Five (plus or minus one): The point at which an assemblage of individuals is perceived as a single, unified group.

At what point is an assemblage of individuals perceived as a single, unified group? And how do demographic characteristics of these individuals influence perceptions of groupness? To answer these questions, we conducted four studies in which participants viewed sets of images that varied in the number of individuals depicted, and then identified the number of persons at which the assemblage was perceived to be a single, unified group. Across four studies, we manipulated the gender and race composition of the persons depicted. The results suggest that five (plus or minus one) people constitutes the point at which a collection of persons is perceived less like separate individuals and more like a single, unified group.

How is your day going? Reciprocity Norm in Everyday Communication.

In 6 experiments, we manipulated the length of a communication message to assess reciprocity norm-following behaviour during conversational interaction. In Studies 1 and 2, scripts of different length were used in an online chat, and chat logs were analysed. In Studies 3 and 4, participants e-mailed scripts that varied in length to acquaintances, and replies were analysed.