PT49.S2.Q11- "Cholesterol, which is a known factor..."

Sarah889

Hey All,

So I have an issue regarding this question and would love some input.

P1: Cholesterol is a known factor in coronary heart disease and stroke.
P2: Cholesterol needs a carrier, known as lipoprotein to transport it through the bloodstream.
P3: Low-density lipoproteins (LDLs) increase the risk of coronary heart disease and stroke.
P4: Aerobics exercise increases ones high-density lipoproteins (HDL).
P5: HDL levels are higher in women than in men.
P6: Both aerobic exercise and being female are positively correlated with lower risk of coronary heart disease and stroke.
C: Therefore, we can tentatively conclude that HDLs help prevent coronary heart disease and stroke.

Humor me for a moment. If I told you that "Food is a known factor in obesity", what can we logically infer from that? That food plays some sort of role in obesity. We cannot say that the lack of food, surplus of food, or type of food is the problem because we don't know more than the fact that food is a relevant component to this condition. We would need to bring in our outside knowledge of obesity to know that it's typically the surplus of food that is the contributing factor. This reasoning is what is going on in my head during this question, and is why A was so attractive to me.

A- I chose A because the argument never said that the presence of cholesterol is a contributing factor in coronary heart disease and stroke. P1 says that it is a factor, but without allowing outside knowledge into our reasoning, based on just the information we are given, we can only really conclude that cholesterol plays some sort of role. Maybe that role is that high cholesterol contributes to coronary heart disease and stroke, or maybe its that low cholesterol does? Or maybe only certain types do? I figured this question was playing on our outside knowledge of cholesterol, because the argument that we are given never says that high cholesterol is what is bad. It just says cholesterol in general is some sort of factor. P1 would need to say something like "Cholesterol is a known contributor in coronary heart disease and stroke." Or even "High cholesterol is a known factor..." would be better.

(Outside info- HDLs are considered good cholesterol. So why would excreting good cholesterol from the body necessarily be a good thing? I'm sure there is a scientifically sound answer to this but, in terms of the LSAT, what's relevant is the major assumption here.)

B- I didn't have a problem eliminating B

C- I see why this is the correct answer...I just couldn't quite come to terms with A.

D- I didn't have a problem eliminating D.

E- I didn't have a problem eliminating E.

Thanks in advance.

LSATcantwin

We are told that cholesterol is a known factor in coronary heart disease and stroke.

We also know that it needs something to carry it through the blood stream.

We are told that LDL increases the risk of heart disease and stroke.

Then we are told that HDL's might actually prevent it.

What this tells us is cholesterol plays a factor in heart disease and stroke. We don't need to know what role.

If I said;

Yeast is a factor in baking bread. We don't need to know what yeast does, we just know it contributes in some way. We can also say that if we take yeast away, making bread will be more difficult because we took a factor involved in making bread away.

This is what AC A does. It shows HDL's taking a factor (cholesterol) of heart disease and stroke away. This means that there are now less factors contributing to heart disease and stroke. We still don't know HOW it worked, or WHY it worked. We just know that something that can factor in is now being reduced.

I'm not sure if this makes any sense lol. I tired....

Sarah889

@LSATcantwin That does make sense...I guess my issue is that, what if cholesterol is a beneficial factor? As in it's a factor that decreases the chance of heart disease and stroke? Based on the limited information we are given, that could be the case. What I don't love is that we are not rid of this option. If this were the case, cholesterol leaving the body would actually increase the chance of heard disease and stroke.

LSATcantwin

@bswise2 said:
@LSATcantwin That does make sense...I guess my issue is that, what if cholesterol is a beneficial factor? As in it's a factor that decreases the chance of heart disease and stroke? Based on the limited information we are given, that could be the case. What I don't love is that we are not rid of this option. If this were the case, cholesterol leaving the body would actually increase the chance of heard disease and stroke.

I do see that, I think they just want us to sort of make a leap to say that it is a factor in contributing to it and not helping. I do see why it's a leap but in the LSAT world it seems to be one they'd consider "small"

Sarah889

@LSATcantwin Haha I hate LSAT leaps...but I see what you're saying and I think you're right.

BinghamtonDave

The LSAT does allow us to take into consideration outside knowledge. I think the idea that we should labor to not include any outside information into our assessment of answer choices at a certain point can be counterproductive. Check out: 76-2-10 about elephants. Pivotal to this question is our outside knowledge that elephants have 4 feet. That information is not provided to us and a sufficient assumption could have been structured to avoid us reaching into our common knowledge, but they didn't go that route. Instead they counted us knowing that 2 or 3 feet are not all the elephants feet, because 2 or 3 are not 4.

Remember, the instructions on every LR section in LSAT history tell us not to make assumptions that are "...by common sense standards implausible, superfluous or incompatible with the passage." The exam writers are careful about every word they use, they didn't say: don't make assumptions or never bring in any outside information from the world you've experienced your whole life. I do realize as a fellow test-taker that I don't quite know where precisely to draw the line of what is alright and was is not alright, but the idea that elephants have 4 legs/feet and lowering cholesterol contributes to lowering the risk of stroke and heart disease seem to me to be acceptable.

Finally, let's take a look at the first sentence of that problem:"Cholesterol, which is a known factor in coronary heart disease and stroke..." You say in your question of this sentence: "Maybe that role [known factor] is that high cholesterol contributes to coronary heart disease and stroke, or maybe its that low cholesterol does? Or maybe only certain types do?"

I do not think the latter two things can at all reasonably be said to be implied here. I think a colloquial understanding of that sentence reads: "The substance cholesterol is a factor in coronary heart disease and stroke." Where unwarranted assumptions might get us into a bit a trouble would be to say:
-cholesterol is the main factor
-cholesterol is the only factor

I hope this helps
David

Sarah889

@BinghamtonDave Thank you! I actually have not yet taken PT76, but this is a good lesson for me to learn. It's my personal opinion that high cholesterol contributing to heart disease is less of a common sense assumption than elephants have 4 legs, but it's good to know the range of what the LSAT writers call a "common sense assumption."

OlamHafuch

I think that the language, "a known factor in heart disease and stroke" means that it contributes toward it. I think if it prevented heart disease and stroke, it would have said, "a known factor in preventing heart disease and stroke." I don't think that cholesterol's effect on the heart is a common sense assumption they expect you to make.