LSAT Explanation PT 32, S1, Q22: Most people who shop for groceries

LSAT Question Stem

Which one of the following arguments has a flawed pattern of reasoning most like the flawed reasoning in the argument above? 

Logical Reasoning Question Type

This is a Parallel Flaw question. 

Correct Answer

The correct answer to this question is D. 

LSAT Question Complete Explanation

Let's break down the argument in the passage first. The structure of the argument is as follows:

Premise 1: Most people who shop for groceries no more than three times a month buy prepared frozen dinners regularly.

Premise 2: In Hallstown, most people shop for groceries no more than three times a month.

Conclusion: In Hallstown, most people buy prepared frozen dinners regularly.

The argument commits an error of division by assuming that a general proposition about "most people" will apply to any subset of that group, such as the people in Hallstown. To help you understand this error, consider the following example: Most people who watch TV enjoy sitcoms. In a particular town, most people watch TV. Therefore, in that town, most people enjoy sitcoms. This is not necessarily true, as the town could have different preferences than the general population.

An "Evaluate" question for this argument could be: "Do the shopping habits of people in Hallstown follow the same pattern as the general population?"

Now, let's analyze the answer choices. The question type is Parallel Flaw, which asks us to find an answer choice with a flawed pattern of reasoning most like the flawed reasoning in the argument above.

a) This answer choice contains the phrase "very few," which is different from "most." The structure of this argument is not parallel to the original argument, so it is incorrect.

b) This answer choice contains the phrases "cannot" and "no one," both of which are different from "most." The structure of this argument is not parallel to the original argument, so it is incorrect.

c) This answer choice contains the phrase "usually," which is a synonym for "most," but the two "all" statements are different enough from the original argument's structure to make this answer choice incorrect.

d) This is the correct answer choice, as it has a similar structure to the original argument with three "most" statements. Both arguments commit the error of division by assuming that a general proposition about "most people" will apply to any subset of that group.

e) This answer choice contains a conditional premise (introduced by "only"), which is not present in the original argument. The structure of this argument is not parallel to the original argument, so it is incorrect.

In conclusion, the correct answer choice is (D), as it closely parallels the flawed reasoning in the original argument. Remember to focus on the structure and distinctive elements of the argument when tackling Parallel Reasoning questions to help you eliminate incorrect answer choices quickly and efficiently.