Social psychology has been defined as 'an attempt to understand and explain how the
thoughts, feelings, and behaviours of individuals are influenced by the actual, imagined, or
implied presence of others' (G. Allport, 1954a, p. 5). This widely accepted and often quoted
definition of social psychology (see Chapter 1) identifies a potential problem for the study
of social influence - how does the study of social influence differ from the study of social
psychology as a whole? There is no straightforward answer. Instead, social influence
research can be circumscribed by the sorts of issue addressed by social psychologists who
claim to be studying social influence.