Q9 - The brain area that enables one to distinguish

[ohthatpatrick]

Question Type:
Flaw

Stimulus Breakdown:
Conclusion: Practicing/playing a musical instrument actually alters brain structure.
Evidence: Correlation between playing a musical instrument and having a larger section of brain area that helps one distinguish different sounds made by a piano.

Answer Anticipation:
CORRELATION language in the Premise?
(Ppl who are X tend to be more Y than people who aren't)
CAUSAL language in the Conclusion?
(Playing an instrument ALTERS brain structure)

Why it's our good buddy, the Correlation vs. Causality flaw.
We debate these arguments by thinking:
1. Is there some OTHER WAY to explain the background fact, that there's a correlation between playing an instrument and having a bigger piano-area in your brain? (most common ways: Reverse Causality / Some Third Factor)
2. How PLAUSIBLE is the author's story, that playing an instrument changes your brain structure? (most common form of this is Covariation ... "the more people play, the more their brain was changed", "when people stop playing, their brain goes back to a normal shape")

In this case, Reverse Causality seems like a very likely contender. The author thinks that FIRST I started playing an instrument, THEN my brain area for piano enlarged. What if FIRST I was born with an enlarged brain area for piano, and THEN it made me more likely to want to play an instrument?

Correct Answer:
B

Answer Choice Analysis:
(A) The argument never distinguishes between highly skilled musicians and highly skilled pianists, so the author didn't need to make any assumptions regarding that distinction.

(B) YES, reverse causality. Brain area came first, playing the musical instrument came second.

(C) The conclusion isn't broader. It's still about instruments and brain structure. The evidence was about people who play musical instruments frequently vs. infrequently and specific part of their brain structure. The conclusion just causally links those two things, but it's not a broader range of phenomena.

(D) I don't think the author failed to address that possibility. His correlation makes it seem like if you never/rarely played an instrument, you will GENERALLY have a smaller brain area for differentiating piano sounds. The author seems to directly acknowledge this possibility.

(E) Hmm. It DOES seem like the author makes that rather obvious assumption. This may be a rare case where an answer choice points out a valid assumption, but not one we would think to criticize. The correlation compares "highly skilled musician" to "someone who has rarely, if ever, played a musical instrument". Is that 2nd group really "musicians"? There might be people who fancy themselves musicians, but it's a common sense stretch to interpret "someone who has rarely, if ever, played a musical instrument" as a "musician". Hence, the author is never directly comparing highly skilled musicians to lower-skilled musicians.

Takeaway/Pattern: Before I pick an answer choice on Flaw, I ask myself:
1. Is this saying something accurate?
2. Is this really a complaint about the logical move from premise to conclusion?

#officialexplanation

[abrenza123]

You mentioned the plausibility of the argument and covariance - having a difficult time imagining an example of that in an argument and how to address, and what an answer choice would say to address that flaw. What is an example of covariance in an LSAT or flaw question/answer choice?

[ohthatpatrick]

Covariance is just a fancy name for:
cause, effect
no cause, no effect

Seeing covariance strengthens a causal hypothesis.

If I'm hypothesizing that the girls at this bar are rejecting me because I'm wearing a Yankees hat, I can test that:
If I take the hat off, do they stop rejecting me? (no cause, no effect?)

If taking the hat off results in different girl-behavior, then I have good reason to think that the hat WAS the causal difference maker.
If I take the hat off and the girls still reject me, then I know that the hat is not the reason (or at least not the only reason).

Consider this fake-but-inspired-by-real argument:
Prisoners who went on a healthier diet exhibited improved behavior three months later. Clearly, eating well leads to better behavior.

A correct answer on Flaw, inspired by covariation could say:
(A) takes for granted that the prisoners who were not on the healthier died did not also exhibit improved behavior three months later
or
(A) fails to consider that the prisoners who were not on the healthier diet exhibited similar levels of improved behavior three months later

Does that make sense?