The expectations of one person influence the behavior of another, typically in a confirming direction. I would like to make three points about this statement. First, I argue that no other single hypothesis better captures the essence and spirit of social psychology. Second, I consider reasons why the expectation hypothesis has generated such an enormous amount of research across seemingly diverse fields. Third, I contend that the expectancy hypothesis is not a hypothesis at all but is rather a social fact, and a scientifically proven one at that.

The quintessential social hypothesis

According to Gordon Allport (1985), social psychology is the study of “how the thought, feeling, and behavior of individuals are influenced by the actual, imagined, or implied presence of others” (p. 3). One would be hard pressed to find a topic more archetypal of social psychology than interpersonal expectancy effects. Mind is the instigator of the expectancy process, yet the phenomenon itself involves some transfer between persons. Anyone who has struggled to define the proper unit for the statistical analysis of an expectancy study has grappled with the true heart of social psychology (“Is the teacher my unit of analysis, or the teacher-student dyad? Perhaps it is the number of classrooms that dictates my degrees of freedom?”).