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MCAT · Critical Analysis and Reasoning Skills · Foundations of Comprehension

Main idea and purpose

Main idea and purpose is part of Foundations of Comprehension in the MCAT Critical Analysis and Reasoning Skills section. The questions below are written in the style of the real test, each with the answer and a worked explanation.

Question types you will see here include central thesis, author's primary purpose, overall organization and position among competing views.

Common traps: too narrow: promotes one paragraph's example or sub-claim to the main point; too extreme: drops the author's hedge and adds always/never/only; true-but-not-answering: an accurate detail from the passage that is not the overall point.

Sample questions

  1. Rituals Without Believers

    Anthropologists who study ritual in small-scale societies have sometimes been accused of a double standard. Among distant peoples, they find meaning in every procession and offering; at home, surrounded by retirement parties, graduation ceremonies, and the singing of birthday songs over a cake nobody especially wants, they tend to see only empty convention. The implicit assumption is that a ritual works by expressing belief, and that when participants no longer believe, or perform with an ironic shrug, the ritual has hollowed out.

    I think this assumption gets ritual backward. Much of what ritual accomplishes does not depend on what participants privately think at all.

    Consider the office retirement party. Few of the people eating sheet cake in a conference room believe that the event transforms the retiree in any metaphysical sense. Many attend reluctantly, and the speeches are often clichéd. Yet the party does something that an email announcement could not. It marks a change of status publicly, so that everyone present knows that everyone else knows the retiree is leaving. It gives colleagues a sanctioned occasion to express regard they would find awkward to express unprompted. And it closes a chapter in a way that allows the organization, and the retiree, to move on. None of these effects requires sincerity. They require only that people show up and go through the motions together.

    The phrase "going through the motions" is usually an insult, but in the case of ritual it is closer to a definition. What distinguishes ritual from other forms of communication is precisely that its meaning is carried by the form rather than by the inner states of those performing it. A wedding vow is binding not because the couple feels a particular emotion at the moment of speaking (they may be nervous, distracted, or overwhelmed) but because the words were said in the proper setting before witnesses. The form does the work so that the feelings do not have to.

    Critics may object that this makes ritual sound mechanical, and that surely a ceremony performed with conviction is better than one performed without it. I agree that conviction can enrich a ritual; a funeral at which mourners genuinely grieve is a different experience from one at which they are merely present. But enrichment is not the same as efficacy. The funeral accomplishes its social work, acknowledging a death, redistributing roles, gathering the community around the bereaved, whether or not every mourner is moved. If ritual required sincerity, it would be fragile in exactly the moments when it is most needed, since grief, fear, and exhaustion are hardly conditions in which people reliably summon the right emotions.

    This view has a practical implication. Institutions sometimes abandon rituals because participants seem to find them perfunctory, replacing them with nothing or with more "authentic" alternatives designed to elicit genuine feeling. The results are often disappointing. The authentic alternative, precisely because it asks for feeling, can make people self-conscious, and without a shared form there is no way to know when the thing has been done. A perfunctory ritual may be doing more than it appears to.

    None of this is to say that every convention deserves preservation. Some rituals encode hierarchies or exclusions that ought to be challenged. But the fact that participants do not believe in a ritual, or perform it half-heartedly, is not by itself evidence that it has stopped working.

    Question 1

    Which of the following best states the central claim of the passage?

    • A.

      The social effects of a ritual often depend on its public form rather than on the sincere belief of its participants.

    • B.

      Modern secular rituals are empty conventions that should be replaced.

    • C.

      Rituals in small-scale societies carry deeper meaning than the ceremonies of industrial societies, which have become empty conventions.

    • D.

      A ritual is effective only when its participants feel genuine emotion.

  2. Money Sent Home

    When a worker abroad sends part of a month's wages to relatives at home, the transfer is small, private, and, to the family receiving it, enormously consequential. When millions of workers do the same, the sums rival what some countries earn from their exports or receive in foreign aid, and it is natural to ask whether this flow can do for a nation what no single family can do for itself. Policymakers in several migrant-sending countries have answered yes and have designed programs to channel remittances toward investment. I want to argue that this hope asks the money to do something it was never sent to do.

