Volume III: Reading Comprehension · Chapter 25
The job: Retrieve It. Every correct RC answer is provably in the passage. Read the question, go back to the text, and find it.
Frequency: these types fill all of RC, roughly 27 questions across the scored section. Difficulty: low to high; pacing matters more than any single hard question.
This is a long reference chapter. It walks through every Reading Comprehension question type you will meet: Main Idea and Primary Purpose, Detail (the most common type), Inference, Line and Function, Tone, and the Arguments-style questions imported from Logical Reasoning. For each, you get the same three things: how to recognize the stem, the method, and the traps. Use it as a lookup. When a question stumps you, find its type here and run the method.
One idea sits under all of it. You met it in Chapter 23: Retrieval, not Recall. RC is an open-book test. The correct answer is demonstrably in the passage, and the test is engineered to punish anyone who answers from memory. So the method for every type below begins the same way: after you read the question, go back to the passage and find the answer. Never trust your recollection of what a paragraph said. Your job in Chapter 24 was to build a map (paragraph main points bracketed, connectors circled, key details lightly underlined) so that going back is fast. Now you cash that map in.
Main Idea asks what the passage is arguing. Primary Purpose asks what the passage is doing, described one level more general. They are close cousins and you solve them with the same prep work.
You already did most of the work during your read. In Chapter 24 you built two things: the summary (every paragraph’s main point strung together with conjunctions) and the main point (the single claim the passage exists to argue). The summary contains the main point; it is not the same thing.
For Main Idea, extract the main point portion of your summary, not the whole summary. The summary includes background and support; the main point is the one claim being pushed. Prephrase that claim in your own words, then find the answer that matches it. The right answer usually borrows some language from the passage.
For Primary Purpose, describe the passage’s function one level more general, stripped of topic. Do not say what the passage claims; say what it does. A good prephrase sounds like this: “The passage describes a theory, then raises two objections to it.” Or: “The passage explains an old method, introduces a newer one, and argues the newer one is better.” Then match. This is the same parse-and-match move you use on Principle questions in Logical Reasoning (Chapter 21): break the answer into parts and check each part against what the passage actually did.
A useful tell for Primary Purpose answers is the verb. The choices open with verbs like describe, argue, refute, compare, propose, evaluate, reconcile. Pick the verb that matches the passage’s real work. If the passage takes a side, “describe” is too weak; if the passage only surveys views without judging, “argue” is too strong.
Detail questions are the single most common RC question type, roughly 30 percent of the section. Recognize them by stems that point at what the passage said:
The defining feature: a Detail question asks for something explicitly in the text. You are not reasoning past the passage; you are locating a stated fact.
This is where your map pays off. Run these steps:
The key calibration: the right answer is paraphrased, not quoted. The test disguises the correct choice with synonyms and restructured sentences. A choice that repeats the passage’s exact words is more often a trap (see the contradiction trap below) than the answer. Look for the choice that says the same thing in different words.
The Detail traps are the canonical RC wrong-answer set, taught as a named group in the next section because Inference uses the identical set.
Learn these four as a named group. They appear across Detail and Inference, and recognizing them on sight is the fastest way to eliminate.
When you eliminate on Detail and Inference, name which of these four a choice commits. “Wrong person.” “Too strong.” “Contradiction.” That discipline keeps you from talking yourself into a familiar-sounding loser.
Marine biologists once held that the bioluminescence of the deep-sea anglerfish served only to lure prey. Recent observation complicates this view. While the modified dorsal spine, tipped with light-producing bacteria, does draw small fish toward the angler’s mouth, researchers tracking a population off the Azores noted that females also pulsed the lure in rhythmic patterns when conspecifics passed nearby, behavior the team interprets as a mating signal. The bacteria themselves gain shelter and nutrients from the host; in exchange, the angler cannot produce light without them. Whether the rhythmic pulsing evolved before or after the luring function remains unknown.
