Azadeh: The recent increase in the amount of organically produced food indicates that consumers are taking a greater interest in the environment. Thus, there is new hope for a healthier planet.

Ben: No, Azadeh, if you interviewed people who buy organic produce, you’d see that they’re actually as selfish as everyone else, since they’re motivated only by worries about their own health.

Speaker 1 Summary
Azadeh claims that the recent increase in organically produced food indicates that consumers are becoming more interested in the environment, leading to new hope for a healthier planet.

Speaker 2 Summary
Ben disagrees, stating that people who buy organic produce are motivated by selfish concerns for their health rather than environmental concerns.

Objective
Disagree: Aazadeh and Ben disagree over whether the increase in organically produced foods is an indicator that consumers are more interested in the environment.

A
it is likely that a healthy planet can be maintained if most people continue in their present eating habits
Neither speaker gives the conditions for how a healthy planet can be maintained. This is far too broad for any speaker to have an opinion on.
B
people can become healthier by increasing their consumption of organic foods
Azadeh does not have any position on this, and neither does Ben. Ben only talks about people who *believe* that it makes them healthier.
C
people ought to be more concerned about the environment than they currently are
Perhaps Azadeh supports this, but Ben does not give any position on how many people should be concerned about the environment.
D
the rise in organic food production shows people to have a greater concern for the environment than they had before
Azadeh directly supports this in his argument and Ben directly counters it but suggesting that people are more concerned with their own health
E
people can be persuaded to have a greater concern for the environment than they now have
Azadeh probably supports this, but Ben does not discuss whether people *can* be persuaded. He only mentions that the rise in organic food sales does not indicate that people are more concerned about the environment.

2 comments

Citizen: The primary factor determining a dog’s disposition is not its breed, but its home environment. A bad owner can undo generations of careful breeding. Legislation focusing on specific breeds of dogs would not address the effects of human behavior in raising and training animals. As a result, such breed-specific legislation could never effectively protect the public from vicious dogs. Moreover, in my view, the current laws are perfectly adequate.

Summarize Argument: Counter-Position
The citizen concludes that making laws that are breed-specific will not be effective in protecting against vicious dogs. This is because the primary cause of violence in dogs is environment, not breed. The citizen supports this causal claim by pointing out that a bad owner can override careful breeding. Because environment, not breed, is the primary determinant of disposition, breed-specific legislation will overlook the main cause of violence in dogs.

Identify Conclusion
The conclusion is that creating laws based on breed will not protect the public: “Breed-specific legislation could never effectively protect the public from vicious dogs.”

A
The public would not be effectively protected from violent dogs by breed-specific legislation.
This is the main conclusion. The rest of the argument supports this claim by showing that breed-specific legislation does not address the primary factor in determining disposition, which is home environment.
B
A good home environment is more important than breeding to a dog’s disposition.
This is a premise that supports the conclusion that breed-specific legislation will not be effective.
C
The home environment of dogs would not be regulated by breed-specific legislation.
This is a premise that shows why breed-specific legislation will not be effective: because it will not address the true primary cause of behavior.
D
Irresponsible dog owners are capable of producing dogs with bad dispositions regardless of generations of careful breeding.
This is a premise that demonstrates why home environment is more important than breed in determining the disposition of a dog.
E
The vicious-dog laws that are currently in effect do not address the effects of human behavior in raising and training dogs.
The only thing we know about the current laws is that the citizen thinks that they are perfectly accurate. We do not know what they do or do not address, so this cannot be the main conclusion.

4 comments

Legislator: To keep our food safe, we must prohibit the use of any food additives that have been found to cause cancer.

Commentator: An absolute prohibition is excessive. Today’s tests can detect a single molecule of potentially cancer-causing substances, but we know that consuming significantly larger amounts of such a chemical does not increase one’s risk of getting cancer. Thus, we should instead set a maximum acceptable level for each problematic chemical, somewhat below the level at which the substance has been shown to lead to cancer but above zero.

Summarize Argument

The commentator concludes that there should be a maximum acceptable level for potentially cancer-causing substances in food that is above zero but below the amount shown to cause cancer. This is because an absolute prohibition, as proposed by the legislator, is excessive, as one can consume some amount of these substances without increasing their risk of cancer.

Notable Assumptions

The commentator assumes that while it may be safe to consume some amount of these substances in one food without increasing one’s risk of cancer, this risk does not increase significantly if one consumes this same amount in various foods. In the same vein, the commentator assumes that ingesting a safe amount of one problematic chemical in addition to safe amounts of other problematic chemicals does not significantly increase one’s cancer risk.

