LSAT 151 | Section 4 | Logical Reasoning: Q9

LR Question 9 Explanation

QUESTION TEXT: The brain area that enables one to distinguish the…

QUESTION TYPE: Flawed Reasoning

CONCLUSION: Practicing and playing a musical instrument changes brain structure.

REASONING: Part of the brain lets people differentiate piano sounds. This part of the brain is usually bigger in musicians than in non-musicians.

ANALYSIS: The flaw is that the argument presents a correlation and assumes it means causation. When there’s a correlation there are always four possibilities:

1. Skilled piano playing leads to a bigger brain area
2. A bigger brain area leads to people becoming good at music
3. Some other factor both leads to a bigger brain area and draws them to music. (I dunno….they listen to music when young, which enriches their brain and also sparks simultaneous musical interest?)
4. It’s a coincidence (this is rarely used on the LSAT, but common in real life correlations)

Since this is a flaw question, you can critique the argument simply by pointing out the alternate possibility. Usually it will be one of the first two. In this case, the argument uses #1, so expect to find #2 in the answers.

___________

1. Actually, the argument didn’t mention pianists. It said highly skilled musicians have a larger section of the brain: the section that does piano sensing. But this statement was about all musicians, not just pianists.
2. CORRECT. See the analysis above. This is possibility #2 in the correlation possibilities above. Maybe the larger brain section is what allows skilled musicians to be good at music. You see this often in sports: it is generally the genetically gifted who become the highest tier of elite athletes. Training doesn’t change your genes.
3. This is a different flaw. The range discussed wasn’t narrower: the argument talked about “all people”, and had evidence from all people: skilled musicians, and non-musicians. Example of flaw: Skilled pianists have long fingers. So, all skilled people of any type must have long fingers. [e.g. pianists are a narrow range, all people is broad]
4. Actually, I’d say the argument does address this. It says the part of the brain related to piano sounds is larger in musicians than in those who have only rarely played an instrument. That’s pretty similar to “people who never learned to play” an instrument. Maybe this answer is referring to another “certain area of the brain”, but I don’t see why that matters. To prove that practice can change the brain, a single area changing is proof enough. Other areas aren’t necessary.
5. The argument made no such comparison. It only compared skilled musicians to people who rarely or never played instruments.