Recognizing and Solving Parallel Flaws on the LSAT

The LSAT Logical Reasoning section frequently challenges test-takers with “parallel flaw” questions, where you must identify a flawed argument that mirrors the structure of a given passage. These questions can be among the most time-consuming, but with a clear strategy, they become much more manageable. The video “How to Identify and Recognize LSAT Parallel Flaws Using LawHub Logical Reasoning Drill Set #3” explains a step-by-step approach to solving these tricky questions. Below is a comprehensive guide based on the video.

What Are Parallel Flaw Questions?

Parallel flaw questions require you to analyze an argument, identify its logical flaw, and find an answer choice with a structurally identical error. These questions test your ability to dissect arguments and recognize faulty reasoning patterns. In the featured LSAT drill, the argument involves a custodian defending herself against allegations of theft by presenting a flawed conditional reasoning structure.

The Argument: Understanding the Flawed Logic

The custodian claims:
“If I had stolen and sold the formula, I would have collected a fortune and quit my job. However, I am still working here for minimum wage. Therefore, I must not have stolen the formula.”

Why Is This Flawed?

The argument assumes that because one condition (quitting the job) was not met, neither condition (stealing and selling the formula) could have occurred. This reasoning ignores the possibility that only one of the two conditions was satisfied. Recognizing this type of flaw is critical for finding a parallel argument.

Step-by-Step Strategy for Parallel Flaw Questions

1. Identify the Argument’s Flaw
   Pinpoint the specific logical error in the given argument. In this case, the flaw involves incorrectly negating a conjunction—concluding that neither condition occurred because one was not met.

2. Look for Similar Logical Structures
   Read each answer choice carefully and compare its structure to the original argument. The correct choice must have the same logical flaw.

3. Eliminate Valid Arguments
   Quickly eliminate choices that use valid reasoning, as they do not match the flawed structure of the original argument.

4. Focus on Two-Condition Logic
   In this question, the key to matching the flaw is finding an argument with two conditions, where the failure of one is used to falsely negate the entire conclusion.

Evaluating the Answer Choices

• Choice A: Involves a raccoon, rabies, and a dog. This argument uses valid reasoning to conclude that the raccoon didn’t have rabies. It is not flawed and can be eliminated.

• Choice B: Concerns an election official and two conditions (accepting a bribe and falsifying results). The conclusion incorrectly assumes that because the incumbent didn’t win, neither condition occurred. This matches the flawed reasoning and is the correct answer.

• Choice C: Discusses airplane manufacturers and design flaws. This argument is valid because it logically concludes there were no design flaws after testing. Eliminate.

• Choice D: Involves a snow event’s success based on weather and parking. The conclusion correctly attributes failure to the unmet condition, making it a valid argument. Eliminate.

• Choice E: Features a government official and motive. This reasoning is valid and unrelated to the original argument’s flaw. Eliminate.

Why Choice B Is Correct

The reasoning in Choice B mirrors the original argument by incorrectly concluding that both conditions didn’t occur based on the failure of one. This logical misstep makes it the best match for the parallel flaw.

Tips for Tackling Parallel Flaw Questions

• Focus on Flaw Type: Identify the specific reasoning error before examining the answer choices.
• Ignore Content Details: Concentrate on the logical structure rather than the topic of the arguments.
• Practice Pattern Recognition: Familiarity with common logical flaws will help you quickly spot parallels.

GETTING EXPLANATIONS