Question. According to the passage, the light-producing bacteria benefit from their relationship with the anglerfish in which one of the following ways?
(A) They are able to reproduce more rapidly than free-living bacteria.
(B) They receive shelter and nutrients from the anglerfish.
(C) They allow the anglerfish to attract prey more effectively.
(D) They are protected from the predators that hunt the anglerfish.
(E) They evolved the ability to pulse in rhythmic patterns.
Walk-through. The stem says “according to the passage” and asks specifically how the bacteria benefit. Go back. The relevant line: “The bacteria themselves gain shelter and nutrients from the host.” That is the bacteria’s benefit, stated directly.
(B) paraphrases that line almost one to one (“shelter and nutrients from the host” becomes “shelter and nutrients from the anglerfish”). It is correct.
(A) is outside info on a related topic. The passage never compares the bacteria’s reproduction to free-living bacteria. Plausible-sounding, unsupported.
(C) attributes the benefit to the wrong party. Attracting prey is how the anglerfish benefits from the light, not how the bacteria benefit. This is the wrong-person trap wearing a biology costume.
(D) is outside info. The passage mentions no predators that hunt the anglerfish and never says the bacteria are protected from any such thing.
(E) contradicts the passage by misassigning an action. The anglerfish female does the rhythmic pulsing; the bacteria do not. The choice borrows the real phrase “rhythmic patterns” to sound textual, but pins it on the wrong agent.
The answer is (B).
Here is the single most important reframing in RC. On the LSAT, “inference” does not mean a probable real-world guess. It does not mean “the cat is wet, so it probably fell in the pond.” It means a statement that must be true based solely on the text. You are still doing retrieval, not detective work. You do not import outside knowledge, and you do not speculate about what is likely. You find what the passage’s own statements force to be true.
Inference comes in two kinds, and naming which one you face tells you what move to make:
The approach is the same as Detail: go back, work answer by answer, compare each choice to the text. The wrong-answer set is the same four canonical traps. The one added discipline is the strictness bar. “Most strongly supported” permits the tiniest leap; “can be inferred” or “must be true” is airtight. Calibrate to the stem, but when in doubt, demand that the answer be forced by the text. If you have to add a fact the passage did not give you, the choice is wrong.
Same four as Detail (outside info, contradiction, too strong, wrong person). The trap that does the most damage on Inference is too strong, because the format invites you to “reason,” and reasoning tempts you to extend a cautious claim past where the text supports it. Hold the line: an inference cannot be bolder than its source.
Historians of early printing have long credited movable type with the rapid spread of literacy in sixteenth-century Europe. Eldridge challenges the sequence. Drawing on parish records, she argues that in several regions basic reading instruction expanded for two decades before any local press existed, driven by religious reformers who wanted laypeople to read scripture. Where presses did arrive, they found a readership already forming. Eldridge does not deny that printing accelerated the later, broader diffusion of literacy; she disputes only the claim that printing initiated it. Critics counter that parish records undercount itinerant teachers, but none has yet produced figures that overturn her regional findings.
Question. The passage most strongly supports which one of the following statements about Eldridge’s position?
(A) Movable type played no role in the spread of literacy in sixteenth-century Europe.
(B) Religious reform was the only cause of expanding literacy in every European region.
(C) In at least some regions, demand for reading instruction preceded the arrival of local printing presses.
(D) Parish records are a more reliable source than the figures cited by Eldridge’s critics.
(E) Printing presses were established only in regions where a readership had already formed.
Walk-through. The stem asks what the passage supports about Eldridge’s position. Track her claims carefully, because the passage holds several parties: the traditional historians, Eldridge, and her critics.
(C) is a detail combination drawn straight from her argument: reading instruction “expanded for two decades before any local press existed” in “several regions.” “At least some regions” and “preceded the arrival of local printing presses” restate that, cautiously. It must be true on her account. Correct.
