LSAT 106 | Section 2 | Logical Reasoning: Q22

LR Question 22 Explanation

QUESTION TEXT: Wirth: All efforts to identify a gene responsible for…

QUESTION TYPE: Main Conclusion

ARGUMENTS: Wirth argues that genes don’t cause manic-depression because no single gene causes manic-depression.

Chang agrees with Wirth’s evidence, but points out that there is evidence that several genes jointly cause manic depression.

ANALYSIS: Chang’s main point is that Wirth is using a restricted definition of “genetic cause.” Multiple genes could be the cause of something.

___________

1. CORRECT. Wirth assumes that only a single gene can act as a genetic cause. Chang points out that multiple genes can act together to cause something.
2. Chang says he agrees with Wirth’s evidence.
3. The genetics experts are definitely within their expertise.
4. Wirth never said that no evidence could prove him wrong. And Chang doesn’t accuse Wirth of saying that. Chang just adds new evidence that makes us re-evaluate Wirth’s conclusion.
5. Wirth doesn’t say his conclusion is 100% certain. He says it’s only true “if the researchers are right.”

Recap: The question begins with “Wirth: All efforts to identify a gene responsible for”. It is a Identify The Conclusion question. Learn more about LSAT Identify questions in our guide to LSAT Logical Reasoning question types.