Q5 - Area resident: Childhood lead poisoning

[ohthatpatrick]

What does the Question Stem tell us?
Flaw

Break down the Stimulus:
Conclusion: If we get rid of lead paint in homes that still have it, there will be no more childhood lead poisoning.
Evidence: Childhood lead poisoning has declined as we have phased out leaded gas and lead paint. But 25% of homes still have lead paint.

Any prephrase?
Our job is to debate the prediction, so we have to pose this question: "If we eliminate lead paint in the remaining homes that have it, how could childhood lead poisoning STILL sometimes happen?" Would there still be lead paint in other buildings besides homes? Maybe offices / schools / shopping malls? In order for childrren to get this lead poisoning, we'd need there to still be some source of lead they're exposed to. We could say the author assumes "If it's out of homes, then children are no longer in risk of exposure".

Correct answer:
C

Answer choice analysis:
A) Bad move -- did the author rely on statistics that were portrayed as potentially unreliable? No, the stats seem reliable. There's no text allowing us to reach the paranoid conclusion that the stas are sketchy.

B) Classic circular reasoning flaw (almost always wrong). Are the conclusion and premise nearly identical? Heavens no.

C) Objection answer -- if there are other significant sources of lead in the environment, would that weaken the argument? Definitely!

D) Assumption answer -- does the author need to assume it will be cheap to eliminate the lead paint? Nope. Even if it's expensive, his conclusion could still work. His claim is not that we SHOULD eliminate the paint or even COULD. It's just a claim that IF we did, we would see effect X (no more childhood lead poisoning)

E) Assumption answer -- does the author need to assume ALL of the leaded-homes (the 25%) have children in them? Of course not. Too extreme.

Takeaway/Pattern: Here the author is making a Prediction. Many predictions take the form of, "If X happens, Y will happen." You're never arguing with whether or not X will or should happen. You're only evaluating whether X guarantees Y. You debate it by thinking through a world in which X happens, but Y does NOT happen. The other layer to this story is the Solution to a Problem archetype. The author thinks we have a perfect solution. Typical pressure points are (Only a partial solution, which is what C is getting at .... or the solution Backfires in some unanticipated way)

#officialexplanation

[panman36]

Can somebody try to tell me what the heck wrong answer choice "B" means? I almost chose it because I thought it meant something like "relies on an assumption that is necessary for the conclusion to be true." In which case the assumption could be that there are no other significant sources of lead in the area's environment, and "B" would be correct.

However, now I realize this is not what it means. I'm guessing this is a fancy way of describing circular reasoning? I can't remember seeing it written this way before. It would be good to know for sure in case this ever comes up again

[aileenann]

Your second thought is correct - this is another way of describing circular reasoning, which by definition is assuming the conclusion to get to the conclusion. This argument doesn't do that. Nice work!

[genieb]

I chose the correct answer C. But I also thought E was plausible- If it is not true that "children reside in all of the homes in the area that contain lead paint", then wouldn't that hurt the argument that "childhood lead poisoning in the area will finally be eradicated?"

Because if there are no children in those homes in the first place, then how would childhood lead poisoning even be a concern? (Okay now I can see that it can be a strengthener of the argument...because if no children --> no poisoning --> problem eradicated --> conclusion supported hence not a flaw!)

Why does my brain play tricks with me?

Somebody please tell me why E is wrong so I can be 100% convinced. Thanks!

[timmydoeslsat]

We have to remember this is a flaw question stem.

We read that lead paint is still found in 25% of the area homes. And we say that if this is eliminated, childhood lead poisoning will be finished.

With such a strong conclusion, the argument has to presume that no other significant sources of lead are out there.

Answer choice E is much too strong. Does the author presume that children live in every single house affected with lead poisoning? No. You could have 30 children total, have them live in lead paint homes, but also have 500 other people living in lead paint homes with no children present.

If you are ever unsure of how an answer choice like this works in the context of the argument, you can negate the answer choice. You can do this with answer choices that start off with "presumes, assumes, takes for granted, etc. It is a necessary assumption with language like that. So if you negate E, it becomes that children do not live in all of the lead paint homes, the argument is left unaffected. So this was not an assumption of the argument.

