If I told you that this book is about the history of survey research in America, would you read it? If I told you that much of the book deals with Alfred Kinsey's reports on human sexuality, would that pique your interest?

Perhaps only a political scientist could say that the Kinsey chapters are not actually the best part of the book. Or, at least, other parts should be of greater interest since they better inform us about modern survey research. The ongoing fascination with Kinsey, however, speaks to an important theme in The Averaged American—how surveys can shape the public's perception, or misperception, of itself.

In her book, Sarah Igo tells Kinsey's tale alongside those of Robert and Helen Lynd, authors of the Middletown studies, and the first wave of brand-name pollsters—George Gallup, Elmo Roper, and Archibald Crossley. Igo explains how they were all in pursuit of the average, or representative, American, though each used a different methodology. Gallup and his contemporaries relied on the new, and seemingly magical, science of representative sampling. The Lynds chose the residents—or most of the residents anyway—of a single city (Muncie, Indiana) to stand in for all of America. Kinsey purported to lay bare, as it were, the sexual practices of the population by interviewing a large but decidedly nonrepresentative sample of Americans. Having spent his career studying the insect world, Kinsey “clearly believed that only by gathering tens of thousands of subjects would he be certain to capture the full range of sexual practices” (p. 221), much as entomologists seek out every last species, notwithstanding their share of the insect population. Kinsey thus made the same error that plagued the infamous Literary Digest poll of 1936, in which an oversample of Republicans led the magazine to predict that Alf Landon would beat Franklin Roosevelt in a landslide. Both Kinsey and Literary Digest were under the mistaken impression that size matters most—and thus privileged a large sample over a representative one.

For the Digest poll and another equally famous polling debacle, the miscall of the 1948 presidential election (remember “Dewey Defeats Truman”?), it is obvious why an unrepresentative, or biased, sample is a problem. When the subject is something other than presidential elections, bias is often undetected but no less significant. In the case of Middletown, the problem was not so much that a single city was chosen to be a microcosm of the entire United States. Rather, it was that Muncie did not represent America's heterogeneous population at all, as it was chosen specifically because it had an unusually high concentration of native-born whites. And, to make matters worse, the Lynds studiously avoided collecting data from or about the city's African American population. But at least they were upfront about who was excluded from their study. Kinsey, on the other hand, claimed to describe the sexual practices of mainstream Americans, while never mentioning the nettlesome fact that his subjects were not selected to be representative of mainstream America.

Even though Igo mentions these problems of bias, she could do more to underscore why they matter. By the end of the book, a reader unfamiliar with public opinion research might be left with the impression that the Lynds, Kinsey, and Gallup et al. used methods that, while different, were equally valid. But not all survey research is created equal, not if the purpose of a survey is to reflect what the public really believes, thinks, and does. Even if it sometimes fell short, Gallup and his contemporaries had a methodology capable of doing that; the Lynds and, especially, Kinsey did not.

A concern over representativeness is hardly arcane. As articulated by Sidney Verba in his 1996 presidential address to the American Political Science Association: “Random sample surveys are statistically sound, and they treat each individual qua individual the same…. Polls are thus an important tool for equal representation” (“The Citizen Respondent: Sample Surveys and American Democracy,” American Political Science Review 90 [March 1996]: 1–7). Since public policy decisions are often made on the basis of what the public thinks, or is perceived to think, survey researchers are obliged to ensure that their methodology accurately reflects the whole public, equally.

A concern over equal representation speaks to one purpose of public opinion research—compiling the opinions of the aggregated whole, or telling us what the “average American” thinks. Not only are surveys used to discern the opinions of the public as a whole, however; they also reveal the sum of the parts that comprise the whole. While pollsters once lumped us all together, now they seek to split us apart into myriad lifestyle tribes. Igo, however, asks the compelling question of whether public opinion research has not so much discovered our many tribes as created them. Pollsters are not merely in the business of passively reporting on the groups that define the American public. Often, they have constructed new groups and social identities. In Igo's words, survey research allows people to “place themselves in a spectrum of others, to evaluate themselves via social scientific categories, and even to discover a community in the numbers” (p. 278).

To use a contemporary example of just such a “community in the numbers,” consider how the public opinion industry has facilitated the emergence of evangelical Christians on the political landscape. It was Jimmy Carter who gave the term evangelical political relevance, which in turn led pollsters to begin reporting on the opinions and behavior of this heretofore unheralded group, cementing evangelicals' own identity as a voting bloc. Three decades have passed since Carter was the first presidential candidate to describe himself as a born-again Christian, and evangelicals are now regularly cited as a political force to be reckoned with. They were always there, but not until their discovery of a community in the numbers was their political potential tapped. Today, self-proclaimed leaders of American evangelicalism claim to speak for the millions of their “constituents” whose presence is only revealed in the polls.

Religion is only one such example of how such identities are formed. Similar stories could be told about the construction of ethnic and racial categories with newfound political salience, like Latino and Asian American.

The process by which pollsters construct such identities has enormous implications for both campaigning and governing, but it is subtle and not well understood by political scientists. One reason, perhaps, is that tracing such a process requires an historian's touch. Igo's vantage point as an outsider to the world of public opinion research gives her a different perspective than someone from deep within this world. Typically, public opinion research focuses on the trees—the latest theory, the newest estimator—but rarely covers the forest. This is very much a forest book, as it illuminates how public opinion research is handled once it leaves the hands of the academicians. The author reminds us that it is not always the most scientific survey that leaves the deepest imprint, as demonstrated by the legacy of the unrepresentative but provocative Kinsey studies. In doing so, she shows us how public opinion research is used and misused. And that alone is an important lesson, for pollsters and the public alike.