Q23 - Some statisticians claim that the

[gregory.mortenson]

Question: argument is most vulnerable to criticism

The argument starts with "correctness" as its premise but then bases its conclusion off of "survival".

I found A very tempting, but doesn't it say the opposite of the argument? I thought the argument was saying Statisticians must be mistaken in their claim to increase correctness because if they were correct it would hinder one's ability to survive. Answer A says that correctness would NOT hinder survival. What am I missing here?

[aileenann]

I don't think (A) says the opposite of the argument. Rather (A) claims the statisticians must be incorrect mainly because their theory would lead to less survival. However, this rests on the claim that survival has something to do with the best of improving one's beliefs, automatically assuming that correctness of beliefs should not conflict with survival - an assumption made explicit in (A). Basically (A) says the argument is flawed because it presumes this thing that isn't necessarily true.

Let me know if that helps or if you would like further clarification.

[gregory.mortenson]

That helps... I got tangled up in the wordiness of answer choice A. Even so, working backwards it's easy to see why the other 4 are clearly wrong!

[geverett]

This question was a mouthful. I'll do a play by play on it to break it down for anyone that might have had a tough time with it.

Sentence 1: Some statisticians believe that the best way to increase the percentage of correct beliefs out of all the beliefs a person has is this way: Never change your set of beliefs except by rejecting a belief that has been shown to be false.

Sentence 2: If this were the only rule somebody followed in regards to increasing the correctness of beliefs then anytime a person was presented with new information there would be only two options that person would have: 1. reject a belief or 2. Leave beliefs unchanged.

Sentence 3: If someone followed this logic then as time passed that person would have fewer and fewer beliefs.

Sentence 4: Survival requires many beliefs so this rule is wrong.

Initial thoughts: Okay so the argument starts out by citing a claim that some statisticians hold to be true. The author then infers from this claim that anybody who believes the statisticians claim would be forced to make two choices if presented with new information. The author then draws a sub-conclusion in the 3rd sentence that a person would inevitably have fewer beliefs over time by following this rule. The author then draws the main conclusion in the last sentence that the statisticians claim is false since survival requires many beliefs.

There are a couple assumptions worth noting here. 1. The author assumes that a person could not choose option #2 (leaving ones beliefs unchanged) indefinitely. If that were the case then one would not necessarily have fewer and fewer beliefs as their belief set would remain unchanged indefinitely.
2. The author assumes that the truth of the statisticians claim requires a person to be able to maintain survival, but the statisticians claim in sentence 1 mentions nothing about survival. It only talks about increasing the correctness of one's beliefs. Whether or not someone lives longer or dies earlier by following the statisticians claim is not mentioned at all in the statisticians claim. It's quite possible that something which ensures an increase in the total correctness of one's beliefs could also be something which ensures the quickest way to die. We could not conclude from this that the thing which ensures an increase in the total correctness of one's beliefs is therefore false. Think about it and let me know if this point needs any further clarification.

I go to the answer choices with this in mind.

(A) This is exactly what the second assumption I pointed out in my prephrase addressed. If you need any further clarification feel free to ask.
(B) The statistician gave us one criteria for increasing the overall correctness of one's set of beliefs: never change that set except by rejecting a believe you have been given adequate evidence against. This is the only rule cited in the statisticians rule. Answer choice B is trying to add an additional rule to the statisticians way of increasing the overall correctness of one's beliefs. This is not allowed according to what we have been given in the sentence. Get rid of it.
(C) This is not a flaw. This argument has nothing to do with a comparison of large sets of beliefs vs. smaller sets of beliefs. It's about rejecting the statisticians rule based on a necessary condition the author has added in the conclusion: "survival." Get rid of it.
(D) While one could argue that he states this explicitly one could also make the argument that he does not necessarily advocate accepting any beliefs. He only advocates rejecting a belief: the statisticians belief. Get rid of this answer choice.
(E) The author does not conclude that the "many beliefs" we have must be "correct beliefs". Revisit the exact phrasing of the last sentence/conclusion if there is any confusion on this point.

