PT28.S1.Q05 - the number of codfish

TheDeterminedC

https://7sage.com/lsat_explanations/lsat-28-section-1-question-05/
Here is the LSAT question from the problem set I am currently on in the course.

I have really got down the strengthening questions and I actually think they are quite fun. But the weakening questions are ironically my weakness at the moment.

The question:
I chose C in the initial timed test and stuck with it after the blind review. I totally see now how C completely supports the hypothesis, and is therefore wrong. But I was really analyzing D.

In the blind review, I wrote down that the reason I did not chose D was because it makes an assumption that Caplin fish are in a low supply. They both eat the same fish, so what? What if there are millions of these fish in great supply, than this would not matter at all. It also makes an assumption that Harp seals are better at catching and eating Caplin than Cods are. This assumption is still too large for me to understand why it would be the right answer choice.

I guess, by default, it would be right answer choice, since all the others are very wrong. But I would really appreciate someone explaining when I should have a critical eye for assumptions and when I shouldn’t, because it has obviously has swayed me in the wrong direction.

BinghamtonDave

Sometimes, the counting of/accounting of assumptions can get us turned around on questions. Believe me, it has happened to me tons of times across my prep. Moving forward, what has helped me immensely is 1.stay focused on the task (here the task is to weaken) and 2.stay focused on what is being said/who is saying what. A close focus on 2 often reveals gaps in the logic that we can exploit.

On this problem we have our author trying to disprove other people's opinion/other people's hypothesis. So lets start with what is the other people's hypothesis? That because of the increase in the harp seals while there is a decrease in the cod fish, that from that correlation, there is some sort of causal element at play. That casual element according to other people is that the increase in seals caused the decrease in cod fish. Lets pause there: commit what other people just did there to memory. They drew a causal conclusion based off of correlative evidence. You will see that same thing scores of time without your prep. Pausing here, I would ask you how generally you would weaken and how you would strengthen other people's opinion. I would also ask you to describe it in abstract flaw question language. There are a ton of miles we can get out of just the other people's hypothesis. But lets move on:

"But" is an important word. It signifies the switch from contextual information to a possible argument. So how does our author try to deal with other people's argument? Our author says: because harp seals have diets that contain "negligible" amount of cod, the increase in the seals didn't decrease the cods.

That isn't great support. We are tasked with weakening that support/conclusion relationship. Which is a support/conclusion relationship used as a way of disagreeing with other people's opinion. Pre-phrasing for me, I was looking for something that said that the cod population was already endangered and that even a 50% increase of something that ate negligible amounts of it was damaging. Imagine there was only 100 cod fish on earth. And something that ate 1 codfish every 30 days increased by more than 50%=the cod fish are in trouble.

But the answer choices didn't go there. Instead they went for something else: remember, we are trying to weaken the idea that because the harp seals eat negligible cod fish therefore they didn't contribute that much to declining numbers. What if this 50% increase in seals ate the cod fish's meals?! That would weaken the idea that simple because the harp seal barely eats cod fish then there was no causal relationship between increased harp seals and decreased cod fish. It weakens the concept that harp seals eating cod fish would be the main way of harp seals decreasing cod fish.

Here we get to the very core of the psychology in which the LSAT presents to us. Check this out: we have a propertied relationship: harp seals up, cod fish down. Other people conclude that there must be a cause there of the harp seals up causing the cod fish down. Ask anyone and I bet 99 times out of 100, people will think the harp seals eat the cod fish. Our author plays to that prevailing paradigm: saying essentially: the harp seal doesn't even like the cod fish's taste, they couldn't have caused it. That is a deeply deeply rooted assumption operating within this argument. Instead, as lawyers, we must think beyond those assumptions. Stuff like: maybe the harp seals drove the cod fish out of their reef habitats? Maybe the seals have a bacteria that hurts only the cod fish? or maybe, the seals eat the thing that the cod fish subsist on!

This is a common pattern with the LSAT. Maybe even a theme.

Now, what does (C) give us? (C) gives us something that weakens the other people's opinion and strengthens the author's opinion. (C) tells us that the seals and cod are separated by water temps. How does the application of (C) weaken the idea that the seals didn't cause the decrease in cod because they only eat a few?