    Begin with the motive for sending. The evidence of when money moves suggests that remittances respond to need. They tend to rise when a harvest fails, when a relative falls ill, or when a flood or a currency collapse strikes the village, and to ease when household fortunes recover. A flow that moves in step with the recipients' hardships is behaving like insurance: it is paid out when losses occur, and the migrant is in effect the family's underwriter. Insurance has great value. It lets households avoid selling a plough or withdrawing a child from school in a bad year. But it is not capital, and its value lies precisely in being spent when the emergency arrives.

    The second use is steadier consumption: food, rent, school fees, medicine. These are investments of a kind, since a better-fed child learns more, and I do not wish to belittle them. But they raise the well-being of households without necessarily raising the output of the economy. When people say that remittances "drive development," they usually mean something else: that the money is turned into businesses, machinery, and jobs for others. Where this happens, it tends to be in places that already offer decent roads, reliable credit, and a prospect of profit. There the migrant's money can finance a workshop; elsewhere the same money is sensibly spent on a roof.

    It may be objected that households would invest if only they were offered better instruments, such as bonds for migrants or matching grants for small businesses. Programs of this kind deserve a fair trial, and some have helped. Yet such designs have often met modest take-up, and the reason is not ignorance. A family that relies on remittances to cover its risks cannot lock the same money into a venture without exposing itself to the very hazards the remittances exist to cover. Its preference for ready cash is not a failure of imagination but a rational response to a world in which no one else will cover the loss.

    None of this implies that remittances are unimportant to a nation. By steadying household incomes they steady local demand, ease the pressure of poverty, and give families the security from which longer plans become thinkable. It would be a mistake to treat the insurance function as a lesser one. The mistake lies in a policy that counts on the flow for something else. A government that budgets as though remittances will finance growth, or that taxes them to pay for projects, risks undermining the very feature that makes them valuable: their responsiveness to the needs of families.

    The cautious implication is that policy should aim at making the money cheaper and safer to send before it aims at making it productive. Lower transfer fees, dependable channels, and protection against the sudden loss of a migrant's job are modest goals, but they strengthen the function remittances already serve. Whether a more ambitious role will emerge as roads, credit, and institutions improve remains an open question, and if it is answered at all, it will more likely be answered by those improvements than by anything done to the remittance itself.

    Question 2

    Which of the following is the view that the passage is chiefly written to counter?

    • A.

      Remittances act as a form of insurance for the households that receive them.

    • B.

      Remittances now exceed exports and foreign aid as a source of income for every migrant-sending country.

    • C.

      Governments ought to tax remittances in order to pay for public projects.

    • D.

      Remittances can serve as an engine of national development if they are properly channeled.

  3. Where the Line Falls

    Few questions in biology generate as much heat as the question of whether two populations are one species or two. Treatises have been written, and conferences have broken up, over groups of birds, orchids and beetles. The usual way to understand such quarrels is as disputes about evidence. Somewhere, the story goes, there is a fact of the matter, a single correct arrangement of living things that nature has already made, and disagreement persists because we have not yet gathered enough data to read it. I think this picture, though natural, is partly mistaken. Some disagreements about species are not failures of knowledge, because the thing being asked about is not wholly settled by nature.

    Consider a worked example. Two populations of a small flowering plant grow on opposite sides of a mountain ridge. They differ slightly in the shape of their petals and flower in different weeks; where their ranges overlap, in a narrow valley, they occasionally produce hybrids, which are fertile but poorly adapted. How many species are there? A geneticist who studies how gene flow is restricted may say one, since the hybrids are fertile and genes pass between the groups, however sparingly. A horticulturist who wants to know which plants will thrive in a given garden may say two, since in practice the groups behave differently and need different care. A conservation agency deciding whether the populations merit separate protection may also say two, for yet another reason: that to treat them as one might let the rarer one vanish unnoticed. All three have the same plants, the same measurements and the same facts about the hybrids. They are not disagreeing about the facts.