Hope this helps. This isn't an easy question and I would definitely welcome any further clarification/disagreement on any of the points I made.

[LSAT-Chang]

Hello geverett, I actually picked (B) for this one and I eliminated (A) immediately when I saw it.. I'll try my best to explain my thought process.

So first off, yeah this was not a fun argument. It seemed like there was a lot of stuff going on and I was lost in the middle trying to search for the conclusion, until I finally found that the last sentence was the actual conclusion. So the reason I picked (B) was because the author is saying that over time, one could ONLy have fewer and fewer beliefs. But like you addressed in your first point, if we don't reject any beliefs, and indefinitely leave the belief's unchanged, then we wouldn't have fewer and fewer beliefs, right? So I thought that was what (B) was getting at -- since in the second sentence, the author says "However, if this were the ONLY RULE one followed blah blah", but what if it WEREN'T the only rule followed? If (B) were true, then we could have the statistician's rule and also we could accept new beliefs when presented with some kinds of evidence so in the end, we WON'T have fewer beliefs! In fact, couldn't we even have more since we would be accepting new beliefs??

Okay I may be just rambling about the wrong parts that I shouldn't be focusing on -- I'm just plainly lost and I thought that (B) was getting at what I was thinking but I guess not.. but I don't know why. I think I'm focusing on all over the argument and not IDing on the core -- because it was so hard to get the simple core for this problem. Could you explain (B) as well as (A) a little further? And a touch on the actual core for this problem would be very helpful as well.

[timmydoeslsat]

I remember a similar question on the LSAT that involved this same kind of reasoning flaw. "But if that were true, humans would not survive! Therefore it has to be false!"

Just because something means the end for humans DOES NOT mean that it is false. It is time for humans to take the harsh dose of reality!

This argument can be seen like this:

Some statisticians claim...(you know the author is probably going to disagree with this! Classic LSAT structure) that the surest way to increase the overall correctness of the total set of one's beliefs is to do this:

The only way you can change your set of beliefs is to reject a belief when sufficient evidence is against that belief.

So notice that these statisticians have precluded the idea of adding to your beliefs. That is something that is not in line with this way of increase correctness according to these statisticians.

Notice that (B) says even when following the rule, one might also accept new beliefs. You cannot do this! If you accept new beliefs, you are NOT following the rule.

The argument concludes that this claim of how to increase the correctness must be mistaken because humans need many beliefs to survive and this claim can only give a human fewer and fewer beliefs.


Think of an analogous argument:

Some trainers claim that the surest way to increase your 40 yard dash time is to slap a lion and then run away while while leaping hurdles set out across a desert that spans 500 miles without water or rest. However, nobody could do this. Therefore, the trainers' claim is mistaken.


It does not have to be mistaken! Perhaps that is the surest way. Just because people cannot do it, or even survive doing it, does not mean that this is not the surest way of increasing something.

[LSAT-Chang]

Think of an analogous argument:

Some trainers claim that the surest way to increase your 40 yard dash time is to slap a lion and then run away while while leaping hurdles set out across a desert that spans 500 miles without water or rest. However, nobody could do this. Therefore, the trainers' claim is mistaken.


It does not have to be mistaken! Perhaps that is the surest way. Just because people cannot do it, or even survive doing it, does not mean that this is not the surest way of increasing something.

Hahaha you made me laugh. That is one fun analogy. Not only fun but I definitely see the flaw in this argument now.!!!

[bbirdwell]

Nice. I've always wanted to be faster. Maybe I'll do that, starting with something smaller than a lion... like a dachsund.

Keep having fun with this stuff! I think it's the real key to mastery of this test...

[randitect]

I chose E and I'm still unsure as to why it's incorrect (though I see the logic behind A). Could someone please explain why E is wrong?
Thank you.

[Nina]

Thanks for so many nice explanations. I think I well understand why A is correct, but still think E has some reason to be correct.
although "we need many beliefs in order to survive", if we do not need correct beliefs to survive, then we don't even need to follow the rule that leads to the decrease of our beliefs. Maybe I was misunderstanding, but the way the last sentence stated is a little bit ambiguous. at least in order to indicate we are following the rule, it should be stated as "since we need many correct beliefs in order to survive"...

am I wrong about this?

