Logical Reasoning

PT152 · S2 · Q23 A scientific study provides

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A scientific study provides evidence that crows are capable of recognizing threatening people and can even pass their concerns on to other crows.

Conclusion

Crows are capable of recognizing threatening people and can even pass their concerns on to other crows.

Evidence

A few years ago, some researchers wearing rubber caveman masks trapped wild crows and then released them in the same area.

Years later, people wearing the same masks near where the crows had been trapped were shrieked at and dive-bombed by crows.

Evaluate

Wow, a lot to unpack there, including these potentially unethical researchers who donned rubber caveman masks before torturing some crows? We'll leave that for a sec.

The conclusion makes two claims about crows: - they're capable of recognizing people - they can pass their concerns onto other crows

What's our evidence that they recognize people? - the author thinks that when people wearing the same masks returned to the "scene of the crime", the shrieking and dive-bombing were evidence that the crows recognized these caveman-looking humans, remembered what they had done years back with the trapping, and responded to them with shrieking and dive-bombing as a result.

But we don't have to accept that shrieking / dive-bombing was a response to their memories. It doesn't have to be that they were like,

There could be some alternate explanation for why the mask-wearers got shrieked and dive-bombed. Maybe they were unknowingly walking near where the crows had hidden some precious food or near where the crows were hiding their nests / their young.

This argument has to assume that .

What evidence has the author provided that crows can pass along their concerns to other crows? - Not really any? I guess maybe the author is assuming that some of the original crows are dead, and they warned their children / grandchildren,

Goal

Let's look for an answer establishing something that would need to be true in order for the old crows to have passed concerns along to new crows, or for an answer ruling out a different explanation for the shrieking / dive-bombing, or for any answer spelling out something the author is clearly thinking in making this argument.

23.

The argument depends on the assumption that

Correct
some of the crows that
Why this is right
The language here ("some") is lovably weak. How do we know that our author was clearly thinking that at least one of the shrieking / diving crows was someone who wasn't around for the first incident? Well, where else would this notion of "crows can pass their concerns on to other crows" come from otherwise? If the author thinks that this study suggests that crows can pass on their concerns, he must be thinking that some of the shrieking / diving crows had been warned by other crows about these people. If we negate this answer, we get a double-negative "none of the crows were not among the crows that had been trapped", which translates into "all of the crows that shrieked / dived were among the crows that had been trapped". If all the crows in this shrieking / diving incident were crows who were originally trapped, then where is the evidence that crows are passing their concerns on to others? Negating this answer badly weakens the second half of the conclusion. If a conclusion makes two claims, you can weaken the argument by impugning claim 1, claim 2, or both.
Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.
66% picked this
crows that perceive an individual
Too Strong: always Reversed Logic
Would it matter if they only responded to threatening people with shrieking and dive-bombing 99% of the time, rather than 100% of the time? Of course not. That's why we know the author doesn't need to assume that in 100% of cases, crows react to threatening people with shrieking and dive-bombing. Given that "always" is conditional strength, we could look at this answer as a conditional and ask ourselves, "Did the author make this move?" perceive someone ? shriek and dive bomb as threatening That's actually the reverse of what the author did. He knows that the crows shrieked and dive-bombed, and from there he assumes that the crows recognized the people wearing masks as threatening. So our author is really assuming that if they shriek / dive-bomb ? it's because they perceive someone as threatening
23% picked this
most birds of any species
Out of Scope
Out of Scope: any species Too Specific: most "Most" is wrong 99.5% of the time we see it on Necessary Assumption, since the difference between saying "most birds are X" vs. "not the case that most birds are X" is the difference between saying "it's at least 51%" and "it's at most 49%". Negating 'most' makes such a slight difference, that the negation almost never weakens, so the answer is almost always wrong. The fact that this answer says "most birds of any species" instantly tells us it's out of scope, since this argument is strictly about crows, so the author doesn't need to be assuming anything about other types of birds.
2% picked this
even in places where crows
Opposite
This also use the word "most", which we explained in (C) is wrong on Necessary Assumption 99.5% of the time we see it. But more egregiously, this answer goes against what the author believes. She doesn't think that crows will shriek and dive-bomb at just any ol' person who's wearing a caveman mask. She is arguing / assuming that the crows shrieked and dive-bombed these caveman mask-wearers specifically because they recognized them as the devious trap & release cavemen from years ago. So our author is assuming that most crows would not usually just shriek and dive-bomb; she thinks this is a "special" (not common) response that was triggered by a memory of the trauma inflicted by the mask-wearers.
3% picked this
crows can distinguish between people
Too Specific
We have no idea what the author thinks, if anything, about this unknown comparison. Our author is saying that crows can recognize threatening people -- she doesn't say "as long as they're wearing a mask ..." If we negated this answer and said, "Hey, author, crows can distinguish between mask wearers and non-mask wearers, as well as recognize individual human faces", would that hurt the argument? No, it kind of sounds like it would even help the author to establish that crows can recognize individual human faces.
6% picked this

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