LSAT PrepTest 44 Section 4 Question 14 Explanation | Logical Reasoning

I didn't write the following blog post. It was already on the blog when I took over the URL. The following blog post may contain mistakes. -Steve

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Here's a Logical Reasoning question from the October 2004 LSAT.

A chain of phrases (the bolding/underlining does it, but I'll write it out to be clearer) is useful:

P-fat helps eye-sight develop --> Formula = worse eye-sight --> Premature birth = worse eye-sight

We can't pre-phrase since any number of things might support the argument, so let's jump right into the choices:

A) Out of scope. This argument's about the development of eye-sight, not eye-sight in adults, which is fully developed.

B) Correct. This tells us that premature babies would have much less p-fat than normal babies. The argument says premature babies have worse eye-sight than normal ones, and with them having less p-fat as this choice says, that would suggest that p-fat is the cause of their less developed eye-sight. This supports the argument's contention that p-fat influences the development of eye-sight.

C) Out of scope. This argument is not about heredity but about the baby's exposure to p-fat. Whether visual acuity is or isn't heritable is immaterial here.

D) Out of scope, again. Infants might prefer the mother's milk for many reasons that might have nothing to do with an ability to detect (and a preference for) p-fat. And even if infants did prefer p-fat, that doesn't mean it enhances eye-sight, as the argument claims.

E) Out of scope once again. Whether or not eye-sight develops late in pregnancy may or may not have any relation to p-fat levels, which is what this argument's about.

Remember:

1) Use a chain of phrases and don't worry about making a pre-phrase if there isn't a definite answer, as is the case here.

2) Eliminate choices beyond the argument's scope. If they don't have anything to do with the argument, they can't support it.