#7 - In one study, hospital patients’ immune systems

[Administrator]

Complete Question Explanation

Flaw in the Reasoning—CE. The correct answer choice is (A)

This stimulus discusses a study that looked at the relationship between laughter and the human immune system. In the study, hospital patients watched comic videos. When they watched these videos, their immune systems grew stronger, which the author claims is an indication that “laughter can aid recovery from illness.”

Not all of the patients had identical results, though. Those patients who had a greater tendency to laugh in the first place (what we will call the "frequent laugher" group) showed much greater gains in their immune systems. Based on this differing result, the author suddenly concludes that a patient who has a greater tendency to laugh will get more help in their recovery from even a little laughter than will a patient who does not have as great a tendency to laugh but in fact laughs more. This conclusion is problematic because we can't make a relativistic judgment here: there is no information suggesting that frequent laughers who laugh just a little will benefit more than less frequent laughers who laugh a lot.

This is a Flaw question. Our prephrase is that the author lacked the evidence necessary to reach the argument’s comparative conclusion.

Answer choice (A): This is the correct answer choice, since it points out that the argument does not provide evidence of the patients’ actual laughter. It very well may be that the patients with a greater tendency to laugh (the frequent laughers) actually laughed more when watching the videos. The author presented no evidence concerning how much the patients actually laughed, and so there is no support for the conclusion comparing the tendency to laugh and actual laughter as competing causes.

Answer choice (B): While it is true that the argument did not address the relative strengths of the patients’ immune systems to begin with, that comparison is irrelevant to the conclusion, which focused on the differences in their gains and not the absolute strength of their immune systems.

Answer choice (C): The argument made no mention of the “entire population.” This answer choice would be applicable if the argument took evidence regarding the patients’ immune systems and applied that data to a conclusion about the immune systems of the entire population, which the argument did not do.

Answer choice (D): This answer choice can be tricky, but it has to do with an error in causal reasoning and would be applicable if the conclusion improperly inferred causation based on a correlation between an increase in the patients’ immune system and an increase in their tendency to laugh. However, the conclusion did not mention an increase in their tendency to laugh, but rather compared those with a higher tendency to laugh to those with a lower tendency to laugh. If the strengthening of the immune system made the patient more likely to laugh, then based on the context of the stimulus, the more the patient’s immune system improved, the more the patient would be likely to laugh.

Answer choice (E): Although the conclusion did state that those with a higher tendency to laugh were helped more in their recovery, the argument did not assume that those patients recovered more rapidly.

[Basia W]

Hello,

the answer choice to this question took me by surprise. I chose E thinking that it was more relevant to the conclusion. Thank you for explaining the correctness of answer choice A!

Best,

Basia

[David Boyle]

Hello,

the answer choice to this question took me by surprise. I chose E thinking that it was more relevant to the conclusion. Thank you for explaining the correctness of answer choice A!

Best,

Basia

Hello Basia,

The stimulus says nothing about recovering rapidly, so answer E is out.
Answer A riffs on the stimulus saying the patients with a previous tendency to laugh more, "laugh a little" when seeing the comic videos. But how do we know that? Answer A says that maybe they actually laugh a lot when seeing the videos, which badly hurts the argument in the stimulus.

Hope this helps,
David

[ehilliard]

Could you explain the error with B on this question? I took B to provide an alternate cause.

[David Boyle]

Could you explain the error with B on this question? I took B to provide an alternate cause.

Hello ehilliard,

That may be a tempting idea, but just those with the "strongest laughing tendency" to start with also had a stronger immune system to start with, that does not really explain the "greater gains in immune system strength" that occur. It might make it even harder, since if they had such a great immune system, how much could they really improve?
Also, answer B doesn't really deal with the "laughs a little vs. a lot" discrepancy.

Hope this helps,
David

[mpoulson]

Hello,

Despite reading the analysis above, I still find A troubling. The stimulus explicitly states in the conclusion that those those with a greater tendency to laugh, laughed a little and those who didn't laughed a lot. However, A is saying that this isn't happening. Is the conclusion simply an mistaken assumption the author is making and not the truth? Thank you.

V/r,

Micah

[Clay Cooper]

Hi Micah,

Thanks for your question.

You are exactly right; the author is mistakenly assuming in the conclusion that those with a greater tendency to laugh only laughed a little in the experiment. That information is not given to us in the evidence, and thus to conclude that it is true creates the flaw in this argument.

Keep working hard!

[MikeRov25]

I understand how A is correct, but what kind of false reasoning is this? I've looked through my book and cannot find anything similar.

[Adam Tyson]

Hey Mike, the argument here is causal, but the flaw seems to be an evidence flaw. It's not about alternate cause or any of the other causal errors. Instead, the problem is a lack of relevant evidence. Nowhere in the stimulus do we get any information about variations in the amount of laughter, only about differences in the gains made by two groups - those that already had a tendency to laugh a lot got bigger gains than those that did not have that tendency. Since there was no evidence about the amount of laughter in the study, the conclusion about variations in that amount is without any support at all.

[ibarrajo]

This question literally gave me a headache so I took some time off to cool down. After an hour, I returned to the problem and noticed something that I had overlooked. The issue here, to me, lies in the conclusion, particularly in the part now bolded: "So hospital patients with greater tendency to laugh are helped more in their recovery from illness even when they laugh a little than other patients are helped when they laugh a greater amount"

Specifically, this part isn't supported by the premises. From the study, we can assume that patients laughed after watching the videos. Fair enough. However, from this finding alone the author then concludes that those with a tendency to laugh, even when they laugh a little, are helped more in their recovery than those who laugh and laugh and laugh. This is a stretch by any means and would need more supporting evidence to be a sound conclusion. Therefore, to answer the question, what if those with a tendency to laugh actually laughed more during the study? Wouldn't this support the idea that laughing more, regardless of the tendency at the onset, is what matters NOT the tendency of in itself. This would suggest that we cannot conclude that less laughter from a person with a tendency to laugh trumps a person without such tendency that laughs much more, considering that this wouldn't be supported by the study.

That's how I'm reasoning this problem and how I came to terms with the answer choice. Frankly, the explanation at the beginning of this thread confused me so I couldn't see this reasonsing right away. Hope this helps anyone that was still unsure!