Making social psychology experimental: a conceptual history, 1920-1970.

The historical emergence of a field devoted to the experimental investigation of effects identified as "social" required a radical break with traditional conceptions of the social. Psychological experimentation was limited to the investigation of effects that were proximal, local, short-term, and decomposable. A viable accommodation to these constraints occurred in the closely related programs of Moede's experimental crowd psychology and Floyd Allport's experimental social psychology. Later, Kurt Lewin attempted to provide a different conceptual foundation for the field by drawing on certain precepts of Gestalt psychology and the philosophy of scientific experimentation developed by Ernst Cassirer. These ideas were poorly understood and were soon replaced by a methodological regime in which a new generation of statistical procedures and experimental design shaped implicit conceptions of the social in social psychological experiments through such procedures as randomization and the additive combination of variables.