Gardner, I. C. (1935). The effect of a group of social stimuli upon attitudes. Journal of Educational Psychology, 26(6), 471-478.
http://dx.doi.org/10.1037/h0054820
The cumulative effects of a lecture, a story, and a "chalk talk," spaced a week apart, on the scores of junior high school students on the Peterson-Thurstone scale on Attitude Toward War, and on the scores of college freshmen on the Smith-Thurstone scale on Attitude Toward Prohibition, were determined. To measure these changes in attitude the two forms of each scale were used twice. It is concluded that the three social stimuli had a cumulative effect on the attitudes in the direction intended by the experimenter. (PsycINFO Database Record (c) 2016 APA, all rights reserved)