Q17 - A positive correlation has

[ManhattanPrepLSAT1]

This argument's conclusion challenges the notion that the soot causes a certain ailment. Why? Well there are other air pollutants that are in the atmosphere as well. This argument attempts to refute a causal relationship by providing potential alternative causes.

Answer choice (C) works to undermine the argument by providing an example where the ailment and the soot are present, but the other pollutants are not. This challenges the notion that the alternative cause suggested by the argument (other pollutants) could actually be the cause, thereby strengthening the possibility that soot is the cause.

Incorrect Answers
(A) strengthens the argument that the soot is not the cause.
(B) is out of scope. This answer is expressed as a conditional "if/then" and since we know the "if" part is not true, this relationship doesn't apply. It would take negating the logic of this answer to undermine the argument, but negated logic is not valid.
(D) is too weak. This leaves open the possibility that soot is one of the causally contributing factors.
(E) strengthens the argument by continuing to bring in other potential contributing factors of the ailment.

#officialexplanation

[priyanka.krishnamurthy]

Hi:

I chose C on this one, but was not a fan of really any of the ACs. Could someone walk me through the elimination process?
Thanks in advance!

[JamesM914]

This argument's conclusion challenges the notion that the soot causes a certain ailment. Why? Well there are other air pollutants that are in the atmosphere as well. This argument attempts to refute a causal relationship by providing potential alternative causes.

Answer choice (C) works to undermine the argument by providing an example where the ailment and the soot are present, but the other pollutants are not. This challenges the notion that the alternative cause suggested by the argument (other pollutants) could actually be the cause, thereby strengthening the possibility that soot is the cause.

Incorrect Answers
(A) strengthens the argument that the soot is not the cause.
(B) is out of scope. This answer is expressed as a conditional "if/then" and since we know the "if" part is not true, this relationship doesn't apply. It would take negating the logic of this answer to undermine the argument, but negated logic is not valid.
(D) is too weak. This leaves open the possibility that soot is one of the causally contributing factors.
(E) strengthens the argument by continuing to bring in other potential contributing factors of the ailment.

#officialexplanation

Hmmm no offense but your explanation of why B is wrong doesn't seem right to me. The "if" part could definitely be true. You can't say for sure that it's not true.

[SoniaK600]

Any Takeaway/Pattern for this kind of weaken Q type?

[snoopy]

Any Takeaway/Pattern for this kind of weaken Q type?

This was a correction = causation flawed argument although worded in a different way. Stimulus says positive correlation found between amount of soot and frequency of an ailment. Conclusion is that even though there is a positive correlation, soot does not cause ailment since there could be other impurities in the air. Implication is that the other air pollution could have caused the ailment.

Pattern with correlation =/= causation arguments is you ALWAYS question "what if X did/didn't cause Y?" Maybe a lot of soot in the air DOES cause the ailment. How would you prove this? By looking at cities with large amounts of soot but little air pollution and seeing the frequency of the ailment. C is this answer.

You could also weaken the conclusion by comparing two cities that 1) have little soot in air vs. a lot of soot in the air with equivalent amount of air pollution OR 2) compare little air pollution vs. a lot of air pollution with equivalent amount of soot. Then, you'd look at the frequency of the ailment.

[zijiez700]

Great discussion! The thing that really bothers me about answer "C" is the prase "anywhere else," could the anywhere else include the places where there is a large amount of other pollulants and a small amount of soot? If that's the case, doesn't it somehow weaken the argument? and just being kind of out of scope? Someone please help me to think this through!

[NoahH732]

This argument's conclusion challenges the notion that the soot causes a certain ailment. Why? Well there are other air pollutants that are in the atmosphere as well. This argument attempts to refute a causal relationship by providing potential alternative causes.

Answer choice (C) works to undermine the argument by providing an example where the ailment and the soot are present, but the other pollutants are not. This challenges the notion that the alternative cause suggested by the argument (other pollutants) could actually be the cause, thereby strengthening the possibility that soot is the cause.

