In this chapter we outline the background to dynamical social psychogy as it stood before the research described in later chapters of this book. This background will help readers who are not familiar with either social psychology or complexity science to follow those chapters more easily. It will focus on two domains within dynamical social psychology: social influence on opinion formation and the concept of self/ It will also consider three aspects of dynamical social psychology that set it apart from previous theories of social psychology: the effect of the degree of coherence between the elements of a system, which explains the different behaviors we see under different circumstances, how emotions regulate other psychological systems, and the drive to minimalism, by which behavior which appears to be complex may be understood from a model of the underlying elements interacting under simple rules.