Brain-scanning technology provides information about processes occurring in the brain. For this information to help researchers understand how the brain enables us to think, however, researchers must be able to rely on the accuracy of the verbal reports given by subjects while their brains are being scanned. Otherwise brain-scan data gathered at a given moment might not contain information about what the subject reports thinking about at that moment, but instead about some different set of thoughts.

Summarize Argument
The author makes a claim about what needs to occur in certain studies. Using brain scanning technology to understand thinking requires accurate verbal reports from the subjects being scanned. This is because the brain scan data would not contain useful information about thought processes if the subject reports thinking one thing, but is actually thinking another.

Identify Conclusion
The conclusion is what needs to occur: “For this information to help researchers understand how the brain enables us to think, researchers must be able to rely on the accuracy of the verbal reports given by subjects while their brains are being scanned.”

A
It is unlikely that brain-scanning technology will ever enable researchers to understand how the brain enables us to think.
This concept is not contained in the stimulus. The stimulus concludes what needs to happen, not what is likely or unlikely.
B
There is no way that researchers can know for certain that subjects whose brains are being scanned are accurately reporting what they are thinking.
This concept is not contained in the stimulus. We know we need accurate information, but there is no discussion of certainty.
C
Because subjects whose brains are being scanned may not accurately report what they are thinking, the results of brain-scanning research should be regarded with great skepticism.
This concept is not contained in the stimulus. The stimulus concludes what needs to happen for data to be accurate, not how the results should be regarded.
D
Brain scans can provide information about the accuracy of the verbal reports of subjects whose brains are being scanned.
This is not contained in the stimulus. We know that the reports need to be accurate, but there is no information about the scans evaluating accuracy.
E
Information from brain scans can help researchers understand how the brain enables us to think only if the verbal reports of those whose brains are being scanned are accurate.
This accurately restates the argument the author is making - what needs to happen in order for the research to serve its purpose.

2 comments

Ornithologist: This bird species is widely thought to subsist primarily on vegetation, but my research shows that this belief is erroneous. While concealed in a well-camouflaged blind, I have observed hundreds of these birds every morning over a period of months, and I estimate that over half of what they ate consisted of insects and other animal food sources.

A
assumes, without providing justification, that the feeding behavior of the birds observed was not affected by the ornithologist’s act of observation
The author notes that she was concealed behind a “well-camouflaged blind” — so there is some justification for the assumption that the feeding wasn’t affected. In any case, the author just needs to assume that the birds didn’t change the vegetation/non-veg. makeup of their diet.
B
fails to specify the nature of the animal food sources, other than insects, that were consumed by the birds
The point of the observation is that the birds ate mainly non-vegetation in the morning. The particular kinds of food don’t matter as long as they’re not vegetation.
C
adopts a widespread belief about the birds’ feeding habits without considering the evidence that led to the belief
The author rejects the widespread belief that that the bird eats primarily vegetation.
D
neglects the possibility that the birds have different patterns of food consumption during different parts of the day and night
If the birds might have different patterns of food consumption at other times of day, that opens the possibility that the bird could eat primarly vegetation at other times of day. So the author’s observations of the birds’ diet might not be representative of the overall diet.
E
fails to consider the possibility that the birds’ diet has changed since the earlier belief about their diet was formed
If the birds’ diet has changed since the earlier belief was formed, that doesn’t undermine the author’s reasoning. The author is simply trying to prove that the bird doesn’t eat primarily vegetation.

The question stem reads: The reasoning in the ornithologist's argument is most vulnerable to criticism on the grounds that the argument… This is a Flaw question.

The ornithologist begins by stating how a particular bird species (we will call this bird "X") diet is believed to consist primarily of vegetation (plants). However, the ornithologist concludes that belief is wrong. In other words, The ornithologist argues that "X" birds' diets are mostly not plants. As evidence, he describes how he camouflaged himself and watched hundreds of "X" birds every morning for a month. During his morning observations, he estimates that over half of what "X" birds ate were insects and animal food resources (not plants). This line of reasoning is flawed because the ornithologist only observed birds during the morning. Let's say I hypothesized that the belief humans frequently drink coffee is wrong. To prove my theory, I hid in people's closets for many months and watched their bedtime routines. During my observations, I noticed very few people drank coffee. Hypothesis proven, right? No! The problem is that I only observed people at night when they were unlikely to drink coffee. The other problem is that I shouldn't hide in people's closets. An ideal experiment has a representative sample.