Many thanks!

[griffin3575]

I think this question can be solved very easily if we just zero in on the core:

Over time, beliefs will decline
+ -------> Claim is false.
We need many beliefs to
survive

Where did survival come from? And why does preventing survival lead to a mistaken claim?
Hmm. Lets look at this more closely. Living by this claim inhibits us from surviving, thus the claim is false. More simply, NO survival, NO claim....

Wait a second, doesn't this look a lot like conditional logic? The author denies one thing, then concludes another thing cannot happen. Perhaps something like:

~Survival ---> ~Claim
or
Claim ---> Survival

Aha! Here is the key assumption! The author is assuming that in order for the claim to be valid, the claim cannot inhibit our ability to survive. Survival is necessary for the claim to be substantiated. This is best expressed in answer choice A.

**As a side note, the element of survival in the last sentence comes out of no where. This should be a red flag that the correct answer is going to somehow connect survival to the statistician's claim. Choice A is the only answer choice that mentions survival. Additionally, I also agree with the above poster that another assumption the author is making is that a person cannot indefinitely leave one's beliefs unchanged. This was the assumption that jumped out at me as I read this question, and I immediately ran to the answer choices searching for it only to waste 2 and a half minutes looking for a nonexistent answer choice. Lesson learned - always keep an open mind!**

[sportsfan8491]

I think the major problem with answer choice (E) is that the author does not assume that in order for us to have "some/many" beliefs, it is necessary for these beliefs to ALL be "correct beliefs". I think it is perfectly consistent with the author's argument that some of the beliefs could actually be "incorrect beliefs", in order for us to still have "some legitimate according to the stimulus" beliefs.

Some people might think that the author assumes that all of our beliefs must only be correct beliefs, but this is not in fact what he says. I believe the important thing you need to do is realize that there is a clear distinction that needs to be drawn between the "correct beliefs" we get in answer choice (E) and the "overall correctness of a set of beliefs" we are given in first sentence of the stimulus. They are two different concepts. Otherwise, you might unconsciously commit a part-to-whole error in reasoning by thinking that "correct beliefs" is actually something the author relates to or discusses in the stimulus, which I do not think he does.

So, if you did what I mentioned above, you might assume that the author is taking for granted (i.e. assuming) that beliefs can ONLY be correct beliefs. However, we are not presented with any semblance of the "correct beliefs" idea in the stimulus. Why? Because, if we were to follow the principle cited, we may actually be led to reject a correct belief and keep an incorrect belief because there is not "enough adequate evidence against it" (didn't many astronomers and scientists believe that the other planets and the Sun revolved around the Earth at one point, before Galileo championed heliocentrism?). Then all of our beliefs might not be correct, but they would still be legitimate beliefs according to the criteria we get in the stimulus. Please re-read the first sentence 3 or 4 times if you don't see what I mean.

So, this answer is wrong because the author doesn't assume that for someone to have some beliefs, those beliefs must only be correct. It also appears the author assumes that people could have some "legitimate beliefs" even if those beliefs were incorrect. In other words, that person could, according to the stimulus, still have "legitimate" but "incorrect beliefs", and the overall correctness of their total set of beliefs might still increase (so long as it leaves unchanged or improves their chances of survival).

I hope this makes sense. It is a pretty confusing concept and a great trap answer choice for the final answer on this question.

[ohthatpatrick]

Let me briefly follow up on (E) by reminding everyone that one of the most popular trap answers on Flaw questions is

takes for granted + EXTREME
presumes w/o justification + EXTREME

Remember, those two phrases mean the same thing as 'Assumes', as in Necessary Assumption. And remember, on Necessary Assumption questions (and on Flaw answer choices that begin with some paraphrase of 'assumes'), we should beware strong language.

The line that (E) comes closest to referencing is "we need many beliefs in order to survive".

Does that claim entail that ALL beliefs we have are correct ones? No.

