#17 - Traditional hatcheries raise fish in featureless

[Administrator]

Please post your questions below!

[BostonLawGuy]

I am confused with this question which, as a necessary assumption question must pass the "negation test."

I understand that the fish in a more visually stimulating environment are bolder in finding food than those in traditional hatcheries and it is this reason that they are more likely to survive.

But that does not require that some traditional fish are too timid for food finding and therefore die. They could simply be LESS BOLD but not "too timid."

I thought that this may be a correct answer choice for a most strongly supported, but I didn't think it is necessarily true for this argument to be valid.

Thoughts?

[Brook Miscoski]

Boston,

Reading through the stimulus, my reaction was that being bold might get you eaten (prematurely). That would have been a more fun answer. Alas, it was not to be.

Here is the short answer, followed by a longer answer in case I misinterpreted you.

If you got the correct negation of (C) as "No fish die from being too timid in foraging for food" but still believed this did not defeat the argument, please take a look at the conclusion. If food is not a factor in survival, the argument that being more adventurous in trying new food is helpful to survival has been disproved.

If that isn't enough, see the following:


(C) was still the stand-out selectable choice.

(A) About fish surviving, not economics...off topic.
(B) About what is best preparation for any environment, so the argument doesn't assume that environment is irrelevant. Contrary to stimulus, and wrong.
(C) survives--discussion to follow
(D) survives (barely)--discussion to follow
(E) Stimulus is about likelihood, not about what "always" happens. Among other reasons, eliminate this.

The reason I say that (D) barely survives is that the stimulus is just about willingness to try new food, not about having a varied diet. So I eliminated it, personally, right away. Because it could survive, I kept it for the negation test.

Negations follow:

(C) No fish die from being too timid in foraging for food.
(D) Fish don't need multiple types of food to survive.

In negation, (C) would destroy the argument because it indicates that a lack of boldness is unimportant to survival. (D) doesn't hurt the argument, which makes claims about finding food, not about having access to many different types of food.

Reading over your question, I think that what happened is that your negation was off. The logical negation of "some" is "none." If you tried to negate a different part of (C), the problem is that with "some" qualifying the whole of (C), you aren't achieving logical negation. So the target, and the only target, for the negation technique is to change the "some" to "none."

[Leela]

Would this be a supporter assumption question because C connects "bolder" in the premises with "more likely to survive" in the conclusion?

[Isaiah4110]

Isn’t B a blocking type of answer? The new environment in which the hatchery raised fish are released into cannot effect the fish’s survival rate. Doesn’t this have to be true in order to conclude that the increased likelihood in survival rate is attributable to the environment of the experimental hatchery, not something else? In other words, the experimental hatchery raised fish are more likely to survive because they were raised in experimental hatcheries, not because of the effect of the environment they are released into.

[James Finch]

Hi Leela and Isaiah,

Leela -- Absolutely, this is a clear Supporter Assumption question, where we need to tie the trying of new foods (premise) to survival rate (conclusion).

Isaiah -- I believe you're referring to the other major assumption type, the Defender assumption, where a seemingly sound argument requires "defending" from possible outside lines of attack. This question, due to the clear logical gap between the premise and conclusion in the stimulus, is definitely a Supporter Assumption type.

(B) fails as a necessary assumption as either Supporter or Defender because it ultimately doesn't matter where the fish are released, only that fish that are bolder and try more food types are more likely to survive. The fish could be released in areas where survival rates are low for fish from both new and old hatchery types, but the fish from the newer hatchery could still have a better survival rate because they try more food types. If we use the Assumption Negation technique on (B), we can see where it breaks down:

Quality of Environment Has A Big Effect Fish from Experimental Hatcheries Aren't More Likely to Survive

For (B) to work would require another assumption, that either all fish will die or all will live, or that the fish from traditional hatcheries and those from the experimental ones were released in very different environments. So by itself, it isn't actually necessary to the argument.

Hope this clears things up!

[J1445]

I was stuck between AC B & C and I chose B. I felt like AC C was not necessary because if we negate and none of the traditional hatchery fish die from being too timid in foraging for food, then the conclusion could still hold because the fish from experimental hatcheries could still have a survival advantage from being bolder in exploring new environments.

AC B when negated says “the quality of the environment where the fish are released has a major effect on survival rate”. This presents us with a situation where the environment is the factor that increases the survival rate, not the hatchery where the fish were raised. I thought this broke the argument. Does it not break the argument because even if the environment has a major role in the survival rate of the fish, the boldness in exploration and trying food could still increase the fish's chance of survival? (Essentially saying that they are not mutually exclusive).

Lastly, I eliminated AC D because I thought that trying new types of food could help the fish survive without it being necessary for their survival. Is that line of reasoning correct? Thank you!

[Rachael Wilkenfeld]

Hi J,

Good work with answer choice (D).

With answer choice (B), you didn't get the correct negation. We can't jump from "little effect" to "major effect." We need the logical opposite of "little effect" which would include everything from "no effect" to "massive effect." The big problem with answer choice (B) however is that we don't really care much about the environment in which the fish are released. The point of the passage is that the environments in which the fish are released will vary, and we can determine survival likelihood based on the environment in which they are raised, not where they are released. Let's say that the environment in which they are released impacts the survival rate of the fish. Does that mean that they way in which they were raised does not? Does that hurt the argument that experimental fishery fish are more likely to survive? No.

Pretend this was about astronauts. "Astronauts who train in dynamic, challenging environments are more likely to survive on a Martian colony than those who learn everything from books." It wouldn't matter if some parts of Mars were friendlier to colonists than others. The astronauts who trained in challenging environments would be expected to do better than the book peers in any potential environment because they are more flexible.

For answer choice (C), our negation would be that NO fish from traditional fisheries has died from being too timid to find food. That would hurt our argument that the timidity of the fish impacts survivability. If the timidity isn't fatal, we don't know if they are more or less likely to survive. Exploring new environments and finding new food are linked together in the argument, so if you rule out finding food as an issue, you've ruled out the potential weakness of the traditional fish.

Hope that helps!

[J1445]

Helps a lot thank you!

[Justavisitorhere]

I legitimately cannot wrap my head around this question. My analysis follows, please let me know where I am going wrong. Thank you!

*Analysis:*
The allegedly correct answer says that, “Some fish raised in traditional hatcheries die **because** they are too timid in their foregoing for food” and the argument works perfectly fine WITHOUT assuming this.

The stimulus says that bolder fish “explore[] new environments and try[] new types of food” and “therefore, are more likely to survive . . . .” This is a causal relationship.

When 2 causes (exploring + trying new food) are given for 1 effect (longer life) it is impossible to say which of the 2 causes is CAUSING the effect. Maybe both are? Maybe only one is? But to say that 1 cause (trying new food) is ABSOLUTELY NECESSARY for the argument is wrong. It is entirely possible that the ONLY reason the bolder fish “are more likely to survive” is because they “explore[] new environments” that, for example, might lead them to find shelter from predators.

To say, as the alleged answer suggests, that at least SOME fish die **because** of their timidity in seeking out new food is completely unsupported by the facts of the stimulus. You can negate this and say ”NO fish raised in traditional hatcheries die **because** they are too timid in their foregoing for food” and the argument works perfectly fine. The relative decreased lifespan could be purely and exclusively **because** of the relative decrease in “exploring new environments” thus removing any need for the alleged necessary assumption.

In essence: the word *because* in the correct answer is wrong, since another explanation (e.g.: exploring predator-free places) can fully account for the increased lifespan of the bolder fish.