LSAT Explanation PT 39, S4, Q1: A study comparing infant care revealed

LSAT Question Stem

Which one of the following statements, if true, most seriously weakens the argument? 

Logical Reasoning Question Type

This is a Weaken question. 

Correct Answer

The correct answer to this question is E. 

LSAT Question Complete Explanation

Let's first analyze the argument in the passage. The passage presents a study that shows a correlation between the amount of stimulation babies receive and their sleep. It states that babies with a less stimulating daytime routine sleep an average of two hours more per day than those with a more stimulating routine. The passage then concludes that since sleep plays an important role in a child's development, parents would be wise to reduce the amount of stimulation their babies receive.

Here, we have two premises:

1. Babies with a less stimulating daytime routine sleep more.

2. Sleep plays a very important role in a child's development.

And the conclusion is:

Parents would be wise to reduce the amount of stimulation their babies receive.

The question type is Weaken, which means we need to find an answer choice that weakens the conclusion or the relationship between the premises and the conclusion.

An "Evaluate" question for this argument could be: "Does reducing stimulation have any other effects on a child's development?"

Now, let's go through the answer choices:

a) Babies' muscular coordination is unaffected by the amount of stimulation they receive.

This answer choice doesn't weaken the conclusion, as it merely shows that one aspect of a child's development (muscular coordination) is not affected by stimulation. It doesn't address the relationship between sleep and development or provide any reasons why reducing stimulation might not be wise.

b) Babies with less stimulating routines usually get extra sleep during the day.

This answer choice restates information from the passage (premise 1) and doesn't provide any new information that would weaken the conclusion.

c) Studies showed no correlation between stimulation and amount of sleep for children three years of age or older.

This answer choice is out of scope, as it discusses children who are older than the babies in the study. It doesn't address the relationship between stimulation and sleep for the babies in question and doesn't weaken the conclusion.

d) The babies who had a less stimulating routine gained weight at an average rate.

This answer choice doesn't weaken the conclusion, as it merely provides information about weight gain in babies with less stimulating routines. It doesn't address the relationship between sleep and development or provide any reasons why reducing stimulation might not be wise.

e) The stimulation that babies receive helps them to develop intellectually.

This is the correct answer because it introduces a competing concern: while reducing stimulation may lead to more sleep and better development in one aspect, it could also hinder intellectual development. This weakens the conclusion that parents would be wise to reduce the amount of stimulation their babies receive.

In conclusion, the correct answer is E, as it weakens the argument by introducing a potential downside to reducing stimulation in a baby's routine.