If you think about the Foundations series, it was basically about this: studying the psychology of masses of people and predicting (and influencing) their behavior.
Wow, that's really great to read. I did not get this idea from the first Foundation much, although it was a little more prevalent in the second book. I got something rather different from Foundation: the idea that one with omniscience shares what is timely and relevant for the benefit of all.
Hari Seldon's psychohistory brings back fond memories.