LSAT Explanation PT 45, S4, Q20: Polling data reveal that an overwhelming

LSAT Question Stem

Which one of the following uses flawed reasoning most similar to the flawed reasoning above? 

Logical Reasoning Question Type

This is a Parallel Flaw question. 

Correct Answer

The correct answer to this question is A. 

LSAT Question Complete Explanation

Let's first analyze the argument in the passage. The passage states that a majority of nine-year-olds can identify cigarette brand logos, but less than 1 percent of them smoke. The conclusion drawn from this is that there is little or no connection between recognition of cigarette brand logos and smoking. The structure of the argument can be broken down as follows:

Premise 1: Majority of nine-year-olds can identify cigarette brand logos.

Premise 2: Less than 1% of these nine-year-olds smoke.

Conclusion: There is little or no connection between recognition of cigarette brand logos and smoking.

To better understand this argument, let's use a simple example. Imagine a group of children who can recognize the logo of a popular soda brand. However, only a small percentage of them actually drink that soda. Based on this information, one might conclude that there is little or no connection between recognizing the soda brand logo and actually drinking the soda.

An "Evaluate" question for this argument could be: "Do these nine-year-olds have the opportunity and means to start smoking?"

Now, let's discuss the question type and the answer choices. The question type is Parallel Flaw, which means we need to find the answer choice that has flawed reasoning most similar to the flawed reasoning in the passage.

Answer Choice A: This choice discusses the long-term effect of mercury on dolphins, but the observation period is only three months. This answer choice is correct because it also denies a causal relationship based on insufficient data, similar to the passage's argument.

Answer Choice B: This choice compares two potential causes (children's dreams and parental influence) and their effects on a child's career choice. This is not similar to the passage's argument, which is focused on ruling out a single cause.

Answer Choice C: This choice discusses two strategies for preventing cavities and tries to determine which is more effective. This is not similar to the passage's argument, which is focused on denying a causal relationship.

Answer Choice D: While the conclusion in this choice is worded similarly to the passage's conclusion, there are a few key differences. This choice switches terms from "average life span" to "good health" and relates the group to an average rather than a specific result. These differences make this choice not parallel to the passage's argument.

Answer Choice E: This choice compares the importance of knowledge of representatives' names versus command of political issues. The passage's argument does not involve a comparison of factors, so this choice is not parallel to the passage's argument.

In conclusion, the correct answer choice is (A) because it uses flawed reasoning most similar to the flawed reasoning in the passage. It denies a causal relationship based on insufficient data, just like the passage's argument.