(A) is too strong and contradicts the passage. Eldridge “does not deny that printing accelerated the later, broader diffusion of literacy.” She disputes that printing initiated literacy, not that it played any role at all. The choice overshoots from “did not start it” to “no role.”
(B) is too strong. She cites religious reformers as a driver in “several regions,” not the only cause in every region. “Only” and “every” are unsupported leaps.
(D) attributes a comparison to the wrong source and adds outside info. The passage reports that critics say parish records undercount itinerant teachers; it never says parish records are more reliable than the critics’ figures. The passage in fact notes critics have produced no overturning figures, but that is not a reliability ranking Eldridge endorses.
(E) is too strong, swapping “where presses did arrive, they found a readership already forming” into “presses were established only where a readership had already formed.” That “only” claims presses never appeared anywhere else, which the passage does not support.
The answer is (C).
A specific line, phrase, or word is cited, usually with a line reference, and the question asks one of two things:
Going back is easy here, because the question tells you where to look. The discipline is how much to read. Read the line window: the sentence before, the cited line itself, and especially the sentence after. On the LSAT, a term is very often defined or explained in the sentence right after it appears. If you read only the cited line, you miss the definition the test placed one sentence later.
Then prephrase:
Notice: a Tone question is always about a specific topic, never the whole passage’s general mood. The stem names the target. Honor that target.
Model tone with three components:
Go back to every place the named topic is discussed (use your map), and read the author’s words about it. Then eliminate by valence first, then by intensity. Valence is the fastest lever: if the author is mildly critical of a topic, every positive-valence choice dies at once, and you are down to two or three. Then split on intensity. Everyday version: a friend calls a blind date “nice enough, nothing special.” You catch the valence first, faintly warm but cool, and that alone kills any “thrilled” or “couldn’t stand him” choice on the spot. What is left is an intensity call between something like “mild, polite interest” and “slight letdown.” Valence clears the board; intensity breaks the tie.
Remember the cautious-writing rule. LSAT passages rarely shout. Extreme tone words (“contempt,” “adulation,” “zealous endorsement,” “outright dismissal”) are usually too hot. The credited answer is more often “qualified approval,” “measured skepticism,” or “cautious interest.” Reach for an extreme tone only when the text genuinely carries no caveats. If the author hedged anywhere about the topic, the strong-intensity choice is wrong.
A handful of RC questions import Logical Reasoning tasks. The passage supplies a claim, and you act on it the way you would in LR. There are three forms.
Recognize them by LR-style stems with “if true”: “Which one of the following, if true, would most strengthen the author’s argument?” or “…most weaken the [named] position?”
Apply the same logic as LR Strengthen (Chapter 13) and Weaken (Chapter 14). First, find the claim the question targets and the support the passage gives it. To strengthen, pick the new fact that makes that claim more likely (often a consistent example, or one that rules out an alternative explanation). To weaken, pick the new fact that cuts the support or introduces data inconsistent with the claim. The wrong-answer families are the LR ones: the opposite-direction choice (a weakener planted on a Strengthen, and the reverse), the out-of-scope choice, and the choice that affects a different claim than the one named.
RC Parallel is different from LR Parallel (Chapter 19). There is no conditional diagramming. Instead, you extract a principle from the passage (stated or derived) and apply it to a new scenario. The stem usually begins “Suppose…” or “Which one of the following is most analogous to…”.
A matching scenario has three parts, and all three must line up:
Pull the principle out of the passage, then check each answer against all three parts. The closest LR cousin is the Principle question (Chapter 21), and the method is the same: parse and match, going back and forth between the principle and the candidate scenario until exactly one fits on actor, action, and reason. A choice that matches the topic but not the underlying actor-action-reason structure is bait; a choice that matches the structure on a totally different topic is your answer.
Put it to work: drill every Reading Comprehension question type on full passage sets in the practice platform, free during early access, with every answer choice explained.
