LSAT Logical Reasoning: Parallel Flaw Questions
A “parallel flaw” question is one that asks you to identify two argument that are flawed in the same manner as another argument. The question stem for a parallel flaw question might read:
- The questionable pattern of reasoning in which one of the following arguments is most similar to that in the argument above?
- The flawed reasoning exhibited by the argument above is most similar to the flawed reasoning in which of the following argument?
- Which of the following arguments contains flawed reasoning most similar to the argument above?
We solve these questions by following four steps:
- Identify the argument’s conclusion.
- Identify how the conclusion is supported.
- Identify how the argument is flawed
- Choose the answer that is flawed in the same way.
Let’s take a look at each step.
Identify the Conclusion
The main conclusion of the argument is supported by everything else in the argument; it’s what the rest of the argument is attempting to convince you is true. If you struggle with identifying conclusions, take a look at the Identify the Conclusion Questions lesson.
Identify How the Conclusion is Supported
Make a note of the premises. What supports the conclusion? Why does the author think we should believe the conclusion? Silently paraphrase the support to yourself, trying to understand why the author finds the premises to be so convincing.
Identify How the Argument is Flawed
These arguments are often flawed in obvious ways. Put the flaw into your own words, and consider writing down the flaw to the side of the argument to keep yourself focused as you work through the answer choices.
Choose the Answer
The correct answer will be flawed in the same way as the original argument. Note that it’s not enough for an answer choice to be flawed; it must be flawed in the right way.
A common trick for these questions is to include an answer choice that feels similar to the original argument but contains no flawed reasoning. These answers are tricky because we are drawn to the good logic. But our task in these questions is not to pick an answer with good logic; we must pick the answer choice with the same logical flaw as the original argument.