Similarly, the ornithologist has only observed what "X" birds eat in the morning. However, what "X" birds eat in the morning might be unrepresentative of their diet on the whole. Now that we have identified our flaw let's move to the answer choices.

Answer Choice (A) is wrong. The ornithologist says he camouflaged himself. You might argue that perhaps his camouflage was ineffective. However, our job LSAT flaw questions in the reasoning, not to question the truth of the premises. Even if he did camouflage himself well, his argument is still problematic (he was only watching "X" birds in the morning!).

Answer Choice (B) is wrong. The ornithologist does not need to describe exactly what kinds of food "X" birds ate. He needs to say that plants accounted for 50% or less of their diet. So if it was true that most of "X" birds' diets were insect and animal food sources, that would imply 50% or less of "X" birds' diet was plants.

Answer Choice (C) is wrong. The author does not adopt the widespread belief. The author rejects the widespread idea that "X" birds' diet is mostly plants.

Correct Answer Choice (D) is what we discussed. If it was confirmed that "X" birds have different feeding patterns throughout the day, the ornithologist made an error by taking an unrepresentative sample of the birds' diet.

Answer Choice (E) is incorrect. Mapping on the stimulus to (E), we would get: fails to consider the possibility that "X" birds diet has changed since the earlier belief that "X" birds mostly ate plants was formed. Even if it was true that the popular belief was formed when "X" birds used to mostly eat plants, what matters is what the birds eat now. If "X" birds mostly eat insects and animals, then the popular belief is wrong. Being right in the past doesn't make you any less wrong in the present.


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Professor: A person who can select a beverage from among 50 varieties of cola is less free than one who has only these 5 choices: wine, coffee, apple juice, milk, and water. It is clear, then, that meaningful freedom cannot be measured simply by the number of alternatives available; the extent of the differences among the alternatives is also a relevant factor.

Summarize Argument
The professor concludes that freedom cannot only be measured by the number of options available to someone, and that the variety available in those options is also a relevant part of freedom. This is based on an example about beverages: someone with many beverage options all of a similar kind is less free than someone with fewer beverage options of more various kinds.

Describe Method of Reasoning
The professor draws a conclusion about a general principle using a specific example. The professor uses one hypothetical case where someone has multiple choices—in this case, of beverages—to show that freedom depends on not just the number of choices, but also on the meaningful differences between those choices.

A
supporting a general principle by means of an example
The professor supports the general principle that freedom depends not just on the number of available choices but also on the variety of those choices, by means of an example about a person choosing from a selection of beverages.
B
drawing a conclusion about a particular case on the basis of a general principle
The professor does not make claims about one case from a general principle, but the opposite: the professor draws a conclusion about general principle based on one example case.
C
supporting its conclusion by means of an analogy
The professor does not draw an analogy between cases to support a conclusion. Instead, only one case is used as an example to support the general principle which makes up the professor’s conclusion.
D
claiming that whatever holds for each member of a group must hold for the whole group
The professor does not make any claims about how qualities of group members relate to qualities of a whole group.
E
inferring one general principle from another, more general, principle
The professor does not infer a general principle from another general principle, but rather infers a general principle from a specific example case.

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The question stem reads: The reasoning in which of the following is most similar to that in the naturalist's argument? This is a Parallel question.

The naturalist begins by claiming that a species can survive the change in an environment as long as the change is not too rapid. The naturalist has provided a general rule saying that the change can be ok for a species, with the caveat that the change does not occur too rapidly. The naturalist concludes that the threats humans create to woodland species arise not from cutting down trees but from the rate at which we are cutting down trees. The naturalist has applied the universal rule about species to the specific example of woodland species. So the problem is not that change we are creating by cutting down trees, but the because we are causing the change too rapidly.

When evaluating an answer choice, we need a universal rule with a caveat. The correct AC will apply that universal rule to a specific example and say that the specific example is failing to satisfy the caveat.

Answer Choice (A) is incorrect. (A) does not provide a universal rule; it only gives a specific rule about fossil fuels. Additionally, (A) 's rule about fossil fuels lacks the caveat we are looking for.

Answer Choice (B) is incorrect. We can quickly eliminate (B) because of the word "many." Remember, we need a universal rule, so if (B) was right, it would begin with "all people." Additionally, (B) 's rule lacks the caveat we are looking for, nor does (B) apply its rule to a specific example.

Answer Choice (C) is incorrect. Similar to (B), we can eliminate (C) because it says "some" when we are looking for a universal rule. Additionally, (C) also lacks the caveat, nor does (C) apply the rule to a specific example.