    The objection arrives at once: if the answer depends on what the classifier wants, then classification is arbitrary, and one may carve nature however one pleases. This does not follow. Purposes do not manufacture the differences; they select among differences that really exist. Petal shape and flowering time are real and measurable, as is the fertility of the hybrids. Nothing about the geneticist's interests can make the hybrids sterile, and nothing about the conservationist's can make the groups indistinguishable. What interests do is decide which of these real features should carry weight in drawing the line. A mapmaker serving sailors and one serving hikers draw different maps of the same coastline, and neither draws a mountain where there is a lake.

    I do not wish to say that all classifications are equally good. Some purposes are better served by some lines, and some lines serve no purpose at all. A scheme that grouped plants by the color of the pots they were sold in would damage every purpose that matters. Nor do I deny that accumulating evidence sometimes does settle a dispute; a population once thought distinct has occasionally turned out to be a variant of a familiar species. My claim is that evidence settles some questions and leaves others open, and that among those it leaves open there is no hidden correct answer waiting to be discovered, only a choice to be made for reasons that should be stated.

    To say so is not to cheapen the work of taxonomists. It is to ask them to say what each line is for, and to stop treating every dispute as a measure of someone's ignorance. A division of living things can be both useful and accurate, as a map can be both selective and true.

    Question 3

    Which of the following best states the central claim of the passage?

    • A.

      Species boundaries are arbitrary human conventions that no evidence can constrain, so that every classification is as good as any other.

    • B.

      Disagreements about where to draw species boundaries sometimes reflect differing human purposes and not merely gaps in knowledge about the organisms.

    • C.

      A geneticist, a horticulturist and a conservation agency would classify the same two plants differently, each for good reason.

    • D.

      There is a single correct classification of living things that taxonomists will eventually discover with enough data.

  4. Why the Ladder Holds

    Social theorists have long treated belief in merit as the ideology of the winners. The reasoning is simple and has the charm of cynicism. Those who rise need a story that turns luck, inheritance and connection into achievement, and the story of merit supplies one: I am here because I am better, not because of whom I knew. Those who fall short, it is assumed, can see through the story, since they stand where its failures are visible. If this is right, belief in merit should thin out as one descends the ladder, and the bottom rungs should be the home of skeptics.

    The evidence does not bear this out. In a survey of some 3,400 working adults in three cities, respondents were asked how far they agreed that people in their society get ahead mainly through talent and effort. Among those in the top income quartile, 78 percent agreed; among those in the bottom quartile, 71 percent did. A seven-point gap is real, but it is small beside the gap one would expect if the story were a luxury of the successful. More striking, respondents who had been made redundant in the preceding two years agreed at 74 percent, hardly below the 77 percent of those who had kept their jobs.

    Why would those at the bottom hold a belief that appears to condemn them? Three reasons suggest themselves. First, the belief offers hope: if talent and effort are what count, a child's prospects are not fixed by her parents' circumstances, and a poor parent has every reason to want that to be true. Second, the alternative is costly. To conclude that the contest is rigged is to conclude that effort is wasted, and few people can sustain daily labor on that footing. Third, merit supplies the common measure by which people judge themselves, so that a setback is read as a verdict on oneself and not on the arrangements. Inequality is rarely held in place by the grip of those at the top; it is held in place by the willingness of those at the bottom to keep climbing the same ladder.

    None of this means that the belief is unconditional. Respondents notice favoritism: 62 percent said they knew of a case in their own workplace where a post had gone to a relative or friend of someone senior. Yet among these respondents, 72 percent still agreed that people get ahead mainly through talent and effort, scarcely fewer than the 77 percent among those who knew of no such case. They treated the case they knew as an exception, an abuse of a rule that remained sound, and in doing so they left the rule intact. A principle that survives its counterexamples by classifying them as abuses is a sturdy one.

