Logical Reasoning

PT115 · S2 · Q21 Cognitive psychologist: The majority of skilled

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Cognitive psychologist: The majority of skilled artists are very creative people, and all people who are very creative are also good at abstract reasoning.

Conclusion

Some people who are good at abstract reasoning are famous.

Evidence

Most skilled artists are very creative people, and all people who are very create are also good at abstract reasoning.

Evaluate

Whenever we do Sufficient Assumption, we can ask ourselves, "Is there any New Term in the Conclusion?" If there is, then that term/idea has to appear in the correct answer, or else we'll have no way to derive that conclusion.

In this case, the evidence does talk about people being good abstract reasoning, but it never talks about anyone who is famous.

Confusingly, it does talk about people who are not famous.

Not all skilled artists are famous = some skilled artists are not famous.

Whenever we see any negative formulations, we want to perform a Negative to Positive translation: No A's are B = All A's are ~B Few A's are B = Most A's are ~B Not all A's are B = Some A's are ~B

When we say that "Not all A's are B", it does not imply that Some A's are B.

For example, it's false to say "All NFL players are female", thus it's true to say "Not all NFL players are female".

All that statement means is .

So since the evidence only told us "some skilled artists are not-famous", we don't yet have any information about any famous people.

Thus, the correct answer has to be a fact about famous people, in order for it to allow us to derive a conclusion about famous people.

What do we know about "good at abstract reasoning" (the other half of the conclusion)? We know that if you're very creative, you're good at abstract reasoning.

Goal

So one possible answer could say, "Some famous people are very creative", and that would then allow us to prove that "Some famous people are good at abstract reasoning".

But we'll consider any answer that talks about famous people and allows to prove that at least one of them is good at abstract reasoning.

21.

The cognitive psychologist's conclusion follows logically if which one of the following is assumed?

  1. Most skilled artists are good

    Unrelated to Goal

    This answer doesn't mention "famous" people, so it's useless to us. Since the argument never mentions any famous people, this correct answer needs to. Furthermore, this answer is just providing a derivable inference, i.e. it's just telling us something we already know. Most skilled artists are Very Creative + Very Creative → Good at abstract reasoning ----------------------------------------------------------- Most skilled artists are Good at abstract reasoning We would never pick an answer on Sufficient Assumption that tells us something we already know. We're looking for a new, additional fact or rule that can add on to the existing evidence and allow us to derive the conclusion. There's no way this recipe of claims: Most skilled artists are good at abstract reasoning Most skilled artists are

    25% picked this

  2. Most people who are very

    Unrelated to Goal

    This answer doesn't mention "famous" people, so it's useless to us. Since the argument never mentions any famous people, this correct answer needs to. This answer + the evidence would give us these claims to work with: Most very-creative are skilled artists Most skilled artists are very-creative All very-creative are good at abstract reasoning Some skilled artists are not famous There's no way from those claims we could derive that "some people good at abstract reasoning are famous", because that set of facts has not mentioned anything about famous people. (Reminder: being told that Some A's are ~B does not allow us to think that Some A's are B, and vice versa)

    6% picked this

  3. Some skilled artists are not

    Unrelated to Goal

    This answer doesn't mention "famous" people, so it's useless to us. Since the argument never mentions any famous people, this correct answer needs to. Furthermore, this answer just repeats something we were already told. The claim "not all skilled artists are famous" means nothing more and nothing less than "some skilled artists are not famous". We would never pick an answer on Sufficient Assumption that tells us something we already know. We're looking for a new, additional fact or rule that can add on to the existing evidence and allow us to derive the conclusion.

    13% picked this

  4. All people who are good

    Unrelated to Goal

    This answer doesn't mention "famous" people, so it's useless to us. Since the argument never mentions any famous people, this correct answer needs to. This answer + the evidence would give us these claims to work with: All good at abstract reasoning are very-creative All very-creative are good at abstract reasoning Most skilled artists are very-creative Some skilled artists are not famous There's no way from those claims we could derive that "some people good at abstract reasoning are famous", because that set of facts has not mentioned anything about famous people.

    6% picked this

  5. Correct

    Most skilled artists are famous.

    Why this is right

    Well, even if we were confused about how this one works, it's the only eligible answer choice because it's the only answer choice that provided any fact about "famous people". How does it allow us to prove that some people good at abstract reasoning are famous? Well, the two premises combine to give us this: Most skilled artists are Very Creative + Very Creative → Good at Abstract Reasoning ------------------------------------------------------------ Most SA's are Good at Abstract Reasoning If we know that most skilled artists are good at Abstract Reasoning and most skilled artists are famous then we can derive that "Good at Abstract Reasoning" and "Famous" have to overlap. There has to be at least one thing who is both. This is the famous Most + Most quantity overlap inference we learn: Most A's are B + Most A's are C -------------------------- Some B's are C (Some C's are B) This is a formula we should have memorized. Here's why it works. Suppose we say, Most of my friends are right handed. Most of my friends are basketball fans. Does there have to be a right-handed basketball fan in the group? Yes. Let's assign numbers to show why. Suppose I have 9 friends. The minimum to qualify as "most" would be 5. So if most of them are right handed, that's 5 righties, 4 lefties If most of them like basketball, that's 5 basketball fans, and 4 non-basketball fans Is it possible for right-handed and basketball-fan to never overlap? Nope. I could make 4 of the 5 basketball fans left-handed (because there are 4 lefties), but the other one is going to overflow into the right-handed column.

    Skill tested: Sufficient Assumption · how this choice captures the argument's function is the move to repeat next time.

    50% picked this

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