A
The level at which a given food additive has been shown to lead to cancer in children is generally about half the level at which it leads to cancer in adults.

This does not affect the commentator’s argument. There is no reason to believe that the commentator’s suggested maximum acceptable levels for each substance do not account for children’s tolerance as well as that of adults.

B
Consuming small amounts of several different cancer-causing chemicals can lead to cancer even if consuming such an amount of any one cancer-causing chemical would not.

This weakens the commentator’s argument. It exploits the commentator’s assumption that the risk of cancer does not substantially increase when a safe amount of one problematic chemical is consumed in addition to a safe amount of another problematic chemical.

C
The law would prohibit only the deliberate addition of cancer-causing chemicals and would not require the removal of naturally occurring cancer-causing substances.

This does not affect the commentator’s argument, which discusses how chemicals should be regulated, not which chemicals should be regulated. If only some chemicals are covered, the commentator would just argue that acceptable limits should be set instead of complete prohibitions.

D
For some food additives, the level at which the substance has been shown to lead to cancer is lower than the level at which the additive provides any benefit.

This does not affect the commentator’s argument. The commentator does not compare the risk of cancer posed by additives to the potential benefit one derives from consuming them.

E
All food additives have substitutes that can be used in their place.

This does not affect the commentator’s argument. The existence of alternatives for the additives does not offer insight into how well the commentator’s proposed approach would work for either the additives or the alternatives, especially in contrast to the legislator’s approach.


6 comments

Consumer advocate: There is ample evidence that the model of car one drives greatly affects the chances that one’s car will be stolen. The model of car stolen most often in our country last year, for example, was also the model stolen most often in the preceding year.

Summarize Argument: Phenomenon-Hypothesis
The advocate concludes that some models of cars are more likely to be stolen than others. Why? Because the model of car that was stolen most often one year ago is the same as that stolen most often two years ago.

Identify and Describe Flaw
This is the cookie-cutter flaw of confusing percentages and amounts. The advocate draws an implied conclusion about how likely a certain kind of car is to be stolen (i.e. the percentage of said cars that are stolen). But his only support is the total number of thefts of that car model.
Without knowing how common this car model is, we have no way of knowing how likely it is to be stolen. What if this is simply the most popular model of car? In that case, even if it was stolen at the same rate as other models, the total number of stolen cars of this model would be higher.

A
fails to address adequately the possibility that the model of car that was stolen most often last year was the most common model of car in the consumer advocate’s country
If this is true, the fact that it was stolen the most doesn’t tell us that thieves targeted it more often than any other model of car. This undermines the advocate’s conclusion.
B
fails to address adequately the possibility that the age of a car also greatly affects its chances of being stolen
Whether age also affects the chances of being stolen is irrelevant; the author could agree that age matters, but stick to his conclusion that model also matters.
C
fails to address adequately the possibility that the car model that was stolen most often last year was stolen as often as it was because it has a very high resale value
This would support the author’s conclusion—it provides a potential reason why this model would be more likely to be stolen—so it can’t be the flaw.
D
presumes, without providing justification, that someone considering whether or not to steal a particular car considers only what model the car is
The advocate doesn’t presume that the model is the only reason a car might be likely to be stolen—merely that it’s one reason.
E
presumes, without providing justification, that the likelihood of a car’s being stolen should override other considerations in deciding which car one should drive
The advocate doesn’t presume anything about which car one should drive, so this can’t be the flaw.

11 comments

Laird: Pure research provides us with new technologies that contribute to saving lives. Even more worthwhile than this, however, is its role in expanding our knowledge and providing new, unexplored ideas.

Kim: Your priorities are mistaken. Saving lives is what counts most of all. Without pure research, medicine would not be as advanced as it is.

Speaker 1 Summary

Laird doesn’t make an argument, instead just stating the claim that pure research provides more value through expanding our knowledge than it does by helping to save lives.

Speaker 2 Summary

Kim’s argument supports the unstated conclusion that the most important contribution of pure research is in fact its medical applications. This is supported by the principle that saving lives is the most important goal, and the statement that pure research has helped to improve medicine (thereby presumably saving lives).

Objective

We’re looking for a point of disagreement. Laird and Kim disagree about whether medical advancements are the most valuable result of pure research.

A
derives its significance in part from its providing new technologies

Both speakers agree with this. Laird acknowledges that new technologies are an important result of pure research, just not the most important result. Kim places even more importance on the development of medical technology.

B
expands the boundaries of our knowledge of medicine

Both speakers almost certainly agree with this. Both Laird and Kim discuss the role of pure research in advancing medicine, which strongly implies that pure research has improved our knowledge of medicine.