Incorrect Answers
(A) strengthens the argument that the soot is not the cause.
(B) is out of scope. This answer is expressed as a conditional "if/then" and since we know the "if" part is not true, this relationship doesn't apply. It would take negating the logic of this answer to undermine the argument, but negated logic is not valid.
(D) is too weak. This leaves open the possibility that soot is one of the causally contributing factors.
(E) strengthens the argument by continuing to bring in other potential contributing factors of the ailment.

#officialexplanation

Hmmm no offense but your explanation of why B is wrong doesn't seem right to me. The "if" part could definitely be true. You can't say for sure that it's not true.

Hopefully my below thoughts might help explain why Answer B would need to be false. I am not an LSAT Expert though....

Answer B states, "If the ailment rarely occurs except in cities in which there are large amounts of soot in the air,..."

A premise in the Passage states, "A positive correlation has been found between the amount of soot in the atmosphere of cities and the frequency of a certain ailment among those cities' populations."

What difference do you see here? Answer B's "if" part is going against the premise.
The passage's premise gave us no specification as to how much soot needs to exist in an atmosphere for the correlation to be true (could be large amounts or small amounts).
Answer B is feeding us a contaminated reading of passage. It tries to trick us to interpret the SUFFICIENT scenario the author discusses (yes, Large amounts of soot would correlate with large amounts of the ailment) as a NECESSARY scenario.

Answer B's "if" statement cannot be reasonable true if the premise is also still to be true.

An argument you could make, to have both Answer B and the premise's conditions be true, is that soot too rarely occurs except in cities where there are large amounts of the ailment. aaand that counteracts the other half of that answers: that soot is probably the cause of that ailment--because the truth condition (that soot is rare unless there are large amounts of the ailment) leads us to think otherwise.

[ohthatpatrick]

Let me try to clean up a few lingering issues on this one.

This is an anti-causal argument, since the conclusion is saying "soot is NOT causing ailment X".

But we can still think through this argument as we do almost all causal arguments:
CURIOUS FACT / EXPLANATION

The CURIOUS FACT:
why is there a correlation between atmospheric soot and ailment X?

Some people's EXPLANATION:
the soot causes ailment X.

Our author's ALTERNATE EXPLANATION:
no, it's the other pollutants in the air causing ailment X
(they are also correlated with atmospheric soot).


We can weaken this argument by making the author's explanation seem less plausible or by making the original "soot is the culprit" explanation seem more plausible.

(B) is set up, formally, to make it seem like the original "blame soot" explanation is probable. However, in order for it to have any effect, we need to trigger that conditional. Do we know if ailment X rarely occurs except in cities with lots of atmospheric soot?

No, we only know that the frequency of ailment X is higher in the cities with lots of atmospheric soot.

As an analogy, the US might have a higher frequency of diabetes than France does, but that doesn't mean we can say that "diabetes rarely occurs in France".

The concern with (C) is that it also ropes in other cities, with low concentrations of atmospheric soot.
The person posting was thinking, "If these soot-only cities have the same concentration of ailment X as cities that don't even have atmospheric soot, wouldn't that make it sound like atmospheric soot couldn't possibly be the causal difference maker for ailment X?"

Yes, that would be true. However, (C) doesn't say the soot-only cities have the SAME frequency of ailment X; it says these cities have AT LEAST THE SAME frequency.

(C) is potentially describing this type of breakdown:

cities with only soot: 57% frequency of ailment X
cities with soot and other air pollutants: 57% frequency of ailment X
cities without soot (whether or not they have other pollutants): 40% frequency of ailment X

The meaningful part of (C) is the relationship between the first two categories. Our AUTHOR thinks that "other air pollutants" are the causal difference-maker that accounts for ailment X.

This data shows he's wrong. If you compare soot-cities, and the ones WITH the other air pollutants aren't any higher for ailment X than the ones WITHOUT the other air pollutants, then you can see that these other air pollutants don't make a difference in terms of the frequency of ailment X.

That undermines our author's alternate explanation for the higher prevalence of ailment X.