#18 - An article claims that many medical patients have

[Nikki Siclunov]

The following analysis of Question #18 is in response to a question posted to our Blog:

Nikki - in real time, I would never be able to get the two ( #18 and 24) LR q's that you referenced above. It took me close to an hour just to unpack both questions. I had never seen anything like either before in any previous exam. Could you simplify or break down the structure for either of them so that the next time we are unfortunate enough to come across them, we can more readily recognize them? Thanks for the recap and for your time.

http://blog.powerscore.com/lsat/october ... g-overview

Hi Mariel,

Thanks for the question! Let's take a look at Question #18 first.

The stimulus contains an argument, and – as always – simplification is key. The author does not buy the rumor that patients can predict sudden changes in their medical status. Why is she so skeptical? Because she considers the rumor to be analogous to another, already disproven rumor, namely, that there are more babies born during full moons than at other times. The author points out that there is no correlation between busy maternity wards and full moons; the reason why we think there is one is that the busy nights with full moons are more memorable that the busy nights without them! In other words, a memorable coincidence creates an illusion that something special is actually happening.

Is the same illusory perception affecting our belief that patients can predict sudden changes in their medical status? The author assumes as much. The analogy can only pass muster if we assume that a patient’s correctly predicting a change in his medical status (a memorable coincidence) is more likely to be remembered by the medical staff than if the prediction wasn't correct, and no change occurred. Just like the medical staff is more likely to remember the busy nights with full moons, they should also be more likely to remember when the patient correctly predicts a change in his medical status. For the two rumors to be analogous, we need to assume that in both of them a memorable coincidence creates an illusion that is ultimately untrue.

This prephrase agrees with answer choice (B), which states that a patient’s prediction is less likely to be remembered if no change occurs (i.e. the prediction is inaccurate). The corollary to this statement is that a patient’s prediction is more likely to be remembered if it actually proves true. This is precisely what I was looking for. If answer choice (B) weren’t true, and the likelihood of remembering a patient’s prediction is not affected by whether or not the change actually occurs, then the two rumors would be materially different, and what makes one of them illusory may not apply to the other. Since the logical opposite of answer choice (B) weakens the conclusion, this answer states a claim upon which the conclusion depends.

I hope that makes sense. It’s a tough question for sure, so I’m glad you asked for an explanation.

[cecilia]

Thank you Nikki!! Awesome explanation.

Lingering question on (A), which I fell for. Had it not used the word "soon", could it have been correct?

[Ladan Soleimani]

Hi Cecilia,

Answer choice (A) can be tempting because the stimulus tells us that the case with babies being born in disproportionally high numbers on the full moon has already been disproven. It seems to make sense that if it is an analogous case, then patients being able to predict their medical status would also be disproven. However, it misses the main point of the analogous case, which is what Nikki has explained above. "The analogy can only pass muster if we assume that a patient’s correctly predicting a change in his medical status (a memorable coincidence) is more likely to be remembered by the medical staff than if the prediction wasn't correct, and no change occurred."

Remember, for an assumption question you are looking for what is required for the conclusion to be true. For this argument it is necessary that correctly predicted changes in medical status by patients are remembered more often, otherwise the analogy doesn't work and the argument falls apart. It is not necessary for this to be disproven 'soon' or ever. The Assumption Negation Technique might make this clearer. If you negate answer choice (A), to get that the article will not be empirically disproven, then it still doesn't weaken the argument. Just because the article is not disproved does not mean that the article is true and the argument still works. Would answer choice (A) be helpful to the author's argument? Yes, but it isn't required so it cannot be the assumption.

I hope that makes sense!
Ladan

[cecilia]

Thanks Ladan for the reinforcement! It helped a lot.

[emilysnoddon]

Why is D not an assumption of the argument?

[Clay Cooper]

Hi emily,

Thanks for your question.

Answer choice D is incorrect because the claim in it does not have to be true in order for the conclusion to be true. The conclusion is that the anecdotal evidence regarding predicting sudden changes in medical status should not be trusted.

