Logical reasoning PrepTest 127 · Section 3 · Question 22

Incorrect. The double negative in this answer makes it very difficult to analyze, so let's rephrase it to eliminate that. If two species don't belong to the same species, then they belong to different species. So this answer states: Morphological differences don't guarantee two groups are different species. And that's in agreement with the author's argument—Neanderthals and Cro-Magnons have morphological differences but are probably members of the same species. This answer is supported by the stimulus, not contradicted by it.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Cannot Be True

Stimulus Summary:
Some scientists: Neanderthals and Cro-Magnons had minor morphological differences, so they were different species.

Author:
(1) Neanderthals/Cro-Magnons difference - They lived in different places
(2) Neanderthals/Cro-Magnons similarity - Exact same tools; Similar behavior
(3) Similar tools → Faced same daily challenges AND Met them in same way
(4) They were probably members of the same species
(5) Any morphological differences were just a result of the different places they lived

Answer Anticipation:
That is a lot of information, a lot of complicated language, and a lot of details that it feels like we'll need to keep track of. However, there are some things we can do to make this easier on ourselves.

First, we can anticipate that the opposing point—the view of some scientists that these two groups were different species—won't play a role in the answer. The author believes that they're wrong, and so any relevant information brought up in that argument is referenced in the author's.

Second, we can focus on elements we know to be important—comparisons, and conditional statements. In particular, Cannot Be True questions that feature conditional language tend to have answers that violate that conditional.

Here, the stimulus establishes that two groups would use similar tools "only if" they faced the same daily challenges and met those challenges in the same way. To violate a conditional, we find an answer that establishes the sufficient without the necessary condition. Here, that would mean finding two groups with similar tools who didn't face the same daily challenges or didn't meet them in the same way.

And while this might be enough to find the answer, we can actually go a step further because we're told about two groups that do have the exact same tools—Neanderthals and Cro-Magnons. Based on that, we can conclude that they faced the same daily challenges and met them in the same way. Any answer suggesting otherwise also cannot be true.

Let's head to the answers now with these anticipations.

Answer Explanation:
This answer has to deal with the conditional statement, so we should see if it contradicts it. We know that the Cro-Magnons and Neanderthals faced the same daily challenges—the conditional guarantees that based on them using the exact same tools. We also know that they lived in "different environments." Therefore, this answer cannot be true—the environments that the Neanderthals and Cro-Magnons lived in were different from each other, but the daily challenges they presented to their inhabitants were the same, so those challenges can't be unique to an environment.

Key Takeaway:
When you're in a Cannot Be True question with a ton of details and information, focus on elements that are likely to be contradicted. In particular, conditional statements tend to serve as the basis for things that you know must be true, so anything that contradicts that cannot be true.

Incorrect. The stimulus does note that Cro-Magnons were the forerunners of modern humans, but it never discusses our morphological features, or how similar they are to Cro-Magnons. Since we don't have information about this answer, it could be true for all we know and is thus incorrect.

Incorrect. The author uses the similar tools to support a conclusion that these two groups were the same species, but that treats the similar tools as sufficient to prove this, not necessary. So this answer isn't supported, but a conditional relationship doesn't contradict the reverse relationship. Illegal reversals/negations are invalid inferences, not things that must be false, so we can eliminate this answer. (In other words, a conditional doesn't guarantee the reversal is true, but that reversal might be true.)

Incorrect. The stimulus notes that the two groups lived in different environments, so that aligns with this answer.