Is the author fighting with the statisticians because they're claiming we're allowed to have incorrect beliefs, but the author thinks we need all correct beliefs?
No.

The author is fighting with the statisticians because they're advocating trimming away incorrect beliefs, leaving us with fewer and fewer over time, but the author thinks we need many to survive. The author's point of concern is the QUANTITY of beliefs we have, not the 100% accuracy of those beliefs.

If anything, the author is actually arguing the opposite of what (E) is saying.

The statisticians are talking about us weeding out our incorrect beliefs, so that the remaining ones are more overall correct.

The author is pushing back AGAINST that idea ... he's fighting the strategy of weeding out the incorrect beliefs, because his concern is that we still have enough beliefs. So the author seems to be okay with holding onto some incorrect beliefs for the sake of retaining the "many beliefs we need in order to survive".

Hope this helps.

[T.J.]

Looking back, this question is ridiculous. And the reason why I did it wrong is because i had a narrow vision. I was trapped in the argument, thinking that we have to survive and if so, the statistician must be wrong.
Well, how would a legit argument look like if you want to reach the same conclusion. I would say something like even if you follow the statistician's advice, it's possible that the correctness of your beliefs would not increase. Maybe I don't have any correct ones in the first place. By the same token, this is why (D) is wrong, cause it's sidestepping the issue.

[WaltGrace1983]

Geeks,
As some others have mentioned, I feel that there are a few other jumps being made here.

(1) Assumes that this would be the only rule followed
(2) Assumes that, if given the choice between rejecting beliefs or leaving beliefs unchanged, there will definitely be some instances of the latter.

Would it be terribly un-LSAT-like to work with these assumptions, given that the other assumption (about survival) is so painfully obvious? When you did this problem the first time, did you even waste time worrying about these two other assumptions?

[ohthatpatrick]

I don't think it's fair to say that your 1st assumption is an assumption. The author says "if this were the only rule one followed ..."

So that's explicitly given.

I definitely agree with the 2nd one: it is a given from the logic that our number of beliefs could only decrease, but it is possible they could stay the same as long as every new piece of evidence did not provide adequate evidence against any beliefs.

I did NOT consider that line of arguing just because the survival claim seemed to come out of nowhere (and thus seemed like the appropriate target of criticism), but you definitely COULD have had a legitimate answer such as "takes for granted that over time at least some new evidence would provide adequate evidence against some of our beliefs".

However, it's such a common LSAT pattern that when person B disagrees with person A's claim, the reason person B offers is a bad rebuttal, completely compatible with person A's claim. So when I saw, "Nuh-uh, because you need many beliefs to survive", I just looked for something addressing the bad, irrelevant rebuttal.

(I would add another line of objection/assumption while we're playing this game: we need "many" beliefs in order to survive ... well what is "many"? how many beliefs do we begin with? if we start with 100,000 beliefs and over time whittle it down to 20,000 beliefs, don't we still have many beliefs? Is that enough to survive? All these questions factor into the actual math of when a diminished set of beliefs would start to threaten survival)

[xsksquid]

Thanks for the excellent explanations! I have one more question for (A). I eliminated this choice because of the word "hinder"--I thought the word isn't strict enough. According to the argument core ("in order to survive"), the author is only presuming that "the surest way must not PREVENT one's ability to survive"; he didn't necessarily assume that the surest way must not DIMINISH/HINDER one's ability to survive.

I chose B originally. I understand it is wrong because the statisticians' claim has already ruled out the possibility of "accepting new beliefs". However, the wording "hinder" in A still bothers me.

Could anyone from the Manhattan Prep address my question please? Thank you.

[emily315]

I also got it wrong and trapped in the wrong pattern of thought of info never mentioned by author that all beliefs we need to survive must be true.
Here is a little diagramming that helped me to understand:
1. increase correctness--> reject wrong--> less claim
2. survive-->many claim

logic: survive-->many claim--> -[less claim]--> -[reject wrong]->-[increase correctness]

in translation, basically, the author is saying in order to survive, we need many claims, so we can't have less and less claims over time, so we can't reject claims when we find out they are wrong, which ultimately results in the logic end of we can't increase the overall correctness of one's belief.
But where does the the jump from 1->2 happened. That's the logic flaw here. Bingo~
hope it helps

[DPCTE4325]

I don't think it's fair to say that your 1st assumption is an assumption. The author says "if this were the only rule one followed ..."

