Logical reasoning PrepTest 135 · Section 2 · Question 7

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
Babies don't have enough motor control to control the sounds they make. Kids are usually a few years old before they have the motor control for all language. Therefore, learning to talk is about motor control, not abstract/mental processes.

Answer Anticipation:
This argument shows that something is related to learning to talk (motor control), but it then concludes that learning to talk is just about motor control. This argument fails to consider that, while motor control is a limiting factor in talking, there could be other factors that are also limiting. After all, a baby isn't born understanding words and concepts—a lack of motor control isn't the only thing stopping them from making valid arguments.

In ignoring these other possibilities to reach a very strong and exclusionary conclusion, Gotera is ignoring these other potential factors. As such, the correct answer can take two tacks:
(1) Eliminate a single other consideration (e.g., abstract or mental processes that limit language)
(2) Eliminate all other considerations or establish motor control as the only consideration

Answer Explanation:
This answer eliminates all other considerations by establishing that motor control—the ability to produce the sounds of a language—is the only relevant factor in the ability to speak. If speech acquisition isn't a function of only the ability to make noises—if there are other factors—then the conclusion is contradicted.

Key Takeaway:
When an argument in a Strengthen with Necessary Premise question reaches an strong, exclusionary conclusion, the correct answer will usually eliminate other factors that the conclusion doesn't allow. That could be a single alternative factor; it could be every alternative factor.

Incorrect. The argument relies on babies not being able to voluntarily produce particular sounds. That's separate from intentionally moving their tongues, so this answer is out of scope—a baby could intend to move their tongue in a certain manner but not intend to make a certain noise.

Incorrect. There being a clear split between infancy, whatever's next, and the initial babbling stage isn't necessary for the argument to work. What's important is that that stage is solely related to motor control, not that it's over at a particular age.

Incorrect. If there's a stage before the initial babbling stage, the argument can still hold together as long as that stage also sees babies lacking motor control over the sounds they make.

Incorrect. This answer weakens the argument by bringing up something other than motor control that is a factor in speech.