Is there a name for an ideology that says all social and economic problems can be solved through mass psychology? You could call it psychohistory perhaps, but there's got to be a newer term. Seems like it's the dominant ideology of a variety of technocrats.
Yes there are psychological aspects to governance but more and more it's becoming the only solution to all problems. Obesity is skyrocketing? It's the psychology. People don't like unlimited immigration? Get out the mass psychology. People perceive that inflation is out of control. Get out the mass psychology. Market is down. Employ mass psychology. People don't give a crap about a war that they have no stake in. Mass psychology. I guess propaganda works and it's very cheap, lol.
Public Relations - Edward Bernays [0]
Propaganda - Edward Bernays in 1928 [1]
Public opinion - Walter Lippmann 1947 [2]
[0] https://en.wikipedia.org/wiki/Public_Relations_(book)
Psychohistory is already a study of the past and why it happened the way it did, so maybe it could help answer your question, but it isn’t the ideology you’re seeking.
There is a reason that advertising and media influence is everywhere, it is a cheap and has a decent return on investment, whether that is actual revenue or just a shift in people’s perspective.
You may be thinking of Nudge Theory
something involving ppl following whatever the political or media firestorm of the moment is, and most ppl more likely to just follow whatever the party line is?
... I mean, in this case, it's a problem being _caused_ by mass psychology (that's what advertising is).
I think it’s traditionally called advertising.
On this subject I highly recommend the documentary "the Century of the Self" (produced by Adam Curtis for the BBC). It explores how Sigmund Freud's theories about the unconscious mind were used by his nephew Edward Bernays to create modern public relations and consumer culture. The documentary shows how corporations and governments learned to manipulate mass desires using psychological techniques, transforming democracy from meeting people's needs to managing their wants through consumption and marketing.
The entire doc is on Youtube: https://youtu.be/GFwDc17WZ-A