So that's explicitly given.

I definitely agree with the 2nd one: it is a given from the logic that our number of beliefs could only decrease, but it is possible they could stay the same as long as every new piece of evidence did not provide adequate evidence against any beliefs.

I did NOT consider that line of arguing just because the survival claim seemed to come out of nowhere (and thus seemed like the appropriate target of criticism), but you definitely COULD have had a legitimate answer such as "takes for granted that over time at least some new evidence would provide adequate evidence against some of our beliefs".

However, it's such a common LSAT pattern that when person B disagrees with person A's claim, the reason person B offers is a bad rebuttal, completely compatible with person A's claim. So when I saw, "Nuh-uh, because you need many beliefs to survive", I just looked for something addressing the bad, irrelevant rebuttal.

(I would add another line of objection/assumption while we're playing this game: we need "many" beliefs in order to survive ... well what is "many"? how many beliefs do we begin with? if we start with 100,000 beliefs and over time whittle it down to 20,000 beliefs, don't we still have many beliefs? Is that enough to survive? All these questions factor into the actual math of when a diminished set of beliefs would start to threaten survival)

Hi Patrick,

Can you please show us how you'd approach this question by arguing for the anti-conclusion? I didn't choose A because my prephrase was "Okay, even if we need many beliefs in order to survive, and even though when one is presented with evidence, one would have to reject some of the beliefs or leave beliefs unchanged.... STILL the statistician's claim is CORRECT"

And using this method I landed on C. Can you show me how I should have adjusted my prephrase for the anti conclusion?

[ohthatpatrick]

Sure thing. I don't try to pre-load all that stuff right away (especially with an argument this long).

I just initially see the CONC is "the statisticians' claim is wrong" and think,
"Okay, I'm arguing that their claim is true".

What's their claim?
"the surest way to increase the overall correctness of your belief set is to never risk adding new beliefs and to jettison any belief when you find out it's false".

Suppose you had a laundry bag full of change and you wanted it to be nothing but pennies. This advice is saying, "Don't add any more change to the bag. And every time you reach in and pull out something that isn't a penny, toss it away; do not return it to the bag."

That sounds pretty legit to me! I don't know whether it's the "SUREST" way to increase you beliefs, but it would certainly work.

What is the author's reason for thinking it wouldn't work / isn't the surest method?

She says that over time we'd have fewer beliefs, and we need many beliefs in order to survive.

Well, say we start with 1000 beliefs and we need 100 of them in order to survive.
As we filter out the false-beliefs over time, we won't necessarily ever hit the dead-threshold of 100 beliefs. And along the way, with each false-belief we get rid of, the overall correctness of set of beliefs keeps increasing.

Maybe there's a huge cushion between the number of beliefs we start out with and the number of ones we need to retain for survival!

That's probably the sort of objection I would conjure up before looking at the answers. It's possible I might have the reaction of, "Hey, author, who cares if this is FEASIBLE / DAMAGING? This is just statisticians talking about whether a mathematical principle would hold."

But I might not. When I see (A), I would ask myself "DID the author assume that the surest way shouldn't hinder survival?" And I would keep that answer, mostly because the author IS rejecting 'the surest way' on the basis of 'how it would affect our survival'.

(C) is comparing one person's set of beliefs to another's. The statisticians' claim didn't have anything to do with ranking the correctness of YOUR beliefs to that of MINE.

It was all about increasing the correctness of YOUR beliefs: comparing how correct YOUR beliefs were previously to how correct they are later, if following this plan that's laid out.

Also, this sounds more like an objection to the statisticians. The author's premise is about survival, so if our objection is addressing the concern about survival, it feels off topic.

Hope this helps.