Vanishing Boundaries: The Religion of Mainline Protestant Baby Boomers, by Dean R. Hoge, Benton Johnson, and Donald A. Luidens (Westminster/John Knox, 272 pp.; $17.99, paper). Reviewed by Lyman A. Kellstedt, professor of political science, Wheaton College, Wheaton, Illinois.

Vanishing Boundaries is an important piece of contemporary social-science research that should be read by anyone interested in the future of Christianity in American society. If you have ever asked yourself why some churches and denominations prosper while others do not, this book provides some answers.

The subjects for the study were confirmands of a particular segment of mainline Protestantism, the Presbyterian Church (U.S.A.) (pcusa). Churches were selected randomly to represent all regions of the country and all sizes of church. Confirmand lists from the 1950s and 1960s were obtained from the selected churches, limiting the study to the baby-boom generation and its immediate predecessor, and individuals to be interviewed were randomly selected from these lists. Sherlock Holmes-style investigations tracked down the people selected, who were then interviewed by phone, 500 in all. Forty in-depth interviews were conducted in person. Cooperation on the part of the people selected for interviewing was high. The authors talk about their methods of research in an open and frank manner, and in the process increase confidence in their conclusions.

Hoge, Johnson, and Luidens find that the Presbyterian confirmands have scattered into eight groups-four distinct "churched" groups: "fundamentalist," pcusa, other mainline Protestant, and churches from all other denominations; in addition, there are four distinct "unchurched" groups: attenders but not members, members ...