A survey in a leading medical journal

Answer choices

1. A

   Not a Flaw1% picked this

   ignores anecdotal evidence and bases its conclusion entirely on

   This is a true description but not an objectionable description. We love our conclusions to be evidence-based, and scientific research is a stronger source of evidence than is anecdotal evidence.

   1%
2. B

   Bad Evidence Match2% picked this

   considers only surveys published in one particular

   This argument isn't based off only one journal's study. It says that "other surveys have confirmed these results". Honestly, even if the evidence were only based off one leading medical journal, that in and of itself isn't objectionable. What's objectionable to LSAT is the certainty with which author draw their causal conclusions. If one medical journal publishes data that shows that "people who eat lots of eggs have high cholesterol", we're totally allowed to say, "Thus, it may be that eggs increase our cholesterol". We're not allowed to say, "Thus, it must be that eggs increase our cholesterol."

   2%
3. C

   Correct79% picked this

   concludes merely from the fact that two things are correlated that one

   Why this is right

   Since this answer is structured, concludes merely from the fact that Y that X we know that Y should match the evidence and X should match the conclusion. Did the evidence say that "two things are correlated"? Yes, there's a correlation (a statistical association) between aerobic exercise and lower risk of lung disease. Does the conclusion act like "one of those things causes the other"? Yes, the conclusion is acting like "aerobic exercise caused the lower risk of lung disease", because it's saying that aerobic exercise had a significant beneficial effect on people's health (and the only available match for "beneficial effect on health" is the idea of "lower risk of lung disease").

   Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.

   79%
4. D

   Too Strong17% picked this

   presumes, without providing justification, that anyone who does not have lung disease is

   Since this answer begins with presumes / takes for granted / fails to establish, we treat it like Necessary Assumption. Did the author assume that every single person in the world that doesn't have lung disease is in good health? Heavens no. That's an absurd claim. That would be saying that people with lupus, with covid, with malaria, with a flesh-eating bacteria are all in good health (as long as they don't have lung disease). The author presumes that something that has lowered one's risk of lung disease has had a beneficial effect on overall health.

   17%
5. E

   Not an Objection1% picked this

   fails to consider that even infrequent aerobic exercise may have some beneficial effect

   Since this answer begins with fails to consider / overlooks the possibility, we treat it like Weaken and ask ourselves if this would be a good objection to the argument. Can we hurt the author's argument by saying that "infrequent aerobic exercise may have some beneficial effect on people's health"? No. The author didn't say "only frequent aerobic exercise has any beneficial effect on health", so we're not disagreeing with him at all by saying "infrequent aerobic exercise could sometimes have some beneficial effect".

   1%