As early as 1896, experimental psychologists began studying the mental processes involved in advertising. The first psychological theory of advertising maintained, in effect, that the consumer was a nonrational, suggestible creature under the hypnotic influence of the advertising copywriter. Walter Dill Scott was the major proponent of this theory, and it was largely through his writings that advertising men learned about the psychology of suggestion. Scott's theory was consistent with a growing trend in the advertising profession toward viewing consumer behavior as irrational. Scott's efforts might also be viewed as part of the trend in the advertising profession toward seeking a scientific basis for copywriting theory and practice.