psychohistory

Short definition from Wiktionary

Noun

1. 1
   The scientific study of psychology and motivation in history.
2. 2
   A fictional mathematical statistical science of large population dynamics, where mathematical models can predict general futures, based on activities of quadrillions of individuals. The fictional science first occurs in Asimov's 1950s Foundation series, and has since been picked up by other authors for other works.