Not sure if that was Jung....but maybe there was one of his books I didn't read...Wait! Maybe there was something in there...Oh yeah it was "collective conscious". Given that then there are probably sub groups..like "collective unconscious":-)
Short term prediction is very possible. There could be books on why it is and why it is so hard to accomplish. Once said...I believe that getting into a group mentality has a very bad affect of sensitive people. I know it was and still is a big problem for me. Suspect that is why gurus sit on a mountaintop....

"Matter follows thought."-Krishnamurti