Answer choice D states that babies are less likely to be born on a night with a full moon than on a night without a full moon. The author of this argument doesn't depend on this being true. In fact, I doubt he would agree with it; by bringing up the disproven reports of higher numbers of births on nights with full moons, he is just illustrating the same phenomenon he thinks is at work here: systematic biases in human memory.

Furthermore, negating answer choice D would yield a claim that it is not the case that babies are less likely to be born on a night with a full moon than on a night with a less than full moon. This statement, if true, does not attack our conclusion; thus, the negation technique warns against choosing D.

[blade21cn]

I know I'm falling into LSAC's trap here, but am seeking a better understanding to hopefully prevent this from happening again. I understand the author's argument by way of analogy that because A shares similarity with B in the first characteristic, A must share similarity with B in the second characteristic.

Specifically, A is the claim in an article that "many medical patients have an instinctual ability to predict sudden changes in their medical status." B is the reports that "babies are born in disproportionately high numbers during full moons." B's first characteristic is "maternity room staff were more likely to remember busy nights with full moons than busy nights without them." B's second characteristic is "such reports were empirically disproven."

The author wants to use B's second characteristic to prove his conclusion that the patients instinct claim should not be trusted. In order for the argument to stand, the author assumes that A also shares B's first characteristic in that medical staff were more likely to remember incidences where the patients' prediction is right than when they're wrong, which is what (B) says.

My question is B's first characteristic also has a condition attached - "Once that rumor became popular." I can comprehend, as Nikki perfectly put it, how a memorable coincidence can create an illusion, but with the condition it made me feel that it is this "popular rumor (a widely held belief)" that somehow created this psychological effect that made people associate these two irrelevant things together, namely "babies being born" and "full moons." This thinking landed me perfectly on (E) that says this rumor is not yet a widely held belief. Only in this circumstance, once becoming popular, this rumor will start this chain reaction and meet its final fate. But in retrospect, I think this condition does nothing to the rationale that a memorable coincidence can create an illusion. In other words, it is the human nature that we tend to associate two things together when we felt it's somehow a miracle, regardless of what other people say, i.e., a popular rumor/widely held belief. But if it's human nature, why do we have to assume it's the case, because IT IS the case? It is a fact.

[Brook Miscoski]

blade21,

I believe you're suggesting that if the "rumor" about predicting changes in one's health hasn't become widespread, then maybe people aren't yet paying attention to it. That would introduce a dissimilarity into the analogy, so the stimulus needs a supporter/defender to address that. I agree with your basic reasoning.

The issue with (E) is that we are doing an assumption question, not a weaken question. Choice (E) does nail the issue you've described, but unfortunately it does so by stating that the assumption is false rather than by establishing the assumption as true. Therefore, (E) accomplishes the wrong task.

Choice (B), on the other hand, skips over the question of what's driving the attention and simply states that medical staff are less likely to remember that a prediction occurred if the prediction is incorrect. While it doesn't complete the analogy in exactly the way that you were expecting, it does defend against the dissimilarity by showing that the main gist of what you call part B is preserved--medical staff are simply more likely to remember the prediction/busy night when it aligns with being correct/full moon.

Your remaining question about the nature of assumptions can be addressed as follows. The missing part of the analogy, whether or not it is a true fact about the universe, is still missing and therefore assumed. There is zilch about assumptions that requires them to be possibly false. If your argument rests on an unstated claim or fact, that's an assumption, even if everyone knows it is true. So don't get trapped into thinking that because you agree with the unstated portions of an argument that nothing is being assumed.

[lanereuden]

So I thought it was D because if you negate it you get:
Babies are more likely to be born during full moon night than non full moon night. Thereby proving the argument which was “disproven”

[lanereuden]

Also it seems the assumption here is not about connecting a gap between premise and conclusion, As it normally is on these necessary assumption questions


Instead, it is about ensuring the parallel reasoning structures match up exactly...like:

I have a dog, and it’s name is Joey
All Dog has four legs
Joey has four legs

This is akin to my brother who has cat, named Jack.
Therefore, Jack has four legs.

What’s missing in this parallel reasoning? All cats have Four legs too.


Is this correct/simple way to think about it?

(I guess this too matches up gap in premise and conclusion, it’s just that, in doing so, it also fixes parallel reasoning problem too....is this the more accurate worldview? )