Logical reasoning PrepTest 155 · Section 1 · Question 9

The concept of "others" isn't found in either the premises or the conclusion. The correct answer on a Strengthen with a Sufficient Premise question must connect the premises to the conclusion in a way that fully validates the conclusion. So an answer choice that introduces a new concept is always incorrect.

Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen w/ Sufficient Premise

Stimulus Summary:
Practical intelligence is about figuring out how to get what you want. This is a skill, which is defined as, "something that doesn't develop on its own." So someone who always got whatever they wanted could never gain practical intelligence.

Strategy Overview:

1. Argument or facts? Always argument, so identify premises and conclusions of argument
2. Anticipate why the premises are not enough to show that the conclusion is true
3. Use anticipations to select the answer choice that:
   1. Guarantees the truth of the conclusion

Answer Anticipation:
On Strengthen with a Sufficient Premise questions, we need to find the answer choice that makes the conclusion valid if added as another premise. Before we can figure that out, we'll need to identify the premises and conclusion. Fortunately, they're not trying to hide this conclusion. The word "Thus" indicates that the last sentence is a conclusion. The preceding two sentences are premises.

After completing many of these questions, observant LSATers start to see a pattern. For most Strengthen with a Sufficient Premise questions, the author will introduce a "new," important idea in the argument's conclusion. The premises will not touch on this "new" important idea. In introducing this new idea, the author creates a gap between the premises and conclusion. The correct answer will address the gap between the premises and the new idea, often simply linking the two concepts with a strong conditional statement.

In this conclusion, "getting whatever you want instantly" is the new idea. To make this argument valid, we need a premise that directly references getting what you want without working for it (or the negation of that — not having what you want unless you get it yourself).

The correct answer will probably connect the new idea to the premise about "skill" of figuring out how to get what you want. We know that this skill doesn't evolve on its own. But does "getting whatever you want instantly" mean you won't try to develop the skill of figuring out how to get what you want? Maybe not The correct answer will likely link these ideas together: "If you get whatever you want instantly, then you won't bother trying to develop the skill of figuring out how to get what you want."

Answer Choice Explanation:
This may not be precisely what we anticipated, but it nonetheless connects the premise about "the skill of figuring out how to get what you want" to the new idea about "getting whatever you want instantly." Suppose you get whatever you want instantly. In that case, are you ever going to need to figure out how to get what you want? Of course not. So if it's true that skills are only acquired if you need them, then if you never need anything, you will never gain the skill of figuring out how to get what you want. Which of course means you will never acquire practical intelligence. In other words, if we add this answer choice to the argument, it makes the conclusion valid. So, it is correct.

Key Takeaway:
When there's a new concept in the conclusion of a Strengthen with a Sufficient Premise argument, this concept will almost certainly appear in the correct answer. The new concept may be slightly rephrased in the correct answer — like here, "need" isn't the same word as "never deprived of anything" — but the concept will be there nonetheless. You can't have a valid conclusion that depends upon a term detached from all the premises, so you need to connect that new term to a premise to validate the argument.

Sneaky trap answer! However, saying that deprivation is the "best" way isn't enough to guarantee that someone who gets everything they want instantly won't gain practical intelligence. Deprivation needs to be the only way to gain practical intelligence. Even if we add (C) to the argument, someone who given everything they want instantaneously could still develop practical intelligence. They may not take the "best" route to get there, but they could still get there. So (C) doesn't make this conclusion valid.

Even if practically intelligent people figure out how to get everything they want themselves, that doesn't necessarily mean that people given what they want instantly couldn't develop the skill of figuring out how to get what they want. In other words, practical intelligence may not be available exclusively to beings who already possess practical intelligence. So this answer choice is wrong because it doesn't guarantee that someone given what they want instantly will lack practical intelligence.

We're trying to prove that a person given everything they wanted couldn't develop practical intelligence. This answer choice is about a completely different, hypothetical person. It tells us that someone deprived of everything couldn't develop practical intelligence. Even if that were true, it wouldn't tell us anything about the person given everything they wanted.