12 Days of Christmas GMAT Competition - Day 5: Anthropologist: Finding

Manhattan Prep Official Explanation

Step 1: Identify the Question

The words most useful in evaluating in the question stem indicate that this is an Evaluate the Argument question.

Step 2: Deconstruct the Argument

An anthropologist notes that most people alive today find the sound of running water relaxing and that finding the sound of running water relaxing is heritable. She claims that early humans who lived near running water would have had significant advantages over humans that did not: Those people who settled near running water as a result of finding the sound relaxing would have had more offspring than early humans who did not find the sound of running water relaxing. Essentially, the author believes that some early people found the sound of running water relaxing, and so settled near it. Then, because running water provides significant advantages, these people had more offspring than people who were not relaxed by the sound of running water. As a result, most people today find the sound of running water relaxing.

Step 3: Pause and State the Goal

The author makes two major assumptions. First, the author assumes that early humans who were not relaxed by the sound of running water were less likely to settle there. If there were other reasons to settle near running water—such as being cleaner and safer to drink—humans might settle near it even if they didn’t find the sound relaxing. Second, the author assumes that finding the sound of running water relaxing wasn’t widespread amongst humans before some groups started to settle near sources of it. If most people already found the sound relaxing, it was merely survivor bias that resulted in the greater proliferation of groups that settled near running water. Both of these assumptions involve a correlation of finding the sound of running water relaxing and choosing to settle near it as a result.

Step 4: Work From Wrong to Right

(A) The argument makes it clear that early humans who settled near running water would have had significant advantages for survival and reproduction over those who did not. Perhaps some of those people found ways to mitigate, but not eliminate, those disadvantages. However, knowing that does not help evaluate any of the assumptions made by this author.

(B) CORRECT. The double negative wording in this choice is confusing. Start with the opposite: If early humans did avoid settling in places where they didn’t feel relaxed, the anthropologist’s argument would be strengthened. People who didn’t find the sound of water relaxing would settle elsewhere, and only those who found the sound of running water relaxing would reap the benefits of living near it. If, however, early people who were not relaxed by the sound of running water still settled near it anyway, then they would have gained the same benefits as did those who found the sound relaxing. In this case, the anthropologist’s argument would be weakened.

(C) Knowing by what percent these two groups differed does not address the author’s assumptions. For one, knowing that the difference in size between groups is, say, 10%, does not tell you which group is greater in number. And even knowing that the group that settled near running water was, indeed, greater in number would not help evaluate the argument that it was an affinity for the relaxing sound of running water that brought them there to begin with.

(D) The anthropologist makes it clear that humans who settled near running water would have had significant advantages for survival and reproduction over those who did not (i.e., those that lived near still or stagnant water or near no water at all). However, knowing the comparison of the number of offspring of those settling near still water and those settling near no water at all does not help determine whether the anthropologist's explanation for why most people find the sound of running water relaxing is valid.

(E) The anthropologist is not attempting to explain why people find the sound of water relaxing at all, but why most people do. This is a question of prevalence. Knowing the reason for the preference does not, on its own, help to explain whether the anthropologist’s explanation for the widespread occurrence of that preference is correct.