amounts to our prediction. We need an answer choice that says either that a Malthusian population explosion was expected, or that it
did not actually occur, or both.
Step 5: Evaluate the Answer Choices
(C) matches our prediction and is the correct answer. (A) is incorrect because “preindustrial areas of the globe” are outside the scope of the passage. All we know is that there has not been a population
explosion in industrialized nations; what has happened elsewhere is not discussed in the passage. (B) is the opposite of what we need. The first paragraph of the passage states that a Malthusian
population explosion, though believed to be inevitable during or after the Industrial Revolution, did not actually occur. As for (D), the closest thing to “social scientists” mentioned in the passage
would be the “critics” of the early biologists. However, the passage does not state whether there is a “consensus” among these critics’ views or when such a “consensus” was arrived at. (D) is thus
outside the scope of the passage. Finally, (E) is a distortion. The population explosion was avoided, according to the passage, for one of the two possible reasons put forth by the “early biologists” and
their “critics,” respectively. While the critics’ explanation does include extended education as an economic liability that helps convince people in industrialized nations to have fewer children, the
author of the passage does not endorse the critics’ explanation as correct. Choice (C) is the correct answer.

Q3)Step 2: Analyze the Question Stem
This question asks us for the function of the final paragraph and is thus a Logic question. Logic questions are essentially code for “Why did the author bother to include this part of the passage?”
Step 3: Research the Relevant Text
Because we are being asked for the function of the third paragraph in the passage as a whole, we should cast a quick glance at our Passage Map. The first paragraph introduces the curious fact that
family size has declined in industrialized nations, the second paragraph gives the early biologists’ explanation for this phenomenon, and the third paragraph presents the critics’ explanation.
Step 4: Make a Prediction
The author’s point of view in this passage is completely neutral; there is no endorsement of one or the other explanation for decreasing family size. The third paragraph, then, simply describes one
of two possible explanations.
Step 5: Evaluate the Answer Choices
(A) matches our prediction and is the correct answer. The “phenomenon described in the first paragraph” is the decline in family size in industrialized nations. (B) is incorrect because the
function of the third paragraph is simply to present another explanation. The author of the passage doesn’t “criticize” either explanation (though the critics do). (C) is incorrect because while the critics’ argument is precisely that social attitudes change as societies become wealthier, this is again not necessarily the author’s opinion. We must always keep the author’s perspective in mind
when answering Logic questions. (D) is incorrect because the “phenomenon” explained in the third paragraph was originally presented in the first paragraph, not the second. Finally, (E) is incorrect
for the same reason that (B) and (C) are incorrect: The idea that changing social attitudes are sufficient to explain decreasing family size in industrialized nations is not endorsed by the author. The third paragraph simply presents the critics’ argument; the author doesn’t evaluate that argument at all. Choice (A) is the correct answer.

Q4)Step 2: Analyze the Question Stem
This question asks for the one answer choice not specifically mentioned in the passage, so we have a Detail EXCEPT question.
Step 3: Research the Relevant Text
We’ll need to look up each answer choice to rule out those that are mentioned in the passage. The question stem directs us to the second and third paragraphs, as those paragraphs contain the explanations for why family size tends to fall in industrialized nations.
Step 4: Make a Prediction
For Detail EXCEPT questions, we’ll have to look up the answer choices individually. We’re looking for that answer choice that is not mentioned in the passage.
Step 5: Evaluate the Answer Choices
(A) is incorrect because lengthy education that makes children a drain on family resources is mentioned in the third paragraph as part of the critics’ explanation. (B) is incorrect because advantaged
children out-competing disadvantaged ones comes up at the end of the second paragraph as part of the early biologists’ explanation. (C) is incorrect because improved social care of the elderly is mentioned during the critics’ explanation in the third paragraph. The “changed social attitudes” in (D) form the crux of the critics’ explanation, so (D) is incorrect. (E) must, by default, be the correct answer. Indeed, the second-to-last sentence in the third paragraph states that in industrialized societies, physical labor becomes less important, not more so. (E) states the opposite of what the passage says and is therefore correct.

Q5)Step 2: Analyze the Question Stem
The word “suggests” in the question stem signals an Inference question.
Step 3: Research the Relevant Text
The question stem directs us to the early biologists’ comparison, in the second paragraph, of human family sizes to the reproductive patterns of animals living in different environments. We learn that
animals that have many young “tend to live in hostile, unpredictable environments,” while animals that have fewer young “tend to live in stable, less hostile environments” and “invest more resources
in childrearing.”
Step 4: Make a Prediction
The question asks for an animal that has many young. We can expect the correct answer to describe an animal that lives in a harsh environment. Moreover, while the passage does not explicitly say so,
we can infer that the animal with many young will provide minimal care for its offspring.
Step 5: Evaluate the Answer Choices
(E) matches our prediction and is the correct answer. An animal that lives in “seasonal streams and lakes” certainly lives in an unpredictable environment, since those bodies of water are prone
to drying up. Moreover, the presence of many predators certainly contributes to a very harsh environment. (A) might look tempting because a drought-susceptible grassland definitely qualifies as a
hostile and unpredictable environment, but we would not expect an animal that has many offspring to be “fiercely protective” of those offspring. (A) is thus a perfect example of a half-right/half-wrong answer choice. (B) is incorrect because while the islands are threatened by human encroachment, they may nevertheless constitute a stable, friendly natural environment. (C) is incorrect because even though the meat eater has to migrate in search of food, there is no suggestion that food is ever unavailable, and the lack of predators implies a non-hostile environment. (D) is incorrect because
little competition again suggests a non-hostile environment. Choice (E) is correct.

Q6)Step 2: Analyze the Question Stem
The phrase “in order to” indicates that this is a Logic question. Specifically, we are asked why the author mentions a decrease in the importance of physical labor.
Step 3: Research the Relevant Text
The question stem sends us to line 28, which is in the middle of the third paragraph. That paragraph begins with the critics’ argument, which is that “changes in social attitudes are adequate
to explain” shrinking family size in industrialized nations. The rest of the paragraph contains the critics’ evidence for their position.
Step 4: Make a Prediction
Physical labor’s diminishing importance is a social phenomenon that helps to bring about a change in social attitudes, so it is essentially a piece of evidence for the critics’ argument.
Step 5: Evaluate the Answer Choices
(A) matches our prediction and is the correct answer. (B) is a distortion. The critics’ argument counters that of the early biologists, not the argument of those scientists alive at the time of the
Industrial Revolution who predicted a Malthusian population explosion. (C) is another distortion. It’s family size that the critics contest must change to meet the demands of a changing economy,
not family “structures.” (D) falls outside the scope of the passage. The author doesn’t rebut any argument; the tone of the passage is perfectly neutral. Finally, (E) is another distortion. The critics
argue that large families can increase family income in preindustrial societies “tied to the land.” But a decrease in the importance of physical labor happens in industrial societies, not in preindustrial ones. Choice (A) is correct.