Last updated July 07, 2026 · Reviewed by the AnvayaPrep team
Introduction
Causation and Explanation is one of the highest-frequency domains on the LSAT. Causal arguments and Resolve the Paradox (discrepancy explanation) questions together appear in approximately 15 to 20 percent of all Logical Reasoning questions and are especially common in Weaken, Strengthen, Assumption, and Evaluate questions. Understanding the logic of causal claims and the structure of explanatory arguments is essential for competitive LSAT performance.
The 36 topics in this unit cover the complete landscape of causal and explanatory reasoning: the structure of causal arguments, correlation versus causation, alternative causes, reverse causation, third-variable problems, controlled versus observational studies, natural experiments, causal chains, contributing and preventive causes, temporal sequence evidence, mechanism evidence, causal overstatement and understatement, explaining discrepancies, explaining surprising results, explaining behavior and policy outcomes, evaluating competing explanations, and the traps that appear in answer choices for these question types.
The central tension in this unit is between what the evidence shows (two things occur together) and what causal conclusions are justified (one thing causes the other). Most LSAT causal arguments commit the fundamental error of inferring causation from correlation, and recognizing this error is the first step in answering questions about causal reasoning correctly.
Learning Objectives
- Distinguish correlation from causation and identify when an argument incorrectly infers causation from observed correlation.
- Recognize the three primary challenges to causal arguments: alternative causes, reverse causation, and third-variable explanations.
- Evaluate evidence from controlled studies, observational studies, and natural experiments for its ability to support causal conclusions.
- Identify the structure of Resolve the Paradox questions and apply the correct strategy for finding explanations that reconcile apparent contradictions.
- Predict what would strengthen or weaken a causal argument based on the argument's specific gap.
- Recognize causal overstatement (concluding a necessary or sufficient cause from evidence of a contributing cause) and causal understatement (hedging more than the evidence requires).
- Apply the explanation answer traps checklist to eliminate wrong answers in resolve-the-paradox questions.
High-Yield Concepts
| Causal Concept | Definition | LSAT Application |
|---|---|---|
| Correlation | Two events occur together or vary together | Provides evidence for, but does not establish, causation |
| Causation | One event produces or brings about another | Requires ruling out alternative causes, reverse causation, and third variables |
| Alternative cause | Another factor that could produce the observed effect | The most common weakener for causal arguments |
| Reverse causation | The effect actually causes the supposed cause | Weakens causal arguments when temporal order is uncertain |
| Third variable | A hidden factor that causes both X and Y | Explains correlation without establishing causation |
| Controlled study | Study with experimental and control groups assigned randomly | Strongest evidence for causation; rules out self-selection bias |
| Observational study | Study that observes without random assignment | Weaker causal evidence; subject to confounding variables |
| Natural experiment | An unplanned event that creates conditions resembling random assignment | Intermediate causal evidence strength |
| Causal chain | A -> B -> C where each link must hold for the chain to produce the final effect | Weakened by breaking any single link |
| Contributing cause | A factor that increases the probability of the effect without being necessary or sufficient | Weaker than necessary or sufficient cause |
For any causal argument, ask three questions before reading answer choices: (1) Is there an alternative cause that could explain the effect? (2) Could the relationship be reversed? (3) Is there a third variable causing both? These questions generate the three classic weakeners and the three corresponding assumptions the argument must make.
Study Strategy
Begin by mastering the fundamental distinction between correlation and causation. Every causal argument on the LSAT starts with correlation evidence and draws a causal conclusion. The gap is always that correlation does not prove causation.
Study Resolve the Paradox question structure as its own unit within this larger unit. The structure is: Fact A is true. Fact B is true. Facts A and B seem contradictory. Find the answer that makes both facts true simultaneously. The correct explanation must be consistent with both facts, not just one of them.
Practice applying the alternative-cause and third-variable weakeners to diverse types of causal arguments: medical, environmental, economic, social science, and behavioral. The application is the same regardless of subject matter.
Study the experimental design topics (controlled studies, observational studies, natural experiments) to understand what types of evidence can and cannot support causal conclusions. These appear in Strengthen, Weaken, and Evaluate questions.
Correlation = "they happen together." Causation = "one makes the other happen." These are not the same. Ice cream sales and drowning deaths both increase in summer, but ice cream does not cause drowning. Hot weather (third variable) causes both. This classic example encodes the third-variable pattern permanently.
Common Mistakes
Accepting temporal sequence as causation. If A happens before B, it does not follow that A caused B. This is the post hoc fallacy. The LSAT frequently presents temporal sequence as causal evidence and asks whether students can identify the flaw.
Forgetting to check for reverse causation. If A and B are correlated, it might be that B causes A rather than A causes B. Students often accept a causal direction without questioning whether it could be reversed.
Missing the third variable. Correlation between A and B might be explained by a third factor C that independently causes both A and B. Many LSAT causal weakeners present this third variable.
Selecting a resolution to a paradox that explains only one fact. In Resolve the Paradox questions, the correct explanation must make both apparently contradictory facts true simultaneously. An answer that explains Fact A but makes Fact B even more surprising is wrong.
Confusing a contributing cause with a necessary or sufficient cause. An argument that uses evidence of a contributing factor to establish a necessary or sufficient causal claim is overstating the causal relationship. This is a common flaw.
Exam Tips
On causal arguments, identify: (1) the cause being claimed, (2) the effect being explained, (3) the evidence given (usually correlation or temporal sequence), and (4) the gap between evidence and conclusion.
For Resolve the Paradox questions, read both paradoxical facts carefully and ask what kind of information would make both true. Pre-phrase: "I need an answer that explains why Fact A is true despite Fact B also being true." This narrows the answer choices immediately.
Wrong answers in Resolve the Paradox questions typically: (a) explain one fact but make the other more surprising, (b) explain a different contradiction than the one presented, (c) introduce irrelevant information, or (d) deepen the paradox rather than resolve it.
Do not select a Resolve the Paradox answer that makes perfect sense intuitively but contradicts one of the stated facts. The correct answer must be consistent with everything stated in the stimulus. If an otherwise compelling explanation would require the stimulus to be wrong on any point, it is a wrong answer.
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