I hope this helps
David

TheDeterminedC

@BinghamtonDave Thank you so much for your detailed response, it helps a ton. I will keep those two steps in mind, they sound great. I feel as if this will ground my brain from trying to rip apart every answer choice I see.

I appreciate it, Dave!

Sami

@"Corey L" said:

In the blind review, I wrote down that the reason I did not chose D was because it makes an assumption that Caplin fish are in a low supply. They both eat the same fish, so what? What if there are millions of these fish in great supply, than this would not matter at all. It also makes an assumption that Harp seals are better at catching and eating Caplin than Cods are. This assumption is still too large for me to understand why it would be the right answer choice.

Hey : )

So the way a weakening argument works is that if you can even weaken the argument just by a bit, its still weakening. So if an answer choice weakens an argument by anything from 1%-100% , it will be correct.

The reason answer choice "D" works despite the fact that it is possible for both to eat Capelin and there be enough capelin to have both population survive is because of the argument form of this stimulus.
In our stimulus:
Premise: cod plays a negligible role in seals diet
Conclusion: increase in seal population not responsible for decline in cod's population.
*Analysis: the author here is only considering one aspect, the diet, in considering how the increase in seal population could be a factor in decline in cod's population and we want to weaken the argument by saying there is more things to consider than just that.

Answer choice "D" does just that.
It agrees with the premise, that seals don't eat cod that much but it also says you have not considered everything. You have not considered there is another factor that could affect this relationship and could cause an increase in seal population to be responsible for a decrease in cod's population. The fact that they feed on capelin.

Answer choice "C" is talking about how seal thrive in this cold water. But this doesn't go against our conclusion, that the increase in seal population is not responsible for decrease in cod population. We want to link these two things closer in a relationship where the increase in seal population would effect cod's population. But answer choice "C" doesn't do that. It's linking the coldness of water as responsible, we need the seal's population increase to be responsible for cod's population increase.

That's why D is so much of a better answer. It's telling you there is another way that an increase in seal's population could cause a decrease in cod's population, through this capelin. It doesn't have to be true, but its something that the author hasn't considered that might link these two more causally together.

I hope this helped.

BinghamtonDave

And as an aside @"Corey L" those assumptions are great to keep an eye on, but we don't have to make them to satisfy our task here. (D) tells us that there are other ways in which the seals could have decreased the cod population aside from eating them. Leaving this possibility open does enough for us to weaken the argument. Lets consider an analogous argument in the form of a conversation:

You: I think you should buy a really nice road bicycle.
Me: No, I would much rather do cardio on the treadmill at the YMCA, I can get the same exercise.

Weaken answer choice: having a road bike enables people to see great biking trails while enjoying nature that they otherwise would have neglected.

An assumption here would be that people would actually want to see those trails, that they would actually like those trails, they they aren't allergic to a very specific form of pollen contained on those trails that makes life immensely more difficult for them than would otherwise would be the case. All of these are valid assumptions, but simply leaving the door open on the idea that there is more to having a road bike than the exercise you can get is enough for you to weaken my argument.

I hope the above analogy helps. Try to dispense it on the next weaken question you come across. Any further questions, don't hesitate to reach out.

David

TheDeterminedC

@Sami This totally helped. > 1%-100% , it will be correct.
This really puts the answers in perspective. I will work on being more attentive to the suggestions of a third party factor, regardless if I think it is a plausible explanation or not.

You helped me see that I am overlooking the answer, that I am not congenitally thinking about what a right explanation would be before hand. Without this, it makes the process of finding the right choice very difficult.

Thank you!!

Sami

@"Corey L" said:
@Sami This totally helped. > 1%-100% , it will be correct.
This really puts the answers in perspective. I will work on being more attentive to the suggestions of a third party factor, regardless if I think it is a plausible explanation or not.

You helped me see that I am overlooking the answer, that I am not congenitally thinking about what a right explanation would be before hand. Without this, it makes the process of finding the right choice very difficult.

Thank you!!

That makes me happy to know it helped : )

Yeah at one point I had to drill to force myself to think of a pre-phrase of what the right answer choice might look like before I went to the answer choices. It took me a while to form this habit but its really really helpful and gives you speed as well as helps you avoid trap answer choices.