During the recent war social psychologists were called upon to conduct research on many problems of importance to the war effort. Many of the data obtained in these research projects had significance and interest only in the immediate situation for which they were collected. Some findings, however, contribute information to basic or recurring problems of social psychology. In order to illuminate some of the basic processes involved in the induction of mass behavior, this paper draws upon the extensive program of wartime research conducted for the War Finance Division of the United States Treasury Department by the Division of Program Surveys of the Department of Agriculture. The immediate aims of the research program were to help guide policy decisions in the development of a program of inflation control through the sale of Saving Bonds. Due to the large number of separate studies drawn upon for data in this paper, it will not be possible to describe in each case the exact research methods employed. In general, the data are all drawn from intensive, open-ended interviews conducted with a representative sample of the population in question. Sampling methods employed were those known as ' area ' or 'proportional' sampling. Many research workers were involved in the collecting of these data, and without the contributions of all of them the studies would not have been possible. The author of this article was in charge of the total program.