    A stabilizing effect plausibly follows. In the same survey, support for higher taxes on large incomes was lowest among the strongest endorsers of merit, and this held within each income quartile. People who hold themselves responsible for their position are less inclined to demand that the arrangements change, and where merit is believed by those who lose, the arrangement needs few enforcers. This does not make the winners' beliefs unimportant, and the belief does flatter them. My claim is narrower. Calling meritocratic belief an ideology of the winners is accurate about who benefits and mistaken about who holds it. The mistake has practical consequences. If the belief were a delusion confined to the comfortable, exposing a few rigged appointments might be enough to dissolve it. Because it is held for reasons of its own by those at the bottom, such exposure will mostly be absorbed as one more exception.

    Question 4

    The passage is chiefly written to counter which of the following views?

    • A.

      That people sometimes notice favoritism in their own workplaces and say so when they are asked.

    • B.

      That nobody who has lost out in the competition for jobs and incomes could ever believe in merit.

    • C.

      That exposing rigged appointments is a reliable way of building public support for fairer hiring practices at work.

    • D.

      That belief in merit is held mainly by those who have succeeded and who need it to justify their position.

  5. The Traveling Bones

    It is often assumed that holy places are holy in advance. A saint dies on a certain hillside, or a vision appears at a certain spring, and the place is thereafter set apart; pilgrims arrive because the holiness was already there, waiting to be recognized. On this account sacred geography is a given, a map drawn by revelation that devotees can only discover. I want to argue that the map was drawn largely by exchange, and the best way to see it is to follow a single saint's body about.

    Teodric was a hermit who died in about the year 640 in a stone cell above a mountain lake, and for some decades he was venerated by the shepherds who had known him. The cell was not a destination. In 702 a bishop, who needed a saint for his new cathedral in the lowland city, had the body lifted from the grave and carried down the valley in a procession that, according to the chronicler, took eleven days and produced three cures. The cathedral thereby acquired a patron, and the city a reason to be visited. A tooth went next to a river-port monastery as part of a bargain over land, and its abbot built a chapel to receive it. A rib passed to a duke's wife, who wanted her new castle to be a place where prayers were answered; the castle chapel soon had a reputation for answering them.

    Consider what happened to the cell above the lake. If holiness belonged to the place, it should have kept it. The sources suggest otherwise: for nearly two centuries after the body was taken, the cell is hardly mentioned, and the path to it was overgrown. The one traveler who does mention it, in the tenth century, calls it a ruined place kept by a single goatherd. Its standing returned only in the twelfth century, when a monk brought back a small bone from the cathedral treasury and fitted it into the wall of the cell. The place where the saint had died became holy again by receiving a piece of him.

    I am not suggesting that anyone was cynical. The pilgrims believed, and the miracles credited to the relics seem to have been reported in good faith. Revelation and the experience of cure mattered enormously. But what the pilgrims believed was attached to bones that had been moved, bought, bargained over, and in at least one case stolen from a rival house, and a belief in a place that was fixed in advance is, in this case, a belief held in retrospect. Each shrine told a story about why it was where it was, and each story made the location sound inevitable.

    The conclusion I draw is that the sacred landscape of that region is a record of transactions: gifts to secure alliances, purchases to settle debts, thefts that rivals never forgave. The holiness did not stay put. It traveled, and where it was set down a holy place came into existence. To call this an economy is not to deny the sacred. It is to say that holiness, like any other valued thing, could be moved, and that those who moved it left a map.

    Question 5

    Which of the following questions does the passage most directly address?

    • A.

      How did particular places come to be regarded as holy, and was their holiness settled before any human exchange took place?

    • B.

      Why did the pilgrims of the early Middle Ages choose to travel such long distances to visit shrines in distant regions of the continent?

    • C.

      What became of the body of Teodric after the bishop removed it from its original grave above the lake?

    • D.

      Were the relics in the shrines of the region genuine, or were they forgeries sold to the credulous?

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