Summarize Argument: Phenomenon-Hypothesis
The author concludes early humans had different diets than us. Her evidence is that skeletal remains of early humans show fewer dental problems than we have.
Notable Assumptions
The author assumes that virtually the only thing that could’ve caused fewer dental problems in early humans is different diets.
A
A healthy diet leads to healthy teeth.
We have no idea if early humans or modern humans have “healthy diets.”
B
Skeletal remains indicate that some early humans had a significant number of cavities.
Regardless, early humans had less dental problems than we do now.
C
The diet of early humans was at least as varied as is our diet.
We don’t care how varied their diet was. We need to strengthen the connection between early humans eating a different diet than ours, and early humans having less dental problems than us.
D
Early humans had a shorter average life span than we do, and the most serious dental problems now tend to develop late in life.
This weakens the author’s argument. Early humans had fewer dental problems because they didn’t live long enough to develop such problems, rather than because of their diets.
E
Diet is by far the most significant factor contributing to dental health.
In all likelihood, early humans had better dental health because of their diets. This affirms the author’s assumption that fewer health problems are a sign of better diets.
Summary
Each phase of a person’s life had predictable social roles in preagricultural societies. Social roles were few in these societies. Interpersonal relations in preagricultural societies were not always fair, but they were stable and predictable. Modern society has thousands of different roles. Technology and consumerism require people to fill several different roles that are differentiating at a high pace.
Strongly Supported Conclusions
Modern social roles are less stable and predictable than preagricultural social roles.
A
modern society is characterized by greater injustice and unpleasantness than were preagricultural societies
This is unsupported because modern roles may very well be more fair and pleasant than the preagricultural roles, which were not always fair and pleasant despite being stable and predictable.
B
interpersonal relations in modern societies are less stable and less predictable than they were in preagricultural societies
This is strongly supported because the stability and predictability of preagricultural roles was due to the relatively low number of roles. With the diversifying roles of modern society, these roles will likely be less stable and predictable.
C
the most important difference between modern and preagricultural societies is the variety and type of social roles permitted in each
This is unsupported because we don’t know how to rank the importance of the various differences between modern and preagricultural societies.
D
in modern societies, people must rely on technology to effectively predict and interpret other people’s actions
This is unsupported because the author states nothing about how one person can interpret or predict the actions of another.
E
preagricultural societies lacked the complex social system that is needed to provide each person with an appropriate and stable social role or niche
This is anti-supported because the stimulus states that preagricultural societies had stable social roles.
Summarize Argument
This argument concludes that governmental power over information must be reduced. The journalist supports this by saying that, in most countries, the government controls over half of the information that the public receives. This governmental control restricts the free marketplace of ideas. The free marketplace of ideas is what allows all ideas to receive fair consideration, so limiting this free marketplace can limit beneficial outcomes that come from free exchange of ideas. Further, the journalist claims that everyone concedes that governments should not suppress free expression, yet governments hold near monopolies on information.
Identify Conclusion
The conclusion is that the government should be restricted in its control over information: “The power of governments over information needs to be curtailed.”
A
The freedom of the marketplace of ideas is in jeopardy.
This is not the main conclusion. The argument makes a claim about the freedom of the marketplace of ideas in order to support the overall conclusion, which is that governmental control over information should be reduced.
B
Preserving a free marketplace of ideas is important.
The importance of the free marketplace of ideas is an unstated idea that provides support for the overall conclusion, which is that governmental control over information should be reduced, so this is not the main conclusion
C
The control that governments have over information needs to be reduced.
This is the main conclusion. The rest of the argument supports this claim by demonstrating the value of the free marketplace of ideas, and by showing that governmental monopolization of information can restrict free expression.
D
Ideas that have malicious content or stem from questionable sources can be valuable.
The argument says that ideas with malicious content can prompt beneficial outcomes; the argument does not say if the ideas themselves are valuable. Further, the value in the outcomes of these ideas exists as support for the main conclusion.
E
Governments have near monopolies on the dissemination of many kinds of information.
This claim about governmental control of information acts as a premise to demonstrate that governments are acting in a way that may impede the free expression of information. Further, we only know that governments “continue to construct” near monopolies, not that they have them.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that South America and Africa were once joined. This is because the continents used to be part of a single massive landmass, which then broke apart as plates shifted.
Notable Assumptions
The author assumes that South America and Africa are situated in such a way that suggests they were once joined before breaking apart.
A
A large band of ancient rock of a rare type along the east coast of South America is of the same type as a band on the west coast of Africa.
This is evidence that South America and Africa were once joined. The rare rock in question is unlikely to exist on both coasts if the continents weren’t joined at one point.
B
Many people today living in Brazil are genetically quite similar to many western Africans.
Continental drift happened long before humans existed. Such genetic differences have different explanations.
C
The climates of western Africa and of the east coast of South America resemble each other.
Irrelevant. Climates are affected by many things, but continental drift from millions of years ago aren’t one of them.
D
Some of the oldest tribes of people living in eastern South America speak languages linguistically similar to various languages spoken by certain western African peoples.
Like (B), continental drift happened long before humans. Such linguistic differences have different explanations.
E
Several species of plants found in western Africa closely resemble plants growing in South America.
Plants migrate for many reasons. It’s likely these species were carried across the ocean in more recent times.
Summarize Argument: Counter-Position
The author concludes that the public generally does not find violent movies offensive, contrary to the claims of legislators. As support, he cites a survey of frequent moviegoers in which the majority of respondents did not find violent movies offensive.
Identify and Describe Flaw
The author draws a conclusion about public opinion based on an industry survey of frequent moviegoers. This is the cookie-cutter flaw of relying on an unrepresentative sample: he fails to consider that the views of frequent moviegoers might not be representative of the public as a whole.
A
attempts to undermine the legislators’ credibility instead of addressing their argument
The author does address their argument: the problem is that his rebuttal is flawed, not that he didn’t make a rebuttal.
B
bases its conclusion on subjective judgments rather than on an objective criterion of moral offensiveness
The relevant criterion is subjective judgments (what the public thinks of violent movies), so this can’t be the flaw.
C
fails to consider the possibility that violent movies increase the prevalence of antisocial behavior
The argument in the stimulus is about what fraction of the public disapproves of violent movies. The actual consequences of the movies are irrelevant; what matters is what the public thinks.
D
generalizes from a sample that is unlikely to be representative of public sentiment
This is the cookie-cutter flaw of relying on an unrepresentative sample. The author commits this by citing a survey of frequent moviegoers as definitive evidence. They might differ from the public as a whole. So they can’t be used to draw a conclusion about the public in general.
E
presumes, without providing justification, that the people surveyed based their responses on a random sampling of movies
Whether the respondents had a random sample of movies is irrelevant: the argument is about what people in general think of violent movies. It doesn’t matter if their choice of movies is non-random. The problem is that the respondents themselves aren’t randomly sampled.