C
should have the saving of human lives as an important goal

Kim agrees with this, but Laird never disagrees. Laird explicitly acknowledges the importance of pure research helping to save lives—the issue is just whether that’s the most important goal.

D
has its most valuable achievements in medical applications

Laird disagrees with this but Kim agrees, so this is the point at issue. Laird thinks that the most valuable achievements of pure research are in expanding our knowledge and providing new ideas, whereas Kim states that saving lives through medical advancement is more important.

E
has any value apart from its role in providing new technologies to save lives

Laird agrees with this, but Kim never disagrees. Kim’s argument is just that saving lives is the most important result of pure research, not that pure research has no other value.


13 comments

There have been no new cases of naturally occurring polio in North America in recent years. Yet there are approximately 12 new cases of polio each year in North America, all caused by the commonly administered live oral polio vaccine (OPV). Substituting inactivated polio vaccine (IPV) for most childhood polio immunizations would cut the number of cases of vaccination-caused polio about in half. Clearly it is time to switch from OPV to IPV as the most commonly used polio vaccine for North American children.

Summarize Argument
IPV should be the most commonly used polio vaccine for North American children, instead of OPV. OPV causes all new cases of polio each year in North America, and IPV would reduce the number of cases by half.

Notable Assumptions
The author assumes that IPV does not have serious side effects that make it undesirable for use on most children—side effects that may outweigh the benefit of decreasing the number of cases of live polio a year. Furthermore, the author assumes that there are no other significant undesirable consequences that could arise from the proposed switch.

A
If IPV replaces OPV as the most commonly used polio vaccine, at least a few new cases of naturally occurring polio in North America will result each year.
This weakens the argument. It exploits the author’s assumption that there are no significant undesirable consequences that could arise from the switch. (A) says if IPV replaces OPV, naturally occurring polio would result—something which has not occurred in recent years.
B
The vast majority of cases of polio caused by OPV have occurred in children with preexisting but unsuspected immunodeficiency disorders.
This does not affect the argument. The author advocates for a switch to IPV to reduce the annual number of polio cases. The specific characteristics of these cases—such as whether the affected children had undiagnosed immunodeficiency disorders—do not weaken the argument.
C
A child’s risk of contracting polio from OPV has been estimated at 1 in 8.7 million, which is significantly less than the risk of being struck by lightning.
This does not affect the argument. The author does not dispute the idea that the risk is slight; rather, the author argues that the risk could be further reduced by switching to IPV.
D
Although IPV is preferred in some European nations, most countries with comprehensive child immunization programs use OPV.
This does not affect the argument. The author’s argument is supported solely by evidence from North America, and the conclusion is specific to North America as well. What other continents or countries are doing is not relevant.
E
IPV, like most vaccines, carries a slight risk of inducing seizures in children with neurological diseases such as epilepsy.
This does not affect the argument. Both OPV and IPV are vaccines—this would apply to both equally.

39 comments

Columnist: Neuroscientists have found that states of profound creativity are accompanied by an increase of theta brain waves, which occur in many regions of the brain, including the hippocampus. They also found that listening to music increases theta waves dramatically. Thus, one can attain a state of profound creativity merely by listening to a tape of recorded music.

Summarize Argument: Phenomenon-Hypothesis
The author concludes that listening to music can trigger a state of profound creativity. This is because listening to music increases theta brainwaves. And increased theta brainwaves are found when someone is in a state of profound creativity.

Identify and Describe Flaw
This is the cookie-cutter flaw of assuming that correlation proves causation. The columnist observes that increased theta brainwaves are correlated with states of profound creativity. He then implicitly concludes that theta brainwaves cause a state of profound creativity. (And therefore music, by increasing theta brainwaves, can causally trigger that state.)
But this overlooks the possibility that it’s the other way around: maybe being in a state of creativity is what leads to higher theta brainwaves. Or maybe a third factor—say, waking up early in the morning—both triggers a state of profound creativity and increases theta brainwaves. If either of these were true, listening to music could increase theta brainwaves without triggering a state of profound creativity.

A
takes for granted that there is a causal connection between the hippocampus and being in a state of profound creativity
The proposed causal connection is about theta brainwaves, not any particular part of the brain. The theta brainwaves occur in “many regions of the brain” aside from the hippocampus.
B
fails to consider that music is not necessary for one to be in a state of profound creativity
The columnist doesn’t assume this, so it can’t be the flaw. The columnist is saying that music is sufficient (if you have it, you’ll get a profound creative state), not that it’s necessary (you can’t have the state without music).
C
does not rule out the possibility that listening to music by means other than a tape recording also increases theta waves
Even if this were true, it wouldn’t be a flaw in the argument. It’s perfectly possible for the columnist to also believe that listening to music in different formats also increases theta waves.
D
ignores the possibility that an increase in theta waves may not always be accompanied by a state of profound creativity
The author assumes that the correlation between theta waves and states of profound creativity means that theta waves cause states of profound creativity. But
E
provides insufficient reasons to believe that people who are not in states of profound creativity have low levels of theta brain waves
The columnist's conclusion only concerns people who are in states of profound creativity. Also, the columnist's language is relative—increased brainwaves accompany states of profound creativity. So the alternative could be moderate, rather than low, levels of brainwaves.

