Self-study
Support In one study, hospital patients' immune systems grew stronger when the patients viewed comic videos. ████ █████████ ████ ████████ ███ ███ ████████ ████ ████████ ███ ████ ███████ █████ ██ ██████ ██████ ████████ ████████ ██ ███ ████████ █████ ████████ ██ █████ ███ ███████ ██ █████ █████ ██ ████████ ████████ ████ █ ███████ ████████ ██ █████ ███ ██████ ████ ██ █████ ████████ ████ ███████ ████ ████ ████ █████ █ ██████ ████ █████ ████████ ███ ██████ ████ ████ █████ █ ███████ ███████
Tendency vs. Amount of Laughter
The study found two things: (1) laughter can aid recovery, and (2) patients with a greater tendency to laugh had much greater immune system gains. From this, the author concludes that patients with a greater tendency to laugh benefit more from recovery even when they laugh only a little than other patients do when they laugh a lot. In other words, the author thinks there's something special about having the tendency itself, independent of how much you actually laugh.
But wait. The study just showed the comic videos to everyone and measured the results. We don't know how much each group actually laughed. And isn't it reasonable to think that people with a greater tendency to laugh probably laughed more while watching the videos? If so, the greater immune gains might just be because they laughed more, not because their underlying tendency gives them some extra boost.
Two Explanations for the Same Data
What the study found
High-tendency group
watched comic videos
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immune gain
Low-tendency group
watched comic videos
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immune gain
The high-tendency group gained more. But why?
Two competing explanations
Author's explanation — it's the tendency
High tendency, laughed a little
Low tendency, laughed a lot
The tendency itself provides a special boost.
Alternative — it's the laughter
High tendency, laughed more
Low tendency, laughed less
No special boost. They just laughed more.
Both explain the same data. The study didn't measure actual laughter, so we can't tell which is right.
The author jumps to "it's the tendency." But "it's the laughter" is just as (if not more) plausible an explanation for why those with a greater tendency to laugh saw greater immune gains.
7.
The argument is most vulnerable ██ █████████ ██ ███ ███████ ████ ██
a
overlooks the possibility ████ ███ ████████ █████ ████████ ██ █████ ███ ███████ ██ █████ ████ ███████ ████ ██ ███ █████ ██████ ████ ███ ███ █████ ████████
(A) identifies a possibility the author needed to address but didn't. If the high-tendency patients laughed more at the videos, then their greater immune gains might just be a result of more laughter, not some special property of their tendency. We'd have no reason to jump to the author's conclusion that tendency itself helps if the high-tendency group simply laughed more during the study.
b
fails to address ██████████ ███ ███████████ ████ ███ ████████ █████ ████████ ██ █████ ███ ████████ ██ █████ ████ ███████ ███ ████████ ██████ ███████ ████ ███ █████ ████████
Maybe the high-tendency group already had stronger immune systems before the study. But the study measured gains in immune system strength, not absolute levels. Even if one group started with stronger immune systems, what matters is whose immune systems grew more from watching the videos. Starting stronger doesn't explain gaining more.
c
presumes, without providing ██████████████ ████ ████████ ████████ ████ ██████ ███████ ██████████████ ██ █████ ██ ███ ██████ ██████████
The author's conclusion is about hospital patients, not the general population. She doesn't generalize beyond the group studied, so there's no need for hospital patients to be representative of everyone.
d
takes for granted ████ ███ █████ ██ ██████ ██████ ████████ ███ ███ ██████████ █████████ ███ █████████ ████████ ██ █████
This suggests that gaining immune strength might have changed patients' tendency to laugh. But the premise describes patients whose tendency to laugh was
e
presumes, without providing ██████████████ ████ ███ ████████ █████ ████████ ██ █████ ███ ████████ ██ █████ ████ █████████ ████ █████ █████████ ████ ███████ ████ ███ █████ ████████
The author doesn't assume that the high-tendency group recovered faster. The conclusion and the study are about who recovered more, not who recovered faster. These are different things. You can recover a large amount slowly or a small amount quickly. Speed of recovery isn't what's being measured or concluded.