Simple Guide on Parallel Reasoning Questions

Intro to Parallel Reasoning Questions

This blog is a part of the “Approach Question Type” series and like all articles in this series will focus on step 4 of the “Analyze Stimulus” step. If you need a refresher on how to approach LR questions generally, make sure to check up on our blog "How to Approach the Logical Reasoning Section.”

‍Table of Contents:

• What is a Parallel Reasoning Question?
• Approach
• Example Walkthrough

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What is a Parallel Reasoning Question?

Parallel reasoning questions on the LSAT require you to identify a reasoning pattern in the stimulus and then find the answer choice that has the same pattern. This is a test of our formal logic skills — we are meant to find the same pattern of reasoning, and therefore these types of questions may be diagrammed in symbolic logic. The pattern may be logically sound or flawed. 

The skill practiced in parallel reasoning questions is very relevant to the study of the American common law system because the precedent of previous cases is used as analogical support to argue for conclusions in the present and future. In this way, we need to be adept at deciphering the parallel reasoning, if sound, to apply to present and future conclusions, and if flawed parallel reasoning, to diagnose them as so.

Question Stems

• “Which one of the following arguments is most similar in its reasoning to the argument above?”
• “The reasoning in the argument above is most similar to that in which one of the following?”
• “Which one of the following arguments exhibits a flawed pattern of reasoning most similar to that exhibited by the argument above?”

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Approach

Our focus is on the logical process the writer uses to reach their conclusion, not on the specific content or subject matter. Pay attention to how the argument is structured in relation to the premises. In a parallel flaw question, the way in which the premises connect to the conclusion will present faulty reasoning. We must be able to spot this flaw so then we can recreate the pattern.

If you are struggling with parallel flaw questions, it might be beneficial for you to revisit our guide on flaw questions; building your foundational skills is key to breaking down the more complex questions on the LSAT. 

In parallel reasoning, we accept that the reasoning is sound, and focus on precisely how the author structures the premises to arrive at the conclusion. Be on the lookout for formal logical connections, diagram where applicable.

1. Identify the conclusion
2. Separate out the premise / evidence components
3. Analyze how the author arrives at the conclusion. Attribute symbolic logic to argument structure to match with answer choices.

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Examples Walkthrough

Argument 1:

"Every time a company lowers its prices, its competitors follow suit. Given that TechCo just implemented a price reduction in their products, we can expect its competitors to do the same shortly."

1. Identify conclusion: “Given that TechCo just implemented a price reduction in their products, we can expect its competitors to do the same shortly."some text
   1. TechCo lowered price → competitors follow
2. Evidence: "Every time a company lowers its prices, its competitors follow suit.” some text
   1. If lower price → others follow 
3. How did the author arrive at conclusion? some text
   1. Because If lower price → others will follow. TechCo lowered price → therefore others follow.

Our goal is to find a logically sound argument where we are told the premise that A→B and a parallel scenario where someone satisfies condition A and therefore B will occur. 

"Which one of the following arguments is most similar in its reasoning to the argument above?"

Answer Choices:

1. Whenever a politician makes a promise during an election, they often break it afterward. Since Candidate X made a lot of promises during their campaign, it's likely they will break them 
2. Every time a restaurant offers a discount, it attracts more customers. Since DineWell just started offering a discount, we can expect it to see an increase in customers.
3. If a movie receives good reviews, it usually performs well at the box office financially. The new movie just received excellent reviews, so it is likely to do well with critics.
4. Whenever it rains, everyone will carry an umbrella. People are carrying umbrellas today, so it must be raining today.
5. Whenever a city hosts a major event, traffic increases significantly. Since a minor event is being held downtown this weekend, traffic will increase.

Answer Analysis:

1. This is close, but the key difference is “often,” which makes it A→ Likely B. So, this is still in the realm of likelihood, rather than certainty of “every time.”
2. Correct answer! This is the same parallel reasoning as the stimulus, as we have a situation every time A → B occurs, and a conclusion that satisfies the condition.
3. Similar to A, this is “usually” which we are uncertain of the likelihood of B occurring (performing well financially). Furthermore, the second sentence mentions doing well with critics, which is different from the logical condition presented of financial success.
4. This is incorrect as it reverses the logic of sufficient and necessary. 
5. This is incorrect as the second sentence of the conclusion mentions “minor” event rather than major event. If it said major event, then it would be correct!

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Argument 2: "Everyone who attends law school is either highly intelligent or extremely hardworking. Since Sarah is highly intelligent, she must attend law school."

1. Identify conclusion: “Sarah attends law school”
2. Evidence: "Everyone who attends law school is either highly intelligent or extremely hardworking, and Sarah is highly intelligent.”
3. How did the author arrive at this flawed conclusion? some text
   1. Logic:
   2. If attend law school → intelligent or hardworking
   3. Sarah is intelligent → attends law school
   4. Flaw: confuses sufficient and necessary condition

Our goal is to find a parallel flaw that confuses the sufficient and necessary conditions of a logical chain.

Question Stem: "Which one of the following arguments contains flawed reasoning most similar to that in the argument above?"

Answer Choices:

1. All musicians are creative or disciplined. Since Alice is a musician, she must be talented at piano.
2. All people who work at the tech company are either engineers or designers. Since Maria works at the tech company, she must either be an engineer or designer.
3. Everyone who plays chess is either strategic or analytical. Since Daniel is strategic, he must also be analytical.
4. All writers are either imaginative or knowledgeable in literature. Since Carlos is a writer, he must be imaginative
5. All professional athletes are either very talented or exceptionally dedicated. Since John is very talented, he must be a professional athlete.

Answers Analysis

1. This is not a sufficient and necessary condition swap. The flaw here is introducing a conclusion (Alice being good at piano) outside of the information provided to us. 
2. This is not a flaw. This is logically sound.
3. The flaw is that we do not know the relationship between being strategic and being analytical as a necessary condition. Daniel may or may not be analytical on top of being strategic.
4. This is not a flaw. This is logically sound.
5. This is the correct parallel flaw. All professional athletes are either talented or dedicated. But just because John is talented doesn’t mean he is a professional athlete.