#19 - Doctor: Medical researchers recently examined a large

[jessamynlockard]

If slipped discs aren't sufficient to cause back pain, could we think of back pain as a necessary condition (that it can occur in the absent of the sufficient condition)?

[Adam Tyson]

A condition is only necessary if there is something sufficient to ensure that it will happent, jessamynlockard. If we argue that something is not sufficient, then the other condition isn't a necessary condition, it's just a condition. While it is true that a necessary condition can occur even when a sufficient condition does not, the occurrence of a condition does not, by itself, make it necessary. It's only necessary if something else makes it so!

Put all that conditional stuff aside here, though, because this argument is actually causal, not conditional! The author is saying that while some people blame slipped and bulging discs for back pain (in other words, they claim that the disc problems are causing the pain), in at least some cases the alleged cause was present (the disc issues) but the alleged effect was not. Based on that evidence, the author concludes that there cannot be any causal relationship between those two things. The problem with that is failing to consider that the effect may be brought about by multiple causes working together, such that disc problems might be a causal factor even if they are not always causing the pain.

[ieric01]

Hey guys & gals can someone help me understand why A is wrong.

I listed two reasons.

Does the first one make sense?

Would that alone have been a good reason to eliminate (A)?


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A) A factor that need not be present in order for a certain effect to arise may nonetheless be sufficient to produce that effect

If you chose this answer, then you believe the argument is wrong because a bulging disc doesn’t need to be present for someone to experience back pain but it can still be sufficient in itself to cause back pain.

First Reason:

I eliminated this answer because the argument is about bulging disks being present. That’s what the study was about - people with bulging or slipped disks. Now when it’s not present can it still cause back pain? Maybe. But I think that’s outside our scope. Nowhere in the stimulus are there studies about bulging disks not being present and causing back pain found.

Second Reason:

Another reason you could’ve eliminated this choice is if you looked at the keyword “sufficient.” Here it says a bulging or slipped disk is ‘sufficient' to cause back pain. But the author disproves this with their study about ‘half of the members having a slipped disk and not experiencing back pain.’ So, (A) can’t be the answer because we already know a bulging or slipped disk is NOT sufficient to produce back pain (our effect).

[Rachael Wilkenfeld]

Hi ieric01

Great work. The issue here is that the researchers conclude because slipped disks don't always cause pain that they can never be a cause of pain. Answer choice (A) is particularly problematic, because it suggests that slipped disks may be sufficient for back pain. But that's inconsistent with the stimulus showing slipped disks, but no pain. This answer choice means that slipped disks are not necessary for back pain, but may be sufficient for back pain. I think that describes your second reason given. That's the reason that I would eliminate answer choice (A).

Your first reason was interesting. You are right that the stimulus was about what happens when bulging disks were present, and not when they were absent. But with causal reasoning (as we have in this stimulus) the absence of a cause is relevant to the reasoning, so I wouldn't eliminate the answer choice for that reason alone. The second reason you gave is significantly stronger and more tailored to what we actually see with the reasoning here.

Hope that helps!
Rachael

[ieric01]

That definitely helps Rachael, thanks!

One more thing I’m confused on how the “absence of a cause is relevant to the reasoning.” What do you mean?

Look forward to your thoughts!

-Eric

[KelseyWoods]

Hi Eric!

I can clarify what Rachael meant by "the absence of a cause is relevant to the reasoning" for you:

Causal arguments are inherently flawed on the LSAT because it is very difficult to definitively prove a causal relationship. Because causal arguments are so weak, we frequently see them in Weaken and Strengthen questions on this test--so we're frequently being asked to either attack them or help them out. To weaken a causal argument, you essentially want to show that that cause and that effect don't always have to go together. There are several ways to do this but one common way is to show that the effect can happen without the cause (in other words, in the absence of the cause). To strengthen a causal argument, you do the opposite and try to show that that cause and effect always go together; show that when you don't have the cause (or in the absence of the cause), you don't have the effect.

For example, let's say I have a causal argument that states: "Last week, Apple announced a quarterly deficit and the stock market dropped 10 points. Thus, Apple's announcement must have caused the drop."

An answer choice that would weaken that argument could be something like: "Last quarter, Apple announced a quarterly gain (so the cause--a quarterly deficit announcement--was absent) and the stock market also dropped 10 points (the effect was still present)." This would show that you can have the effect without the cause, which would weaken the conclusion that it's Apple's announcement of a quarterly deficit that caused the stock market to drop.

