Psychohistory concerns individuals and groups of individuals. It is an art, not a science. It aims at understanding the psychic motivations for action and attitude. Its verity depends upon detailed examinations of specific individuals and some shared experiences or cultural myths, with the caveat that those with a shared experience do not necessarily have a shared reaction. Change is activated by individuals who actively object to a shared experience. The position that psychohistory is “the branch of mathematics which deals with the reactions of human conglomerates to fixed social and economic stimuli” is based on the false assumption that “fixed social and economic stimuli” can be discovered and that individual and group perception of the stimuli are identical. Let us take an example.
Lee Shneidman (Thu,) studied this question.