LSAT RC Passages That Present Two Competing Theories

A competing-theories passage introduces one explanation for something, then brings in a rival that challenges it, and the author either sides with one, splits the difference, or stays out of it. Everything the questions ask about follows from three moving parts: theory A, theory B, and the author's position relative to both.

This is a single passage, not a paired set. The whole structure lives inside one continuous text with one author, which is why the attribution problem is harder here. Read it as a map rather than a story: record who holds what, what evidence backs each, and where the author's own voice shows up.

You can usually identify this structure within the first paragraph and a half. The opening establishes a phenomenon that needs explaining — a shift in a bird species' range, an odd pattern in a legal doctrine — and offers an account of it, often flagged as the traditional one.

The tell that a second theory is coming is attributive language around the first: "the standard account holds," "scholars have long maintained," "the prevailing view attributes." When a passage takes the trouble to label a theory as someone's, it is usually setting up someone else's. Confirm it at the first contrast marker — "however," "more recently," "this account has been challenged" — and map from there.

This structure is easy to confuse with the paired Comparative Reading set, and the difference changes what the questions can ask. A two-passage set has two separate authors, and its questions ask how the passages relate — agreement, disagreement, what one author would say about the other's claim.

In a single competing-theories passage there is exactly one author. The two theories are objects the author is describing, not voices with equal standing. That means the author can quietly endorse one, criticize both, or hold back — and the questions will test whether you noticed which.

The practical consequence: in a paired set you track two authors; here you track three viewpoints — proponents of A, proponents of B, and the author — with the third being the only one that can be absent. For the two-passage version of this work, see the guide to Comparative Reading passages.

Who holds each theory. Attach a name or group to every claim as you read — "the traditional account," "critics." A claim floating without an owner is one you will misattribute later. If the passage names no owner, note that too: an unowned claim is often the author's.

What evidence supports each. Questions frequently ask which finding a given camp would cite, so keep each piece of evidence attached to the theory it serves rather than pooling everything into one fact heap.

Where the author's voice enters. Author voice shows up in evaluative adjectives ("a persuasive reinterpretation," "an implausible leap"), in unattributed assertions, and in the framing of a concession ("although the traditional account explains the timing, it cannot account for the distribution"). That last construction is the author speaking even though both clauses are about other people's theories.

Most competing-theories passages turn on a single sentence, and finding it is the highest-value thing you do on the first read. The pivot is where theory A stops being presented and starts being pressured — typically a sentence turning on "however," "yet," or "more recent work suggests."

What matters is the grammar of that sentence, not its position. If the pivot reads "Recent excavations, however, have complicated this account," the author is reporting that a challenge exists. If it reads "This account, however, cannot explain why the pattern reverses," the author is delivering the challenge personally. The first is description; the second is a position. Main point, purpose, and attitude questions all resolve against that distinction, so slow down and ask whose mouth the objection comes out of.

Because the architecture is stable, the question set is predictable. Map each element to the questions it feeds and you can anticipate the stems.

Notice how many rows return to one question: is the author reporting or judging?

"For most of the past century, ornithologists attributed the northward shift in the warbler's breeding range to rising average temperatures. Recently, however, several researchers have proposed an alternative: that changes in agricultural practice, which expanded the insect populations the warbler feeds on, drove the shift independently of temperature. Proponents of this view point to inland valleys where the range moved north despite no measurable warming. The temperature account, for its part, still explains cases where farming patterns were unchanged. Neither factor alone accounts for the full pattern."

Map it. Theory A: warming temperatures, held by ornithologists. Theory B: agricultural change, held by recent researchers, supported by the inland valleys. The pivot — "Recently, however, several researchers have proposed" — is reporting: the author says a challenge exists, not that it succeeds. Then find the author. The last sentence is unattributed and evaluative, and that makes "neither factor alone accounts for the full pattern" the author's own claim and the main point.

Tempting wrong answer for a main point question: "Recent research has shown that changes in agricultural practice, rather than rising temperatures, caused the warbler's northward shift." It fails twice over — it picks a winner the author declines to pick, and it hands theory B's claim to the passage as a whole. The sentence beginning "the temperature account, for its part" is there precisely to block that answer.

The dominant error is treating a theory the author describes as a theory the author holds. It happens most often with the second theory, because the newer view arrives after a contrast word and contrast words usually announce the author's turn. Here they often announce someone else's.

The mechanism is that attribution decays as you read. The passage says "several researchers proposed" once, in paragraph two, and by paragraph four you have read twenty lines of their claims with no reminder of whose they are. Renewing the attribution as you go — a marginal "B" next to their evidence — is what prevents it.

There is a mirror error worth naming: assuming the author must have a side. Some competing-theories passages are genuinely balanced, and the credited main point is that the debate is unresolved. Go hunting for an endorsement and you will manufacture one out of neutral reporting.

The check that catches both: before the questions, say in one sentence what the author thinks, then find the line that proves it. If you cannot find the line, the author probably has not told you — which is frequently the correct reading rather than a failure of yours.