Logical reasoning PrepTest 114 · Section 1 · Question 24

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
1yo - Prefer sweet to salty
Feed a 1yo salty foods for a years → That 2yo prefers salty food
Therefore - The food a kid eats affects their taste preferences

Answer Anticipation:
This argument has a conclusion that talks about one thing being affected by another—that's a causal conclusion. Whenever any argument has a causal conclusion, you should start off considering a correlation/causation flaw.

So is the premise a correlation? It is. While it can easily be read as a causal relationship between feeding a kid salty foods and changing their preferences, it's not causal. It's a conditional ("if"), and conditionals present correlations, not causal relationships. We know—this conditional is phrased very well to make it sound causal, but there's no causal language used.

As such, this argument features a Correlation/Causation flaw. When that happens in a Strengthen with Necessary Premise question, the correct answer usually rules out an alternative cause (or coincidence, or reversed causality). Let's head down and find an answer that does so

Answer Explanation:
If 2yo naturally prefer salty foods to sweet foods, then it wasn't the year of feeding them salty foods that affected their preferences—they just naturally changed with age. This answer rules out an alternative cause (a natural shift in taste preferences), so it's the correct answer.

Key Takeaway:
We want to focus on answer choice (C) here, as these answers that are very complex and have multiple negations in them can be difficult to parse. For many of them, cutting out the additional clauses for an initial read can be a good way to see if they're directionally correct or in scope. Here, no matter what the ends of the answer stated, the core of it, when negated, helped the argument, and the extra information couldn't change that.

Incorrect. This answer doesn't speak to the cause of that change, which is what the argument is about. And, in fact, if the taste preferences naturally change between 1 and 2 instead of changing just for those who are fed non-sweet foods, that undermines the argument!

Incorrect. This answer is unbelievably hard to understand on reading with all of the negatives in it! Let's shorten it to focus on the key concept—2yo don't naturally dislike salty foods a lot. If we test that by negating it, it'd say that 2yo do naturally dislike salty foods a lot, and if that's the case, then the 2yo that have been fed salty foods liking salty foods suggests that something caused them to overcome their natural dislike for them. That strengthens the argument that it was the diet they were fed that did so by ruling out an alternative (a natural shift towards liking salty foods). When the negation of an answer strengthens the argument, it's not a necessary premise.

Incorrect. There's no indication that this is a requirement for those foods, so this answer is out of scope.

Incorrect. What is better for them is out of scope since the argument is about only their taste preferences.