LSAT Explanation PT 40, S1, Q6: Skeletal remains of early humans indicate

LSAT Question Stem

Which one of the following, if true, most strengthens the argument? 

Logical Reasoning Question Type

This is a Strengthen question. 

Correct Answer

The correct answer to this question is E. 

LSAT Question Complete Explanation

First, let's summarize and analyze the argument in the passage. The passage states that skeletal remains show early humans had fewer dental problems than we do today. Based on this, the author concludes that the diet of early humans must have been very different from ours. The structure of the argument is as follows:

Premise: Early humans had fewer dental problems than we have.

Conclusion: The diet of early humans was very different from ours.

To make this argument more understandable, let's use a simple example: Imagine you find two groups of cars, one with fewer flat tires than the other. You might conclude that the roads these two groups of cars drove on were very different, perhaps one group drove on smoother roads than the other.

An "Evaluate" question for this argument would be: "Is there a strong connection between diet and dental health?"

Now, let's discuss the question type and what it is asking us to do. This is a Strengthen question, which means we need to find the answer choice that provides additional support for the conclusion in the passage.

a) A healthy diet leads to healthy teeth.

This answer choice is tempting but not quite right. While it states that a healthy diet can lead to healthy teeth, it doesn't provide evidence that early humans' diet was healthier or different from ours. The conclusion is about the difference in diets, not necessarily about the healthiness.

b) Skeletal remains indicate that some early humans had a significant number of cavities.

This answer choice actually weakens the premise of the argument, as it suggests that some early humans did have dental problems. This doesn't help strengthen the conclusion that their diet was different from ours.

c) The diet of early humans was at least as varied as our diet.

This answer choice implies that early humans' diet was similar to ours, which contradicts the conclusion that the diet was different. This doesn't strengthen the argument.

d) Early humans had a shorter average life span than we do, and the most serious dental problems now tend to develop late in life.

This answer choice provides an alternative explanation for the fewer dental problems in early humans - they didn't live long enough to develop them. This weakens the conclusion and doesn't help strengthen the argument.

e) Diet is by far the most significant factor contributing to dental health.

This is the correct answer choice. If diet is the most significant factor affecting dental health, it strengthens the connection between the observed fewer dental problems in early humans and the conclusion that their diet was different from ours.