Sociologist: The claim that there is a large number of violent crimes in our society is false, for this claim is based upon the large number of stories in newspapers about violent crimes. But since violent crimes are very rare occurrences, newspapers are likely to print stories about them.

Summarize Argument: Counter-Position
The sociologist concludes that it is false that there is a large number of violent crimes. The sociologist supports this conclusion by proposing an alternative explanation for the large number of newspaper stories about violent crimes: because violent crimes are rare, newspapers are more likely to print stories about them when they happen.

Identify and Describe Flaw
This is a cookie-cutter “circular reasoning” flaw, where to support the conclusion, the argument uses a premise that already assumes the conclusion is true. Specifically, the sociologist claims as a premise that violent crime is rare, in order to provide support to the conclusion that violent crime is rare.

A
presupposes that most newspaper stories are about violent crime
The sociologist doesn’t make any claims about whether most newspaper stories are about violent crime, only that there are many newspaper stories about violent crime.
B
presupposes the truth of the conclusion it is attempting to establish
The argument presupposes the truth of violent crime being rare, using this claim as a premise to support the conclusion that violent crime is rare. The conclusion is already presupposed to be true through the premise, making this a circular argument.
C
assumes without warrant that the newspaper stories in question are not biased
The sociologist does not make any claim of whether the newspaper stories about violent crime are or aren’t biased. Bias just isn’t part of the sociologist’s argument.
D
mistakes a property of each member of a group taken as an individual for a property of the group taken as a whole
The properties of members of a group and that group as a whole are not being discussed, so this isn’t relevant to the sociologist’s argument.
E
uncritically draws an inference from what has been true in the past to what will be true in the future
The sociologist is not comparing the past to the future. The argument only deals with the current state of violent crime and newspaper articles about violent crime.

37 comments

Because quitting smoking is very stressful and leads to weight gain, it is difficult to do. The key to quitting, however, may be as simple as replacing an unhealthy activity with a healthy one. In one study, half of those attempting to quit were assigned to a smoking-cessation program alone, and the other half were assigned to the same program plus fifteen weeks of aerobic exercise. At the one-month mark, none in the first group had quit, but 40 percent of those in the second group had not smoked.

A
Regular exercise prevents weight gain.
Aerobic exercise helps stave off one negative consequence of quitting smoking. This supports the idea that picking up exercise helps people quit smoking.
B
Each group in the study included four hundred randomly selected participants.
The study had a solid sample-size. Works for us.
C
Nonsmokers accustomed to regular exercise do not gain weight when they stop exercising.
We don’t care about nonsmokers. We care about how exercise can help smokers quit smoking.
D
Aerobic exercise can stimulate the brain’s production of endorphins, which reduce tension.
Exercise helps diminish tension, which is a negative side effect of quitting smoking. This supports the idea that picking up exercise helps people quit smoking.
E
Of those in the second group in the study, 38 percent had not smoked at the one-year mark.
The people who quit smoking didn’t relapse later on. Thus, exercise was indeed helpful for quitting smoking.

37 comments

A group of unusual meteorites was found in Shergotty, India. Their structure indicates that they originated on one of the geologically active planets, Mercury, Venus, or Mars. Because of Mercury’s proximity to the Sun, any material dislodged from that planet’s surface would have been captured by the Sun, rather than falling to Earth as meteorites. Nor could Venus be the source of the meteorites, because its gravity would have prevented dislodged material from escaping into space. The meteorites, therefore, probably fell to Earth after being dislodged from Mars, perhaps as the result of a collision with a large object.

Summarize Argument
The author concludes that a group of unusual meteorites found in Shergotty, India probably came from Mars. As support, the author says that the structure of the meteorites suggests that they came from Mercury, Venus, or Mars. Any material from Mercury would have been captured by the Sun and any material from Venus would not have escaped into space, which leaves Mars as the likely source of the meteroites.

Describe Method of Reasoning
The author’s argument works by laying out three possible options (Mercury, Venus, and Mars), and eliminating two of the options (Mercury and Venus), leaving Mars as the likely source of the meteorites.

A
offering a counterexample to a theory
The author does not offer a counterexample. Instead, the author outlines a question (the origin of the unusual meteorites) and makes a conclusion about the answer to this question (that the meteorites probably came from Mars).
B
eliminating competing alternative explanations
The author’s argument works by eliminating Mercury and Venus as potential alternate explanations of the origin of the meteorites.
C
contrasting present circumstances with past circumstances
The author does not contrast present circumstances with past circumstances; there is no distinction between how things are now and how things were in the past.
D
questioning an assumption
The author does not question any assumptions. Instead, the author lists Mercury and Venus as two of the possible sources of the meteorites because of the meteorites’ structure, then explains that material from Mercury and Venus would not have reached Earth.
E
abstracting a general principle from specific data
The author does not discuss any general principles, nor does the author mention specific data.

3 comments

All people prefer colors that they can distinguish easily to colors that they have difficulty distinguishing. Infants can easily distinguish bright colors but, unlike adults, have difficulty distinguishing subtle shades. A brightly colored toy for infants sells better than the same toy in subtle shades at the same price.

Summary
All people prefer colors that they can easily distinguish. Infants can easily distinguish bright colors, but have difficulty distinguishing subtle shades. Brightly colored toys for infants sell better than toys in subtle shades at the same price.

Strongly Supported Conclusions
Infant toy sales reflect the preferences of infants.

A
Infants prefer bright primary colors to bright secondary colors.
This answer is unsupported. We don’t know from the stimulus whether infants are able to distinguish between primary and secondary colors. We only know that infants are able to distinguish between bright and subtle colors.
B
Color is the most important factor in determining which toys an infant will prefer to play with.
This answer is unsupported. To say that color is the “most important factor” is too strong. Color is an important factor for infants, but we don’t have enough information to conclude that it is the most important factor.
C
Individual infants do not have strong preferences for one particular bright color over other bright colors.
This answer is unsupported. The stimulus addresses the preferences of infants generally. We don’t know about any individual infant’s preferences from the stimulus.
D
The sales of toys for infants reflect the preferences of infants in at least one respect.
This answer is strongly supported. We know that infants prefer bright colors and we know that brightly colored toys sell better. Therefore, it’s likely that this preference for bright colors affects the toy sales for infants.
E
Toy makers study infants to determine what colors the infants can distinguish easily.
This answer is unsupported. Nothing in the stimulus addresses the toy maker’s perspective.

34 comments