An answer choice that would strengthen that argument could be something like: "Last quarter Apple announced a quarterly gain (cause was absent) and the stock market did not drop 10 points (effect was also absent)." This would show that when you don't have the cause, you don't have the effect, which would strengthen the conclusion that it's Apple's announcement of a quarterly deficit that caused the stock market to drop.

So information about what happens in the absence of a cause is relevant to causal arguments because it can help or hurt them.

Hope this helps!

Best,
Kelsey

[ieric01]

Great explanation Kelsey! Thanks. One last thing, in this case, the author weakens the argument by saying that the cause is present (the slipped disks) but the effect was absent (back pain), so slipped disks can’t be the CAUSE of back pain. That's what they conclude from their study.

But what we’re saying is “No maybe there is a causal relationship between slipped disks and back pain, just not all the time.” This completely changes my outlook on what it means for A to cause B. I always thought if A caused B, then it should cause B all the time. If not, then how is it a a causal relationship? Unless my definition of a causal relationship is wrong.

What’s your thoughts Kelsey?

BTW - The examples were very helpful! Thanks Kelsey.

[Paul Marsh]

Hi Eric! Let's take a closer look at what exactly is flawed about this problem, and what is flawed about Cause and Effect reasoning on the LSAT in general. Take this sophomoric example:

"Professor Jones surveyed the students who showed up to her university class this morning regarding their alcohol consumption. She found that half of those students had consumed at least 6 alcoholic beverages the night before. Yet since they were in class, one can conclude that consuming at least 6 alcoholic beverages does not contribute to missing class."

This argument contains the same flaw as our stimulus: just because something isn't sufficient to single-handedly bring about an outcome, doesn't mean that it can't contribute to that outcome. I think that when you said “No maybe there is a causal relationship between slipped disks and back pain, just not all the time," that's not quite what we're saying with answer choice (B). Instead, it's more like we're saying, "The fact that slipped disks don't single-handedly cause back pain does not necessarily mean that they don't in some way contribute to back pain."

Cause and Effect relationships on the LSAT love to singularly ascribe causation. Like, sticking with the same theme: "Having 6 drinks caused me to miss class". This is a Flaw, since (if you want to get philosophical for a second) every single event that has ever occurred has been caused by multiple things. Maybe the 6 drinks contributed to me missing class. But there are infinite other factors that also contributed to me missing class, like 1) not setting my alarm volume high enough, or 2) me having a sluggish personality, or 3) me going to a school that doesn't really care about attendance, or 4) me being born to parents that don't emphasize work ethic, or 5) the Big Bang, etc etc. Saying that exactly one thing or that some specific combination of things caused an event is, by its very nature, always an oversimplification.

So assigning causation to any one thing, as in "A caused B" - is a flaw. It is not a flaw to say that A may have contributed to B. But it is a flaw to explicitly rule out the possibility that A may have contributed to B. That is what our stimulus is doing in this problem. Cause and Effect relationships can be tricky, and practicing this stuff is key. But remember, whenever a stimulus tries to say that "Oh, this causes this", or "Oh, this definitely doesn't cause this", there is flawed reasoning at work! Hope that helps!

[ieric01]

Thanks Paul, great examples! It definitely clears things up

I tried my own example to prove if I truly understand it. Here it goes:

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For example, eating peanuts might cause allergies for some people but not everyone. If we only looked at cases where people ate peanuts and didn’t get an allergic reaction, using the same reasoning the author used, we would falsely rule out ‘peanuts’ as a possible allergenic. Even though 30% (a made-up number) of the population might still get a severe allergic reaction. Similarly, in this argument, we can’t say A isn’t the cause of B, because we found a group of people with slipped disks who didn’t have back pain. There’s a possibility it could still cause pain in some way.

[Adam Tyson]

Your analysis is good, but it doesn't get to the heart of what is happening in this stimulus or what Paul is saying. The issue here is that even for those people who ate peanuts (to use your example) and had a reaction, eating peanuts may not have been the ONLY cause of the reaction. Perhaps it was a combination of eating peanuts and not taking a prescribed medication that prevents allergic reactions from occurring? Maybe the people who didn't have a reaction did take their meds? This argument is about something possibly being a cause but only in combination with other factors - a partial cause, a contributing factor, or component.