Correct Answer Choice (D) matches the stimulus. (D) provides a general rule that "people do not fear change," under the caveat people know what the change will bring. (D) then applies that rule to the specific example of the author's company's employees. The company's employees' fears arise from the fact the company is changing, but because they do not know what the change will bring (the caveat is not satisfied).

Answer Choice (E) is incorrect. (E) does not provide a general rule, so we can eliminate it.


25 comments

A recent survey indicates that the average number of books read annually per capita has declined in each of the last three years. However, it also found that most bookstores reported increased profits during the same period.

"Surprising" Phenomenon
Why have most bookstores reported increased profits in the last three years even though a survey shows the average number of books read annually per person has declined in each of the last three years?

Objective
This is an EXCEPT question. The four wrong answers will tell us something has changed over the past three years that might lead to more bookstore profits despite a decline in average books read.

A
Recent cutbacks in government spending have forced public libraries to purchase fewer popular contemporary novels.
If libraries have fewer popular contemporary novels, more people might be going to bookstores to read those popular novels. This is how bookstore profits might have increased despite a general decline in books read.
B
Due to the installation of sophisticated new antitheft equipment, the recent increase in shoplifting that has hit most retail businesses has left bookstores largely unaffected.
This tells us bookstores haven’t been very affected by a recent spike in shoplifting. But we would still expect bookstore profits to be lower due to the general decline in reading. (B) isn’t giving us a reason to think bookstores could somehow increase their profits.
C
Over the past few years many bookstores have capitalized on the lucrative coffee industry by installing coffee bars.
Bookstores might be making more money from coffee bars today compared to the past. This could explain how bookstore profits could increase despite an overall decline in books read.
D
Bookstore owners reported a general shift away from the sale of inexpensive paperback novels and toward the sale of lucrative hardback books.
Bookstores might be selling more hardback books, which have higher profits margins (”more lucrative”). This could explain how bookstore profits might have increased despite a general decline in books read.
E
Citing a lack of free time, many survey respondents indicated that they had canceled magazine subscriptions in favor of purchasing individual issues at bookstores when time permits.
People might have increased purchases at bookstores in lieu of reading magazines delivered or emailed directly to them from a subscription. This could explain how bookstore profits might have increased despite a general decline in books read.

57 comments

People who object to the proposed hazardous waste storage site by appealing to extremely implausible scenarios in which the site fails to contain the waste safely are overlooking the significant risks associated with delays in moving the waste from its present unsafe location. If we wait to remove the waste until we find a site certain to contain it safely, the waste will remain in its current location for many years, since it is currently impossible to guarantee that any site can meet that criterion. Yet keeping the waste at the current location for that long clearly poses unacceptable risks.

Summary
There are people who argue against the proposed hazardous waste site based on implausible scenarios where the site fails. These people overlook the significant risks associated with delaying moving the waste from its currently unsafe location. If the waste is not moved until a safe site is found, the waste will remain in its current location for years. This is because it's impossible to guarantee that any proposed sight will meet the criteria for being labeled “safe.” Keeping the waste at the current unsafe location for that long presents unacceptable risks.

Strongly Supported Conclusions
The waste should be moved to a new site to reduce risks

A
The waste should never have been stored in its current location.
The stimulus does address past decisions. It is purely concerned with what future actions should be taken.
B
The waste should be placed in the most secure location that can ever be found.
This is antisupported. The stimulus argues against waiting for the most secure location because leaving the waste in the current location presents far too many risks.
C
Moving the waste to the proposed site would reduce the threat posed by the waste.
The stimulus acknowledges that moving the waste is risky, but that it would outweigh the risk of leaving it in its current location. Thus, moving the waste to the proposed site would decrease the overall risk.
D
Whenever waste must be moved, one should limit the amount of time allotted to locating alternative waste storage sites.
This is too broad to support. The stimulus is only concerned with this specific instance and there is no indication that this reasoning should be applicable to “whenever waste must be moved.”
E
Any site to which the waste could be moved will be safer than its present site.
This is too strong to support. The stimulus suggests that the *proposed* site would be safer, not any site whatsoever. What if the waste was dumped on a daycare?

25 comments

People perceive color by means of certain photopigments in the retina that are sensitive to certain wavelengths of light. People who are color-blind are unable to distinguish between red and green, for example, due to an absence of certain photopigments. What is difficult to explain, however, is that in a study of people who easily distinguish red from green, 10 to 20 percent failed to report distinctions between many shades of red that the majority of the subjects were able to distinguish.

