Q4 - The size of the spleen

[ganbayou]

I chose C and still not sure why D is correct...
in the stimulus it compares the ones killed by predators and died accidentally in the last sentence.
I thought maybe birds with normal size of the spleen was killed by the predators equally as the ones with smaller spleen.
How can D be correct? and why is C wrong?

[ManhattanPrepLSAT1]

Hi ganbayou! I think you may have misread the second statement below.

We know the following:

1. The size of the spleen is a good indicator of the health of a bird: sickly birds have smaller spleens.
2. Birds killed by predators have smaller spleens than birds killed accidentally.

Those two statements together support answer choice (D).

Incorrect Answers
(A) is too strong. It may be more difficult for predators to kill healthy birds than sickly birds, but not unable.
(B) is unsupported. We know that birds killed by predators have smaller spleens, but not the reverse.
(C) is too strong. We cannot say how it is that predators do what they do.
(E) is unsupported. We know that small spleens are associated with sickly birds, but not causation.

[ganbayou]

I cannot believe I missed this question again...
So for some reason I treated this as conditional question.
So I thought
Premise: (stimulus)
A (sickly birds)→(generally )smaller spleens
killed by predators→(generally) smaller spleens

Conclusion: (answer choice) (D)
Sickly birds→(generally)killed by predators

Assumption
killed by predators→(generally) sickly birds

....I was confused.
I should not use conditional signals for "generally" or "likely" sentences?

[andrewgong01]

What does it mean by "birds killed accidentally"? Like are these birds killed accidentally by predators or birds killed accidentally by humans? If it is the former then I would say "C" makes more sense as it shows there is some judgement involved in purposely going after the weaker and sicker birds. However, if it is the latter (human accidents) then i see how it is "D". However, for some reason on this question, considered as an easier one on the Navigator, I am not seeing what accidentally is referring to or signs of what accidently refers to.

[AyakiK696]

I was stuck between C and D too, and ultimately went with C, because I thought that we couldn't just infer an absolute fact (the birds that had been killed by predators were sickly) from a relative fact (the birds killed by predators had substantially smaller spleens than birds killed accidentally). I see how my reasoning was wrong now, though; in choosing C, I was implicitly inferring D. You can't choose C without also assuming D, since for C we have to make an extra leap to make a statement about WHY predators chose those birds. It could just be that the birds were slower and easier to catch. Also, I can see now how we can take the relative fact from the stimulus to infer an absolute fact, since we know that "sickly birds generally have SIGNIFICANTLY smaller spleens than healthy birds" and "birds killed by predators (as an entire group) had SUBSTANTIALLY smaller spleens than birds killed accidentally." So my final takeaway from this Q was: If two answer choices seem to overlap, it's generally safer to choose the broader answer choice. Is this correct?

[ohthatpatrick]

You're close to a true rule of thumb for Inference, but I wouldn't use the term "broader" because it will vary.

You're just thinking,
If (C) is true, then (D) is also true
whereas
(D) can be true without (C) being true

Since (C) implies (D), you want (D).

There can't be two correct answers.

If one answer implies a second one, you want the second one.

And in general, (D) is safer because it is just a numerical description of reality. (C) speculates a causal mechanism that underlies the numerical description of reality.