Summarize Argument
The author argues that rational-choice theory is not correct. She supports this by saying that if it were correct, then people would only act in ways that they expect will benefit them, but there are many examples of people acting in ways that do not benefit them.
Identify and Describe Flaw
By showing that many people act in ways that don’t benefit them, the author assumes that she’s negating the necessary condition for rational-choice theory being correct. But in reality, the necessary condition is that people will always act in ways that they expect will benefit them.
It’s possible that people expected to benefit from their actions, even though they didn’t benefit. In this case, the author can’t conclude that rational-choice theory is incorrect.
A
assumes as a premise the contention the argument purports to establish
This is the cookie-cutter flaw of circular reasoning, where the argument’s conclusion simply restates one of its premises. The author doesn’t make this mistake; her premises may not support her conclusion well, but they are distinct from her conclusion.
B
concludes that a theory is false merely on the grounds that the evidence for it is hypothetical
The author does conclude that rational-choice theory is false, but not on the grounds that the evidence for it is hypothetical. Instead, she concludes it’s false based on examples that she believes prove it to be false.
C
takes for granted that people who are acting in ways that are personally beneficial expected that their actions would be personally beneficial
Actually, the author assumes that people who are acting in ways that are not personally beneficial did not expect that their actions would be personally beneficial. (C) has this backwards.
D
presumes, without justification, that examples of people acting in ways that are not personally beneficial greatly outnumber examples of people acting in ways that are personally beneficial
The author never assumes there are more examples of people acting in ways that are not personally beneficial than people acting in ways that are. She just says there are “plenty” of examples of people acting in ways that don’t benefit them, which she thinks disproves the theory.
E
fails to consider that people acting in ways that result in no personal benefit may nonetheless have expected that acting in those ways would produce personal benefit
Just because people sometimes act in ways that don’t benefit them doesn’t mean that those people weren’t expecting to benefit from their actions. If they were, the author can’t conclude that rational-choice theory is incorrect.
Lopez: The real problem is mysis shrimp, which were originally introduced into the lake as food for mature kokanee; but mysis eat plankton—young kokanees’ food. The young kokanee are starving to death. So eradicating the shrimp is preferable to allowing trout fishing.
Summarize Argument
Lopez concludes eliminating non-native mysis shrimp would be better for the kokanee salmon population than allowing fishing for native trout. Why? Because while trout eat mature kokanee, mysis shrimp eat plankton, which lowers plankton levels enough that young kokanee salmon starve.
Notable Assumptions
Lopez assumes eliminating mysis shrimp and thus allowing more young kokanee to avoid starvation would be better for the kokanee population than fishing for native trout and thus allowing more adult kokanee to survive predation. This means assuming that removing the mysis shrimp would leave much more plankton available for young kokanee to eat.
A
Eliminating a non-native species from a habitat in which it threatens a native species is preferable to any other method of protecting the threatened native species.
This strong principle supports Lopez’s argument. Since the mysis shrimp is non-native and threatens the native kokanee population, it implies removing the shrimp is the best way to protect the kokanee.
B
When trying to protect the food supply of a particular species, it is best to encourage the method that will have the quickest results, all else being equal.
Without more information, this doesn’t strengthen or weaken Lopez’s argument. It’s not suggested that allowing trout fishing would protect the kokanee’s food supply, nor is it indicated which would work faster—removing the shrimp or removing the trout.
C
The number of species in a given habitat should not be reduced if at all possible.
This weakens Lopez’s argument. It implies other ways of helping the kokanee population—allowing trout fishing, for example—are preferable to removing a whole species, which Lopez advocates.
D
No non-native species should be introduced into a habitat unless all the potential effects of that introduction have been considered.
This supports not introducing mysis shrimp in the first place, but it says nothing about removing species that are already present. Since the mysis shrimp have already been introduced, this principle doesn’t apply.
E
When seeking to increase the population of a given species, it is most important that one preserve the members of the species who are in the prime reproductive stage of their lives.
If anything, this weakens Lopez’s argument. It implies mature kokanee should be prioritized, suggesting it would be better to allow trout fishing than to remove mysis shrimp.
Summary
People with low self-esteem are treated disrespectfully more often than people with high self-esteem. A recent experiment discovered when people with low self-esteem and people with high self-esteem receive the same treatment from others, people with low self-esteem are more likely to feel they have been treated disrespectfully.
Strongly Supported Conclusions
Thus, people with low self-esteem believe they are being treated disrespectfully more often than people with high self-esteem.
A
people with low self-esteem are usually right when they think they have been treated disrespectfully
This answer is unsupported. We don’t know from the stimulus whether the perceptions of people with low self-esteem are objectively correct or not. We only know people with low self-esteem believe that they are treated disrespectfully more often.
B
being treated disrespectfully tends to cause a person to develop lower self-esteem
This answer is unsupported. We don’t know from the stimulus what causes a person to develop low self-esteem. We only know that there is a correlation between low self-esteem and feeling disrespected.
C
if an individual has been treated disrespectfully, it is probably because the individual was perceived to have low self-esteem
This answer is unsupported. We don’t know from the stimulus what causes a person to be treated disrespectfully. We only know that there is a correlation between low self-esteem and feeling disrespected.
D
people with low self-esteem more frequently think that they are being treated disrespectfully than do people with high self-esteem
This answer is strongly supported. We know from the stimulus that even in the case where people with low self-esteem and people with high self-esteem receive the same treatment, the people with low self-esteem are more likely to feel disrespected.
E
a person with low self-esteem will be more inclined to treat others disrespectfully than will a person with high self-esteem
This answer is unsupported. We don’t know from the stimulus how people with low self-esteem treat others.
Summary
The author concludes that it would not be wrong to perform mining operations on Mars. Why? Because of the following:
These are the only 2 reasons it could be wrong to engage in an activity that causes pollution: (1) the pollution harms ecosystems, OR (2) pollution harms human populations.
Mining operations on Mars would pollute, but would not harm human populations.
These are the only 2 reasons it could be wrong to engage in an activity that causes pollution: (1) the pollution harms ecosystems, OR (2) pollution harms human populations.
Mining operations on Mars would pollute, but would not harm human populations.
Missing Connection
In order to be wrong, the mining operations must either harm ecosystems or harm human populations. We know that the operations won’t harm humans. But the premises don’t establish that the operations won’t harm ecosystems. So if we want to conclude that the operations would not be wrong, we want to know that they won’t harm ecosystems.
A
Mining creates less pollution than many other human activities.
(A) doesn’t establish that the mining operations on Mars won’t harm ecosystems.
B
There are no ecosystems on Mars.
(B) establishes that the mining operations won’t harm ecosystems. After all, if there are no ecosystem on Mars, then the mining operations there have no ecosystems to harm.
C
The economic benefits of mining on Mars would outweigh its costs.
(C) doesn’t establish that the mining operations on Mars won’t harm ecosystems.
D
It is technologically feasible to perform mining operations on Mars.
(D) doesn’t establish that the mining operations on Mars won’t harm ecosystems.
E
The more complex an ecosystem is, the more valuable it is.
(E) doesn’t establish that the mining operations on Mars won’t harm ecosystems.