"Surprising" Phenomenon
Why did 10 to 20 percent of people who could easily distinguish red from green fail to report a distinction between many shades of red that the majority of people who could distinguish red from green were able to distinguish?

Objective
The correct answer will be the only answer that doesn’t help explain the phenomenon where 10 to 20 percent of people who could easily distinguish red from green failed to report a distinction between many shades of red. The correct answer must give us information that doesn’t affect our understanding of the phenomenon or information that makes the phenomenon more difficult to explain.

A
People with abnormally low concentrations of the photopigments for perceiving red can perceive fewer shades of red than people with normal concentrations.
This could account for the non-colorblind people who were unable to distinguish between certain shades of red. They may have had an abnormally low concentration of the photopigments for perceiving red.
B
Questions that ask subjects to distinguish between different shades of the same color are difficult to phrase with complete clarity.
If these sorts of questions are difficult to phrase clearly, the non-colorblind people who failed to distinguish between certain shades of red may have actually been able to distinguish between the shades but just misunderstood the questions they were being asked.
C
Some people are uninterested in fine gradations of color and fail to notice or report differences they do not care about.
If (C) is true, the people who failed to distinguish between the various shades of red may have actually been able to distinguish between the shades but just didn’t care enough about the distinctions to notice them or report them.
D
Some people are unable to distinguish red from green due to an absence in the retina of the photopigment sensitive to green.
Reasons why some people can’t distinguish red from green are irrelevant. We need to know why 10 to 20 percent of the people who are capable of distinguishing red from green failed to distinguish between many shades of red.
E
Some people fail to report distinctions between certain shades of red because they lack the names for those shades.
If (E) is true, the people who failed to distinguish between the various shades of red may have actually been able to distinguish between the shades but just didn’t know the words necessary to report the distinctions.

7 comments

Doctor: In three separate studies, researchers compared children who had slept with night-lights in their rooms as infants to children who had not. In the first study, the children who had slept with night-lights proved more likely to be nearsighted, but the later studies found no correlation between night-lights and nearsightedness. However, the children in the first study were younger than those in the later studies. This suggests that if night-lights cause nearsightedness, the effect disappears with age.

Summarize Argument: Phenomenon-Hypothesis
The author concludes that, if night-lights cause nearsightedness, that effect disappears as one gets older. This is based on three studies. In the first study, researchers found a correlation between having slept with night-lights as a baby and having near-sightedness as a child. In the other two studies, which involved older children than those involved in the first study, reserachers found no correlation between night-lights and nearsightedness.

Notable Assumptions
The author assumes that the reason two studies found a lack of correlation between night-lights and nearsightedness is that any nearsightedness must have disappeared as children got older.
It’s important to note that the author is not assuming that night-lights actually cause nearsightedness. The author’s conclusion is just that if night-lights cause nearsightedness, then the effect disappears with age.

A
A fourth study comparing infants who were currently sleeping with night-lights to infants who were not did not find any correlation between night-lights and nearsightedness.
This study provides evidence that sleeping with night-lights doesn’t cause nearsightedness in infants. But the author never assumed that it did. The conclusion is just that *if* there’s a causal relationship, that effect disappears with age.
B
On average, young children who are already very nearsighted are no more likely to sleep with night-lights than young children who are not already nearsighted.
This helps eliminate the possibility that children who are already nearsighted might sleep with night-lights at a higher rate than those who aren’t nearsighted. But this doesn’t relate to disappearance with age.
C
In a study involving children who had not slept with night-lights as infants but had slept with night-lights when they were older, most of the children studied were not nearsighted.
This helps show that sleeping with night-lights as an older child does not cause nearsightedness. But these children didn’t sleep with night-lights as infants. So it doesn’t help examine whether effects disappear as a child gets older.
D
The two studies in which no correlation was found did not examine enough children to provide significant support for any conclusion regarding a causal relationship between night-lights and nearsightedness.
This weakens by reducing the reliability of the two studies. If they didn’t examine enough children to provide significant support for a conclusion about cause, then the author can’t rely on them to conclude that the effect of night-lights disappears with age.
E
In a fourth study involving 100 children who were older than those in any of the first three studies, several of the children who had slept with night-lights as infants were nearsighted.
That “several” of the children were nearsighted does not establish a correlation between nearsightedness and night-lights in the study. It’s possible the almost all who slept with night-lights didn’t have nearsightedness, even if several did.

111 comments