LSAT Explanation PT 42, S2, Q14: In 1963, a young macaque monkey

LSAT Question Stem

Which one of the following is an assumption required by the argument above? 

Logical Reasoning Question Type

This is a Necessary Assumption question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

First, let's summarize and analyze the argument in the passage. The passage discusses a troop of macaque monkeys that began to enter a hot spring after one young monkey was observed venturing into it. This behavior was adopted by the entire troop over a few years. The author concludes that these macaques are able to adopt and pass on new patterns of social behavior, and are not complete captives of their genetic heritage.

The argument's structure is as follows:

Premise: Macaques adopted the behavior of entering the hot spring.

Conclusion: Macaques are not complete captives of their genetic heritage and can adopt and pass on new patterns of social behavior.

Now, let's come up with an "Evaluate" question: "Is the ability to adopt and pass on new patterns of social behavior in macaques solely a product of their genetic heritage?"

The question type for this problem is Necessary Assumption, and we are asked to identify an assumption required by the argument.

Answer Choices Explanation:

a) This answer choice suggests that the monkeys' behavior could be a product of genetic mutations. However, this supports the alternative cause for the behavior and contradicts the conclusion of the argument. Thus, this answer choice is incorrect.

b) This is the correct answer choice. It states that new patterns of behavior in macaque populations are not necessarily genetically predetermined. This assumption supports the argument's conclusion that macaques can adopt and pass on new patterns of social behavior without being solely determined by their genetic heritage.

c) This answer choice suggests that genetic alterations could be the cause of the new behavior becoming typical among the macaque monkeys. This supports the alternative cause for the behavior and contradicts the conclusion of the argument. Thus, this answer choice is incorrect.

d) This answer choice claims that the social behaviors of macaques are completely independent of their genetic heritage. While this statement would strengthen the conclusion, it is not necessary for the argument. The argument only needs to show that some social behaviors are not entirely dependent on genetics, not that they are completely independent. This answer choice is too strong for the Necessary Assumption question and is incorrect.

e) This answer choice discusses whether the new pattern of behavior will persist over several generations. However, this is irrelevant to the conclusion of the argument, which is about the ability of macaques to adopt and pass on new patterns of social behavior without being solely determined by their genetic heritage. This answer choice is incorrect.