My immunization-against-persuasion research at the University of Illinois in the late 1950s, described in the preceding chapter, was followed by a half-dozen years at Columbia University (including a year at the Center for Advanced Study in the Behavioral Sciences) when my research focused on communication variables that increased persuasive impact rather than on those that induced resistance to persuasion. I have retained interest in attitude change ever since and have been often called upon to write handbook chapters and other reviews of work on this topic (see chapter 4 in this volume). Indeed, for a decade after my own empirical research moved to other topics, I was probably regarded as the “world's greatest authority” on the subject, until this numero uno title passed to Richard Petty and John Cacciopo, and to Alice Eagly and Shelly Chaiken.

The usual “persuasive communication” research paradigm involves presenting a persuasive communication from an external source that argues against the audience's initial attitude, to test whether some communication variable (e.g., source attractiveness, message style, etc.) has a theorized effect on how much attitude change is produced on the issue explicitly argued in the message. My own approach, going back to my graduate student days, has differed from this conventional approach in two main regards. Firstly, I have been interested in internally induced attitude change, that is, in changing attitudes, not by presenting new information from an external source but rather by using Socratic questioning or directed-thinking tasks to make more salient information already virtually present in the target person's own cognitive arena.