Question

In a study of the effect of radiation from nuclear weapons plants on people living in areas near them, researchers compared death rates in the areas near the plants with death rates in areas that had no such plants. Finding no difference in these rates, the researchers concluded that radiation from the nuclear weapons plants poses no health hazards to people living near them. Which one of the following, if true, most seriously weakens the researchers' argument? (A) Nuclear power plants were not included in the study. (B) The areas studied had similar death rates before and after the nuclear weapons plants were built. (C) Exposure to nuclear radiation can cause many serious diseases that do not necessarily result in death. (D) Only a small number of areas have nuclear weapons plants. (E) The researchers did not study the possible health hazards of radiation on people who were employed at the nuclear weapons plants if those employees did not live in the study areas.

Short answer

Option C weakens the argument most.

Step-by-step solution

Identify the Conclusion

The conclusion of the researcher's argument is that radiation from nuclear weapons plants poses no health hazards to people living near them. This conclusion is based on the observation that there was no difference in death rates between areas near the plants and areas without them.

Assess Relevance of Options

Each option suggests a potential flaw or oversight in the study. The goal is to find the one that most seriously undermines the given conclusion that there are no health hazards due to radiation from the plants.

Evaluate Option C

Option C states that exposure to nuclear radiation can cause many serious diseases that do not necessarily result in death. This directly challenges the validity of equating the lack of difference in death rates with the absence of health hazards, highlighting that death isn't the only consequence of radiation exposure.

Consider Other Options

Evaluate the other options: - Option A is irrelevant because the study is about nuclear weapons plants, not power plants. - Option B mentions similar death rates but doesn't explain other potential health effects. - Option D might suggest the study sample was limited but doesn't directly address health hazards. - Option E focuses on employees not living in the study area, which doesn't directly affect residents.

Determine the Correct Answer

Option C most significantly weakens the argument because it indicates that health hazards could exist in forms other than death, such as non-fatal diseases caused by radiation, which the study failed to account for.

Key concepts

Argument Evaluation

In logical reasoning, evaluating an argument consists of carefully examining the various components that make it up. When you encounter an argument in an LSAT logical reasoning section, it usually consists of a premise and a conclusion. Sometimes, students find it challenging to separate these components. A premise is the evidence or the fact used to support the main claim, whereas the conclusion is what the author seeks to prove. To effectively evaluate an argument, you must:

• Identify the conclusion – What is the main point being made?
• Find the premises – What are the reasons provided to support the conclusion?
• Consider assumptions – What is taken for granted in the argument?

By evaluating these components, you'll be better prepared to analyze the soundness of an argument. This is crucial for LSAT's logical reasoning questions, as you need to identify whether the premises genuinely lead to the conclusion or if there's a gap in the logic.

Conclusion Analysis

Conclusion analysis involves a close examination of the argument's endpoint or main claim, which in this scenario, is that radiation poses no health hazards to nearby residents. It's essential to scrutinize how closely linked the conclusion is to its supporting evidence. A strong conclusion analysis checks if the conclusion logically follows from its premises. You must:

• Determine if any assumptions, regardless of being explicit or implicit, are necessary for the conclusion to hold true.
• Look for alternative explanations that could undermine the link between premises and conclusion.

In our given example, the conclusion drawn from similar death rates doesn't consider that health hazards could manifest in non-death-related illnesses. This oversight is precisely what option C highlights, showcasing a logic gap in the initial analysis.

Critical Reasoning

Critical reasoning is the practice of thoughtfully and rigorously examining the argument's logic. It involves questioning the reliability and completeness of the evidence supporting a claim. Particularly, for LSAT questions, this means understanding how arguments are constructed and where their weaknesses might lie. To engage in critical reasoning:

• Identify ambiguities and vagueness in the argument.
• Reflect on other pieces of evidence that, if true, could alter the argument's conclusion.
• Think about real-world implications and exceptions that may challenge the argument.

When critically reasoning through the example argument, you'd note that equating death rates with health hazards could overlook many nuances. Therefore, examining non-fatal effects, such as diseases that radiation exposure causes, becomes crucial for a well-rounded evaluation.

Weaken Argument Questions

Weaken argument questions on the LSAT test your ability to identify factors that could undermine an argument. Your task is to find a statement or piece of evidence that introduces doubt about the conclusion's validity. To answer these questions successfully:

• Consider the premises and find any assumption that, if negated, impacts the conclusion.
• Look for evidence that contradicts the premise-conclusion link.
• Identify external information that reveals oversight or error in the reasoning.

In the presented exercise, option C serves this purpose. By introducing the idea that radiation could cause serious but non-fatal diseases, it highlights a significant gap in the argument's basis, which solely focused on death rates as an indicator of health hazards. Thus, it effectively weakens the conclusion by uncovering the study's limited scope.