Psychohistory was a scientific field known by various races in the galaxy.

It was a study of both psychology and sociology, which attempted to predict future events based on past actions. This allowed a psychohistorian to identify key decision points and individuals that will make those decisions. Due to the nature of the study, it was incapable of charting a single individual's actions but rather required a large galactic population in order for it to be effective.

The Seldon Institute of Psychohistory was an organization within the United Federation of Planets. (TOS novel: Preserver)

The concept of psychohistory was originated by Isaac Asimov in his Foundation stories and novels.