[nicole.e.carter]

Could someone give a more detailed takedown of (b)? I sometimes get thrown by jargon-y answer choices like that one. In this case, I'm struggling to see what the assumption on which the argument relies actually is; it seems to say that getting rid of lead paint = getting rid of lead poisoning, there is still some lead paint in the area, getting rid of that lead paint gets rid of lead poisoning. The assumption thus looks a lot like the conclusion, unless that's not the assumption.

I went with (c) because that seemed pretty obvious, but (b) perplexed me.

[LSATeater]

Could someone give a more detailed takedown of (b)? I sometimes get thrown by jargon-y answer choices like that one. In this case, I'm struggling to see what the assumption on which the argument relies actually is; it seems to say that getting rid of lead paint = getting rid of lead poisoning, there is still some lead paint in the area, getting rid of that lead paint gets rid of lead poisoning. The assumption thus looks a lot like the conclusion, unless that's not the assumption.

I went with (c) because that seemed pretty obvious, but (b) perplexed me.

Answer choice B, as you described, says that the area resident's argument is flawed because it uses circular reasoning. It doesn't exactly say circular reasoning but defines it instead. On flaw questions, especially ones that appear early in the section (before q10) the answer will almost certainly be in line with your prephrase.

In this argument, the area resident concludes that eliminating lead paint in homes will eliminate childhood lead poisoning. He supports this with the fact that 25 percent of the homes in the area still have lead paint. What's the flaw? Easy, he's presuming that the lead paint in those 25 percent of homes are the only possible sources of childhood lead poisoning. For all we know, the elementary schools and playgrounds also have lead paint and the children are still at risk in those places.

Circular reasoning would be something like:

premise: If we eliminate the lead paint in the 25 percent of area homes that still contain lead paint, then we can eradicate lead poisoning in the area.

conclusion: Therefore, eliminating the lead paint in the 25 percent of area homes that still contain lead paint will eradicate lead poisoning in the area.

[JChapmanIV]

I am struggling to see why B is wrong, certainly there is a flaw in failing to consider other sources, but B, which states the conclusion relies on an assumption that is the equivalent of assuming the truth of the conclusion (I recognized this as circular reasoning). It seems like the argument is in fact reliant on some form of assumption that eliminating the paint eliminates the problem. Which is tantamount to assuming the conclusion is true.
I get how C works as an answer, but how is B wrong?

[timsportschuetz]

(E) is pretty damn tricky! I initially chose this answer since my pre-phrase to this question was ALMOST EXACTLY the same as this answer choice. However, after closely re-reading it, I noticed that this answer choice commits a play on words that is hard to spot! For the argument to work, I immediately thought that the following MUST be assumed: All of the children in the area MUST be living in a house with lead paint. The answer choice is NOT saying the previous. This answer actually states that the children in the area live in EACH AND EVERY house containing lead paint! As a previous poster already explained, this does not have to be assumed. However, I thought that I would try to make it a bit more clear with this explanation.

This answer choice would be correct if it said the following: "Takes for granted that all the children live in homes in the area that contain lead paint."

[bharbin1544]

It took me a total of three times looking at this question to realize my error. During the timed run and blind review, I chose (E). On the third time through reviewing, I realized that the subtle word "all" makes the AC entirely too strong.

[Yit HanS103]

I chose E and then I chose B. I'm clearly lost here and I thought of this as somewhat an easy question, I was wrong.
I eliminated C because the argument premise states " 25% of this area's HOMES still contain lead paint" and the conclusion " eliminate the lead paint IN THOSE HOMES, childhood lead poisoning in the area will be eradicated"

My thinking was: 1. we are only talking about the safety of children
2. the paint lead that poses hazard was only IN THESE AREA'S HOMES (thats a fact, because its in the premise)

Choice C introduces a new information "OTHER significant sources of lead IN THE AREA'S ENVIRONMENT"
why would I care whats in OTHER area's ?

can anyone tell me what is wrong with this?

thank you
pt62 section 2. question #5