A threshold problem with the argument is that it assumes that what improves memory and
learning in rats will also improve memory and learning in humans. Although this is entirely
possible, the argument provides no evidence to support this assumption. Without such
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evidence the argument can be rejected out of hand.
A second problem involves the fact that PEP increasingly breaks down the chemicals
needed for learning and memory as humans age--as the argument points out. Yet the
argument seems to daim that inhibiting PEP will be effective in improving learning and memory
in young people. (The argument refers to students’ "parents," implying that proposed human
subjects are young people rather than adults.) Thus the effectiveness of the compounds is
likely to be far less significant than it would be for older people.
A third problem with the argument is that it assumes that learning and memory are the only
significant factors affecting performance in school. Common sense and experience tells us this
is not the case, and that a variety of other factors, such as motivation and natural ability, also
play major roles. Thus the compounds might very well turn out to be largely ineffective.
A final problem with the argument is that it asserts that the compounds will improve
concentration, yet it makes no claim that the same compounds improved concentration in
rats----only that they improved the rats’ learning and memory. Thus the argument’s conclusion
is indefensible to this extent.
In sum, the argument is weak on several grounds. To strengthen it the argument’s
proponent must provide clear evidence that the same compounds that improved learning and
memory in rats will do so in young humans. Moreover, the argument’s proponent must show
that poor academic performance is due primarily to learning and memory problems, rather
than to poor concentration, motivation, or other factors.Argument 49
In a study of reading habits of Leeville citizens conducted by the University of Leeville, most
respondents said they preferred literary classics as reading material. However, a follow-up
study conducted by the same researchers found that the type of book most frequently checked
out of each of the public libraries in Leeville was the mystery novel. Therefore, it can be
concluded that the respondents in the first study had misrepresented their reading habits.
This argument concludes that in a certain study about reading habits Leeville citizens
misrepresented their true reading habits. To justify this conclusion, the argument points out an
apparent discrepancy between their representations and the results of a follow-up study
showing that a different type of book is the one most frequently checked out from Leeville’s
public libraries. However, the argument fails to account for several other possible explanations
for this apparent discrepancy.
First of all, the argument does not indicate how much time passed between the two studies.
During a sufficiently long interim period the demographic makeup of LeeviUe might have
changed, or the reading habits of the first study’s respondents might have changed. In other
words, the longer the time between studies the less reliable the conclusion that respondents in
the first study misrepresented their reading habits.
Secondly, the argument fails to account for the possibility that the respondents in the first
study constitute a different population than public library patrons. Admittedly, both groups are
comprised of Leeville citizens. However, it is entirely possible that more highly educated
citizens who frequent the University library rather than public libraries, or who purchase books
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rather than borrow them, are the ones who responded to the first study.
Thirdly, the argument fails to account for the possibility that literary classics, the book type
that the first study’s respondents indicated they preferred, are not readily available at
LeeviUe’s public libraries---or at least not as readily available as mystery novels. Experience
informs me that this is likely, because mystery novels are in greater supply and are cheaper for
libraries to acquire than literary classics. If this is the case, it provides an alternative
explanation for the fact that more mystery novels than literary classics are checked out from
Leeville’s public libraries.Finally, the reliability of the first study rests on its statistical integrity. The argument fails to
indicate what portion of the people surveyed actually responded; the smaller this portion, the
less reliable the results. Nor does the argument indicate how many people were surveyed, or
whether the sample was representative of Leeville’s general population. Again, the smaller the
sample, the less reliable the results.
In conclusion, the assertion that respondents in the first study misrepresented their reading
habits is untenable, in light of a variety of alternative explanations for the apparent discrepancy
between the two studies. To strengthen the argument, its proponent must show that the
respondents in the first study are representative of Leeville citizens generally, and that both
groups are equally likely to check out books from Leeville’s public libraries. To better evaluate
the argument, we would need to know the length of time between the two studies, and whether
any significant demographic changes occurred during this time. We would also need to know
the availability of literary classics compared to mystery novels at Leeville’s public libraries.
Argument 50
A recent study shows that people living on the continent of North America suffer 9 times more
chronic fatigue and 31 times more chronic depression than do people living on the continent of
Asia. Interestingly, Asians, on average, eat 20 grams of soy per day, whereas North Americans
eat virtually none. It turns out that soy contains phytochemicals called isoflavones, which have
been found to possess disease-preventing properties. Thus, North Americans should consider
eating soy on a regular basis as a way of preventing fatigue and depression.
This argument condudes that North Americans should eat soy on a regular basis as a
means of preventing fatigue and depression. The argument cites a recent study showing that
North Americans suffer far greater from these problems than people in Asia do, that Asians eat
soy regularly whereas North Americans do not, and that soy is known to possess
disease-preventing properties. The argument relies on several doubtful assumptions, and is
therefore unconvincing.