The main idea of a passage or reading is the central thought or message. In contrast to the term topic, which refers to the subject under discussion, the term main idea refers to the point or thought being expressed. The difference between a topic and a main idea will become clearer to you if you imagine yourself overhearing a conversation in which your name is repeatedly mentioned. When you ask your friends what they were discussing, they say they were talking about you. At that point, you have the topic but not the main idea. Undoubtedly, you wouldn’t be satisfied until you learned what your friends were saying about this particular topic. You would probably pester them until you knew the main idea, until you knew, that is, exactly what they were saying about your personality, appearance, or behavior. The same principle applies to reading. The topic is seldom enough. You also need to discover the main idea.
1. As soon as you can define the topic, ask yourself “What general point does the author want to make about this topic?” Once you can answer that question, you have more than likely found the main idea.
2. Most main ideas are stated or suggested early on in a reading; pay special attention to the first third of any passage, article, or chapter. That’s where you are likely to get the best statement or clearest expression of the main idea.
3. Pay attention to any idea that is repeated in different ways. If an author returns to the same thought in several different sentences or paragraphs, that idea is the main or central thought under discussion.
4. Once you feel sure you have found the main idea, test it. Ask yourself if the examples, reasons, statistics, studies, and facts included in the reading lend themselves as evidence or explanation in support of the main idea you have in mind. If they do, your comprehension is right on target. If they don’t, you might want to revise your first notion about the author’s main idea.
5. The main idea of a passage can be expressed any number of ways. For example, you and your roommate might come up with the same main idea for a reading, but the language in which that idea is expressed would probably be different. When, however, you are asked to find the topic sentence, you are being asked to find the statement that expresses the main idea in the author’s words. Any number of people can come up with the main idea for a passage, but only the author of the passage can create the topic sentence.
6. If you are taking a test that asks you to find the thesis or theme of a reading, don’t let the terms confuse you, you are still looking for the main idea.
Directions: Read each passage. Then circle the letter of the statement that effectively sums up the main idea.
1. A number of recent books with titles like Raising Cain, Real Boys, and Lost Boys all focus on the same issue: Today’s teenaged boys are feeling more anxiety than ever before about their physical appearance. Bombarded by advertising featuring well-muscled, semi-clad young men, teenage boys are experiencing what teenage girls have been coping with for years. They are afraid that they cannot possibly live up to the media’s idealized image of their gender. Young boys below the average in height, weight, or both suffer the most. Often, they are brutally teased by their brawnier peers. Some react to the ridicule by heading for the gym and lifting weights. Yet even those who successfully “bulk up” don’t like feeling that they are considered worthless if they lose their hard-won muscle tone. Others, convinced that no amount of body building can help, often withdraw from social contact with their peers. This is their way of avoiding taunts about their size or shape. Still, they are understandably angry at being badly treated because of their body type. Although school psychologists generally recognize that boys today are having severe body image problems, they are at a loss about what to do to solve those problems.
a. More than in previous generations, teenaged boys are getting into body building.
b. Teenaged boys today are showing more anxiety about their physical appearance than did boys of previous generations.
2. In 1997, the U.S. Consumer Products Safety Commission reported that skateboarding injuries were up by 33 percent. Mountain climbing injuries were also up by 20 percent. Similarly, snowboarding injuries showed an increase of thirty-one percent. By all accounts, many Americans are having a love affair with risky sports; as a result, they are injuring themselves in ever greater numbers. One reason for the growing participation in risky, or extreme, sports has been put forth by Dan Cady, a professor of popular culture at California State University. According to Cady, previous generations didn’t need to seek out risk. It was all around them in the form of disease epidemics, economic instability, and global wars. At one time, just managing to stay alive was risky, but that feeling has all but disappeared, at least for members of the privileged classes. To a degree Cady’s theory is confirmed in the words of adventure racer Joy Marr. Marr says that risk has been “minimized” in everyday life, forcing people to seek out challenges in order to prove themselves. (Source: Karl Taro Greenfield. “Life on the Edge.” Time. September 6, 1999, p.29).
a. According to Professor Dan Cady if California State, many Americans yearn for the days when just staying alive was a difficult task.
b. More and more Americans are taking up high-risk sports; as a result, injuries from these sports are increasing.
Directions: Read each passage. Then complete the main idea statement begun on the blanks that follow the paragraph.
1. In several states across the nation, there has been successful drive to end “social promotion.” In other words, children who do not achieve the required score on a standardized test will no longer be promoted to the next grade. Instead, they will have to repeat the grade they have finished. Yet despite the calls for ending social promotion--many of them from politicians looking for a crowd-pleasing issue--there is little evidence that making children repeat a grade has a positive effect. If anything, research suggests that forcing children to repeat a grade hurts rather than helps their academic performance. In 1989, University of Georgia Professor Thomas Holms surveyed sixty-three studies that compared the performance of kids who had repeated a grade with those who had received a social promotion. Holms found that most of the children who had repeated a grade had a poorer record of academic performance than the children who had been promoted despite poor test scores. A similar study of New York City children in the 1980s revealed that the children who repeated a grade were more likely to drop out upon reaching high school. The call to end social promotion may have a nice ring to it in political speeches. Yet there is little indication that it does students any real good.