30 comments

In the troposphere, the lowest level of the earth’s atmosphere, the temperature decreases as one progresses straight upward. At the top, the air temperature ranges from –50 degrees Celsius over the poles to –85 degrees Celsius over the equator. At that point the stratosphere begins, and the temperature stops decreasing and instead increases as one progresses straight upward through the stratosphere. The stratosphere is warmed by ozone. When an ozone particle absorbs a dose of ultraviolet sunlight, heat is generated.

Summary
The stimulus discusses two layers of the atmosphere: the troposphere (the lowest level) and the stratosphere (the layer above the troposphere).
In the troposphere, it gets colder as you go straight up.
At the top of the troposphere, the temperature ranges from -50 degrees Celsius (over the poles) to -85 degrees Celsius (over the equator).
Once the stratosphere begins, temperature beings to increase as you go straight up.
In the stratosphere, heat is generated when an ozone particle absorbs ultraviolet sunlight.

Notable Valid Inferences
Any point in the troposphere is colder than any other point in the troposphere directly below it.
Any point in the stratosphere is warmer than any other point in the stratosphere directly below it.
A point in the stratosphere is equal temperature or warmer than the highest point in the troposphere directly below it.

A
The troposphere over the poles is thicker than the troposphere over the equator.
This could be false. We don’t know anything about the thickness of any layers of the atmosphere.
B
It is warmer at the top of the stratosphere over the poles than it is at the top of the stratosphere over the equator.
This could be false. We don’t know anything about the rate of temperature increase in the stratosphere; it could be the case that the temperature over the equator increases more quickly than the temperature above the poles.
C
The temperature in the middle part of the stratosphere over the North Pole is at least as great as the temperature in the middle part of the stratosphere over the equator.
This could be false. We only know the temperature at the point where the troposphere ends and the stratosphere begins; we don’t have enough information to compare points in the middle of the stratosphere.
D
The temperature at any point at the top of the stratosphere is at least as great as the temperature at the top of the troposphere directly beneath that point.
This must be true. We know that, in the stratosphere, the temperature increases as you go straight up. Because of this, we can infer that any point in the stratosphere is at least as high as the point below it, going all the way down to the highest point of the troposphere.
E
Depletion of the earth’s ozone layer would increase the air temperature in the stratosphere and decrease the air temperature in the troposphere.
This could be false. All we know about ozone is that it plays a role in warming the stratosphere; we have no reason to believe that removing something that generates warmth would cause the stratosphere to become warmer.

22 comments

Essayist: Many people are hypocritical in that they often pretend to be more morally upright than they really are. When hypocrisy is exposed, hypocrites are embarrassed by their moral lapse, which motivates them and others to try to become better people. On the other hand, when hypocrisy persists without exposure, the belief that most people are good is fostered, which motivates most people to try to be good.

Summary

An essayist details what happens when hypocrisy is and is not exposed. When hypocrisy is exposed, hypocrites become embarrassed and try to become better people. When hypocrisy remains unexposed, people believe that most people are good, which motivates most people to be good.

Strongly Supported Conclusions

Whether or not hypocrisy is exposed, some people will try to better themselves.

A
The existence of hypocrisy encourages people to believe that no one is morally blameless.

This is too strong to support. The stimulus only says that embarrassed hypocrites try to better themselves once hypocrisy is exposed.

B
The existence of hypocrisy encourages people to make efforts to live by moral standards.

The stimulus details that some people will strive to become more morally virtuous whether hypocrisy is exposed or not. Thus, this is easily supported

C
The existence of hypocrisy in some people encourages others to fall into moral lapses.

The stimulus does not say anything about when people fall into moral lapses.

D
The hiding of hypocrisy is a better way of motivating people to try to be good than is the exposing of it.

This comparative statement does not receive enough support. The stimulus does not say one approach is better than the other.

E
There is no stronger motivator for people to try to be good than the exposing of hypocrisy.

This is too strong to support. The stimulus says that exposing hypocrisy is *a* motivator, not that it is the strongest one.


13 comments