LR Question 5 Explanation
QUESTION TEXT: Researchers announced recently that over the past 25…
QUESTION TYPE: Weaken
CONCLUSION: Sunscreen isn’t likely to reduce skin cancer.
REASONING: Skin cancer has grown even though more people are using sunscreen.
ANALYSIS: This is a bad argument. People might be using sunscreen because they’re out in the sun. Sunscreen could reduce their risk of skin cancer, even if it can’t totally offset the increased exposure.
I checked the answers, and noticed that my prephrase wasn’t there. Who cares? It could have been the answer, but I didn’t get attached to it. Prephrasing is extremely valuable, but don’t get stuck on a single explanation.
The correct answer weakens the argument by pointing out that cancer takes decades to develop. So the current cancers developed before sunscreen use was common, and sunscreen might still be effective.
Small public service announcement: sunscreens focus on SPF, which is UVB. But UVA is the main cause of melanoma. Check whether your sunscreen blocks both UVA and UVB.
___________
- It’s not clear why the most expensive brand matters.
- CORRECT. This shows that current skin cancer had its origins a long time ago, before the recent increase in sunscreen use.
- It’s good that sunscreens are based on research. But this can’t weaken the fact that cancer rates are increasing.
- This doesn’t tell us anything about sunscreen.
- I can see how this is tempting. This would be the right answer, if the argument had said:
“Sunscreen doesn’t help. Those who use sunscreen are just as likely to get cancer.”Then this answer would show that the cancer group had a higher risk, and sunscreen may have lowered their risk.
But the argument was different! It said we have more cancer even though we use more sunscreen.
So the question is: why hasn’t increased sunscreen use reduced cancer on average? If sunscreen was protective we would expect rates to go down if more people use it.
Recap: The question begins with “Researchers announced recently that”. It is a Weaken question. To practice more Weaken questions, have a look at the LSAT Questions by Type page.
More Resources for Weaken Questions
- Intro Course lesson: This intro course lesson covers Weaken questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers weaken questions.
Hi,
I am confused by your explanation of why answer choice “D” is incorrect, especially because the correct answer choice “B” also does not explicitly mention sunscreen. Could you go more into detail as to why D does not work? Thanks!
In the answer explanations, it’s explained D is incorrect because “it doesn’t tell us anything about sunscreen”. This doesn’t mean that the answer choice needs to specifically mention the word “sunscreen” to be correct. For weakening questions, you need to identify the conclusion, and then choose an answer choice that directly counters the conclusion. We need something that disputes the fact that sunscreen’s unlikely to reduce skin cancer. B does just that. We’re told that sunscreen’s been widely used for the past 25 years, but nothing beyond that. It could be that 26 years ago, no one at all used sunscreen. So old people, who were young more than 25 years ago, probably didn’t use sunscreen, and thus developed skin cancer. This casts doubt on the argument’s conclusion and says that rather than sunscreen being ineffective, it’s probably that people just didn’t use it. So the important distinction here is that B addresses something related to possible past sunscreen use, whereas D applies to anyone at risk, whether or not they use sunscreen.
I think “over the past 25 years” in the premise and “is unlikely…developing” in the conclusion are clues for pre-phrasing. Maybe it takes more than 25 years to develop skin cancer.
For answer choice E, I found it helpful comparing PT64 sec 1 No.13. It illustrates a case where answer choice like E might be a correct answer. But I think E has two other weaknesses. First, it talks about people who “most” regularly use sunscreens, which is a very limited group of people within people who use sunscreens, and this makes this choice very weak to weaken. Second, it talks about people who “believe” themselves to be most susceptible to skin cancer. This is different from what actually is and also makes this choice very weak.