LSAT Explanation PT 37, S2, Q21: The studies showing that increased consumption

LSAT Question Stem

The pattern of flawed reasoning in which one of the following is most similar to the pattern of 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 A. 

LSAT Question Complete Explanation

The argument in the passage states that studies show increased consumption of fruits and vegetables may help decrease the incidence of some types of cancer, but these studies do not distinguish between organically grown and nonorganically grown produce. The author then concludes that there is no increased health risk associated with eating fruits and vegetables containing pesticide residues. The structure of the argument is as follows:

Premise: Studies show that eating fruits and vegetables is healthy, and there were a few vegetables here and there that were not organic.

Conclusion: This proves that organic and inorganic are equally healthy.

The flaw in the argument is that the author has referenced instances of benefit from a mix of two things (organic and nonorganic produce) and then concludes that the two are equivalent in terms of health risk.

An "Evaluate" question for this argument would be: "Do the studies account for the potential long-term effects of consuming pesticide residues on health?"

Now let's analyze the answer choices for the Parallel Flaw question:

a) This answer choice is correct. The author discusses an instance of benefit from power plants, nuclear and non-nuclear, and then concludes the two types to be equivalent in safety. This flaw is parallel to the one in the passage.

b) The flaw here is that there is no way to assess or compare the effectiveness of dietary restriction based on the information provided. This is not the same type of flaw as found in the passage, so this answer choice is incorrect.

c) The problem with the reasoning in this choice is that the author makes an apples-to-oranges comparison—between motorcyclists with a year of training and car drivers with almost no training. Although this author's conclusion is not valid, this does not represent the same type of flaw as that in the passage author's argument.

d) This argument draws an overly broad conclusion—that there is no difference in risk of using wood vs. plastic—without any information about the various microbes that may attack the different types of cutting boards. This is flawed but different from what we're looking for, so this answer choice is incorrect.

e) This argument does not parallel the reasoning found in the passage. This argument is as follows:

Premise: Health-wise, vitamins are equivalent to a small increase in fruits and vegetables.

Conclusion: Thus, there is no health risk in not taking vitamins as long as one is getting enough fruits and vegetables. Since this conclusion is valid, this answer choice cannot be correct.

In conclusion, the correct answer choice for this Parallel Flaw question is (a), as it demonstrates the same type of flawed reasoning found in the passage.