It has been over 10 years since we initiated work on our first series of
collaborative experiments. As graduate students, we had great fun
planning, conducting, and writing this research (Petty & Cacioppo,
1977). We enjoyed arguing with each other at our initial meeting in 1973
and have sub- sequently become best friends, but neither of us suspected
at the time that we would or could actively maintain a research
collaboration over the next decade, or that we would now find ourselves
in a position to write this monograph. As we note in Chapter 1, we began
our studies of persuasion at a time when social psychology was in
"crisis," and interest in research on attitude change in particular was
declining. As we write this, we are aware of six new volumes on
persuasion that are in press or in preparation and that should appear
over the next few years. In retrospect, it is not so surprising that
research on attitudes and persuasion would reemerge as a central concern
of social psychology. We believe that human feelings, beliefs, and
behaviors, whether in the domain of interpersonal relations (e. g.,
marriage, aggression), politics (e. g., voting, revolution), health (e.
g., following a medical regimen), or economics (e. g., consumer
purchases) are greatly influenced by the evaluations people have of
other people, objects, and issues. Furthermore, evaluations (attitudes)
are influenced by affect, cognition, and behavior.