Main Idea: Across the country, many states have abolished the policy of “social promotion”
2. During World War I, a number of severe shortages alerted the world’s scientists to the need for synthetic, or man-made materials. Thus by 1934, a research team headed by Wallace H.Carothers had developed the first synthetic fiber, called nylon. As it turned out, the development of nylon had a surprisingly profound effect on world affairs. True, it’s first use was in fashion, and in 1939, the Dupont company began marketing sheer nylon hose for women. Nylons were a spectacular hit and sold off the shelves almost immediately. But they disappeared with the coming of World War II, as nylon became essential to the war effort. It was used in everything from parachutes and ropes, to insulation and coat linings. Sadly Carothers never witnessed the impact of his creation. He committed suicide two years before the first pair of nylons ever went on sale.
Main Idea: In 1934, Wallace H. Carothers developed nylon, the first synthetic fiber
Directions: Each paragraph is followed by a statement of the main idea that is not quite accurate or precise enough. In other words, it almostbut not completelysums up the main idea. Revise each statement to make it more effectively express the main idea.
1. Over the last two centuries, America’s soldiers have been given several nicknames, among them “yanks,” “grunts,” “doughboys,” and “Johnny Reb.” However, none of those nicknames has had the staying power of the nickname “G.I.” Derived from the words “government issue,” the term “G.I.” emerged in World War II and gave birth to its own masculine and feminine forms, “G.I. Joe” and “G.I. Jane.” It was even attached to one of the most famous educational bills in American history, the G.I. Bill. At one point, the military tried to rid itself of the name G.I. claiming that it dehumanized the people to whom it referred. Military manuals and pamphlets began substituting the supposedly more favorable term “service members.” But the public would have none of it. Newspapers, radio, television, and most importantly, World War II veterans themselves clung to the nickname. Particularly for the veterans of World War II, being a G.I. was a badge of honor, and they were not about to give up the name.
Imprecise Main Idea: Throughout the last two centuries, America’s soldiers have been given many different nicknames.
Revised Main Idea:
2. While she lived, the Mexican painter Frida Kahlo was known mainly as the wife of the famed muralist Diego Rivera. Yet in the decades since her death, Kahlo has become hugely famous in her own right and is probably now better known than her husband. In 1990, Kahlo became the first Mexican artist to break the one million mark at an auction. The vivid, self-portraits that Kahlo created in the thirties and forties continue to be widely sought after by collectors willing to pay high prices for her paintings. Although Kahlo is often described as a painter intent on exploring her own personal reality, many of her paintings include references to Mexico’s political and social history. It’s not surprising, then, that in 1985, the Mexican government publicly proclaimed her work a national treasure.
Imprecise Main Idea: Unfortunately, the painter Frida Kahlo spent her life in the shadow of her famous husband, the muralist, Diego Rivera.
Revised Main Idea:
Directions: In the blanks that follow each paragraph, write out what you think is the main idea.
1. In the 1870s, the Welsh explorer Henry Morton Stanley navigated the Congo river under the sponsorship of King Leopold of Belgium. Wherever he stopped, he made treaties with the African chiefs he encountered. As a result, when Stanley returned to Europe, King Leopold was able to take possession of an area eighty times the size of Belgium. Leopold promptly called the area the Belgium Congo and turned it into his own private goldmine, almost destroying the Congo in the process. Under Leopold’s rule, the Congolese were faced with impossibly high taxes and forced into slave labor. Agents of the Belgian government would give each Congolese family a basket to fill with rubber. If members of the family did not return the basket with the required number of pounds of rubber, their home would be burned to the ground. Anyone who rebelled would be put in prison. Meanwhile, Leopold grew enormously rich, squandering his blood money on yachts, mansions, and mistresses. To keep the Belgian people quiet, he also expended enormous sums on public works. Nevertheless, public opinion against Leopold and his vicious ways grew stronger. Ultimately he was forced to give up his stranglehold on the Congo, but not before millions of people had been imprisoned and thousands had died.
2. Computerized axial tomography, also known as the CAT scan, was developed in 1971. In its importance, the development of the CAT scan ranks with Roentgen’s discovery of X-Rays. The word “tomography” comes from the Greek word “tomos” meaning section or slice. In effect, the CAT scan allowed doctors to see into the body almost as if layers of it had been sliced away for better viewing. For the first time, it was possible to view soft tissue inside the skull, chest and abdomen without resorting to surgery. Thanks to the CAT scan, radiologists could now distinguish normal from clotted blood. They could also examine the ventricles of the heart without inflicting pain. Prior to the creation of the CAT scan, it had been necessary to pump air into the ventricles of the heart, causing the person undergoing the procedure intense pain.
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Last update of this page: Oct. 16, 1999