#14 - Scientist: A controversy in paleontology centers on

[Administrator]

Complete Question Explanation

Weaken. The correct answer choice is (B)

Here again we have a familiar stimulus format: a question is presented, and a conclusion is drawn by the scientist. The question: Which came first for early humans, sophisticated tools or standing upright?

• Premise: Advanced toolmaking requires free use of the hands.
  
  Conclusion: Standing upright came first (this is the scientist’s conclusion)

Answer choice (B): This is the correct answer choice. Again, this straightforward weaken question will provide only one answer choice that will weaken the scientist’s conclusion. In this case, that answer choice is (B), which suggests that pre-walking humans may have had advanced hunting weapons. This weakens the argument in two ways: The premise is weakened, because this new evidence seems to show that constantly free hands were not necessary, and of course the conclusion is weakened, because this answer choice suggests that sophisticated tools actually may have come first.

Answer choice (A) doesn’t weaken the argument, as the scientist’s focus is on advanced tools.

Answer choice (C) strengthens the scientist’s assertion that standing upright came first.

Answer choice (D) effectively attacks the sole premise in the stimulus, and answer choice (E) is irrelevant (but possibly tricky): The scientist’s premise is that the tool makers needed to be able to stand upright (not the tool users, as discussed in this incorrect answer choice).

[jared.xu]

Is this a problem that you could only solve by process of elimination? I got it right by eliminating the wrong answer choices, but it cost a lot of time because the right answer had a few holes in it. The right answer B states: "Advanced hunting weapons have been discovered among the artifacts belonging to prehistoric human ancestors who did not stand upright." I couldn't choose this answer until I made sure all the other answers were wrong. The reason I hesitated was because the scientist could easily argue: "what if they merely stole the weapons from the prehistoric humans who did stand upright and who were making the tools with free hands?" There is also a doubt in my mind whether advanced hunting weapons could fit under the category of "sophisticated tools" or not. Is it true that B is right only if we make a lot of assumptions, such as the prehistoric human ancestors who did not stand upright did indeed make the advanced hunting weapons? Is it right to say that some right answers are right only if we make additional assumptions to fill in its gaps? Thank you.

[Eric Ockert]

Jared

Keep in mind that your job in Weaken questions such as this is merely to call the argument into question, you do not need to Disprove it. In many cases, the author could very easily counter the correct answer with additional info. But that would not change the fact that, if this fact were true, the author would have a problem.

In this case, if you've found these weapons among those who did not stand upright, the Scientist has a problem with his conclusion. It is certainly less likely that humans had to have stood upright first, as you have an apparent counterexample here of a group who didn't stand upright, yet had these advanced tools. If this were the real world, he absolutely could counter with the explanation that you suggested. But the fact that he would be forced to counter, indicates his argument has been called into question in the first place.....which is exactly the goal you are trying to accomplish here.

Hope that helps!

[eyeofthetiger]

Hi team,

Your counter to Jared's reasoning makes sense to me. However, I narrowed my Contenders to (B) and (E), and am having trouble ruling out E. Since this is a Weaken, I want to question the Scientist's argument (combo of premises and conclusion), and his argument is essentially:

standing upright frees the hands, which consequently makes advanced toolmaking possible, which tells us that humans stood upright before they developed these tools.

I understand why (B) is correct, but can't see why (E) isn't just as good. For example, if early tools didn't require their users to stand upright, then isn't the argument weakened? If tools are made to be used NOT by the hands, then doesn't that mean that it isn't necessarily true that the humans stood upright before developing them? OR, are the LSAT makers choosing words to wisely for me, ie, a non-hand "user" of a tool has nothing to do with a "maker" or "developer" of a tool?

Thanks as always

[Emily Haney-Caron]

Hello!

Great question, which you correctly answered yourself! Here, there is a difference between whether you need free hands to MAKE a tool vs. whether you need free hands to USE a tool, and that distinction is why E is not the best answer.

[Blueballoon5%]

5. Scientist: A controversy...

Which one of the following statements, if true, most weakens the scientist's argument?

C) Many prehistoric human...


My Question: The answer explanation in the student online center states that answer C is wrong because "it strengthens the scientist's assertion that standing upright came first." I do not see how C would strengthen the stimulus.

[Steve Stein]

Hey Blue Balloon,

That's a good question. If advanced tool-making had preceded standing upright, we might expect to see ancestors who could not yet stand upright but already had sophisticated tools. Instead, we see ancestors who were already able to stand upright, but had not yet developed abilities in advanced toolmaking, suggesting that standing upright preceded the development of that skill.

I hope that's helpful! please let me know whether this is clear--thanks!

~Steve

[Blueballoon5%]

Thank you! Yes, this makes it clear!

[cindyhylee87]

Hi,

I am not sure why answer (D) could not weaken the scientist's conclusion if those prehistoric human who first came to stand upright had as much dexterity as those who did not stand upright. It seems to me that since standing upright cannot guarantee advanced toolmaking skills to be developed, it would possibly weaken the scientist's argument.

Thanks,
Cindy

[Jonathan Evans]

Hi, Cindy,

Good question! This is a pretty fun Weaken scenario in that it deals with pretty cut and dried conditional reasoning. In other words, we have premises that contain a condition necessary for a corresponding sufficient condition. Then, in the conclusion, the author makes a Mistaken Reversal™ error.

Let's take a look at this argument's structure. First the premises:

1. Advanced Toolmaking Free Use of Hands
2. Standing Upright Free Use of Hands

Now the conclusion:

• They must have stood upright first.

Let's follow the chain in the reasoning here. On the left side of the arrows in the premises, we have the sufficient conditions. On the right side of the arrows, we have the necessary conditions.

The author seems to think:

• Advanced Toolmaking Free Use of Hands Standing Upright

In other words, the author seems to believe that Advanced Toolmaking requires Standing Upright. This doesn't work. Looking back at statements (1) and (2) above from the premises, there is in fact no conditional chain we can make. Advanced Toolmaking requires Free Use of Hands, and Standing Upright also "requires" Free Use of Hands. Standing Upright is a sufficient condition for Free Use of Hands. If you're standing upright, you must have free use of your hands.

Thus, there's no chain here connecting Advanced Toolmaking and Standing Upright. There is nothing in the premises that says that you can't have Free Use of Hands without Standing Upright. There could be some other way to have Free Use of Hands! For example, what if just "sitting upright" permitted free use of hands?

This is why Answer Choice (B) works. It takes advantage of the fact that the whole (2) Standing Upright Free Use of Hands relationship is extraneous! It's still conceivable that we have advanced tools in populations that did not stand upright. There's no evidence to the contrary.

Now to Answer Choice (D). What if the upright people had no more dexterity than the non-upright people? You're right. You could conceivably argue that this lack of difference in dexterity might show that the new population should have no apparent advantage in toolmaking over the old one. However, this scenario has a few problems. First, it fails to address the most glaring flaw in the author's reasoning, that is the Mistaken Reversal™ conditional flaw. Second, it brings in a tertiary consideration, the idea of dexterity, a concept which is out of the scope of the argument. To some extent, you must bring in some additional assumptions to make it work. Lastly, this answer choice is not the one that "most weakens" the scientist's argument. In these weaken questions, we're talking about a question of degree. Which is the best answer, or which does the best job accomplishing the task? In this case, (B) weakens the argument more.

Thanks for the great question. I hope this helps!