In what follows I am talking about the process by which a false belief is created and sustained at a group level, and not about individual people.
Obviously, it would be plain silly (as well as wrong) to assert that PC is a mass primary delusion which happened to arise simultaneously among many individual people.
What I am talking about is the mechanism of PC delusion formation PC at the group level.
Individuals participate in the PC group delusion (indeed they are now forced to participate); but that is not its origin, nor is it individuals who sustain the process of thinking imposed by PC.
While some roots of PC are innate, and some trends of modernization can be traced back a long way (at least 1000 years, with acceleration from about 300 years ago) - nonetheless PC crystallized and grew to become large and powerful from the late 1960s.
People tend to forget how rationalist was mainstream Old Left political thinking up to the mid 1960s - it was essentially a highly intellectual, Marxist-based thing.
In the UK the dominant Leftism was from the Fabian society: an upper middle class led, meritocratic, non-revolutionary gradualism, based on the assumed superiority of the planned economy, the assumed superiority of bureaucracy over markets, and therefore nationalisation of all significant parts of the economy.
This was highly meritocratic, based on equality of opportunity (enforced by the state), and egalitarian in terms of economic distribution - the state would substantially equalize incomes.
There was a belief that economic hardship damaged life chances, and that there was therefore more talent among the poorer classes than was being allowed to emerge.
But for Fabians there was no question about the fact that people were themselves unequal in character and ability. Socialism was not about denying the obvious facts - it was about rewarding people more or less the same, and giving them the same life chances, regardless of their character and ability.
So Old Left socialism was limited in scope mainly to economics (at least in its aspired scope - in practice it became corrupted into totalitarianism) - and it was not necessarily, nor even usually, atheist - there were many Christian socialists.
The Fabians were not trying to build heaven on earth, merely trying to alleviate some of the more extreme suffering on earth.
So mainstream Fabian socialism was very different indeed from political correctness - although, as a matter of observation, many Fabian socialists became PC, went along with it, as it emerged.
The other strand of socialism came from idealist roots, in people such as William Morris, but further back the romantics.
However, it did not come from specific people, it was not primarily rational - it was an irruption of animism, of id, of the craving for connection with the world - it sought a society in which alienation would be abolished, a society of positive bliss where people could live naturally, at their fullest human potential.
It hated industrialisation, hated bureaucracy, hated rationality - it sought a situation where for everyone impulse and instinct could flow swiftly and unimpeded into action.
It was about remaking society as paradise upon earth; and when existing humans impeded this, it was about re-making humankind.
It was this strand of unreasonable, irrational, Utopian leftism which irrupted in the 1960s among the intellectual elite and which threatened to sweep away the Old Left.
But the Old Left was already in deep trouble, although few had yet realized it.
The moral force of the Old Left came from the idea that lower class people of brains and ability were being kept down, while upper class people - many or most of whom who lacked brains and ability - were ruling the country.
Simply from the perspective of efficiency this was undesirable.
However, by the mid-twentieth century (with improvements in psychometric testing) it gradually became clear that modern societies already had equality of opportunity, the meritocracy was already in place - or at least as equal as could reasonably be aspired to, in an imperfect world.
So Old Left socialism - if it was honest - had lost it main moral driving force.
At around the same time, or a bit later, the Old Left also lost its economic legitimacy; as it became ever-clearer that economic planning, the replacement of markets with bureaucracy, was less- rather than more- efficient.
So the Old Left were, as a movement, en route to electoral destruction - caught between the hammer of the idealistic Utopian New Left and the Right. The Old Left had no idealism, and they had no rationale - and they were rapidly losing their electoral base.
The New Left electoral base was not rooted in the working class/ proletariat - but in gathering all kinds of groups (a 'rainbow coalition') who felt (or could be made to feel) oppressed - and added these to the traditional proletarian (Trade Union) left, with its upper class Marxist leadership.
This involved systemic dishonesty - and it was from the mid-1960s that the Left became based upon dishonesty (not just accidentally dishonest, or corrupted into dishonesty - but dishonest at its deepest root.)
Political correctness emerged as a modus operandi between the Old Left and the New Left.
Although a rainbow coalition of the disaffected made electoral sense as a way for the Left to survive, there seemed to be no way that anything could possibly hold together groups whose interests were - in the end - mutually exclusive and even in the short-term were in conflict.
To survive, as it has, the Left evolved that group cognitive process which we call PC, which alternates between Old Left bureaucracy and New Left/ romantic Utopianism.
The psychological basis of the PC Left is simply, merely, being anti-Right - merely the idea that the Right is evil.
At an individual level this ascribed evil on the Right could be of many, contradictory origins - its fundamental basis might be economic oppression, racism, sexism, environmental destruction, hereditary aristocracy, free market libertarianism, some personal slight, nationalism, the soul-less materialism of the Right, the Christianity of the Right : the specific grudge does not matter, so long as the Right-haters continue to work together, vote together.
Nobody invented political correctness, but over a relatively short period its amazing explanatory power dawned on more and more people on the Left.
In order to mobilize passion, PC can talk like a 1960s hippie revolutionary; in order to get power and stay in power PC can act like a 19th century Prussian bureaucracy. It simply flips back and forth in response to threats from the Right.
PC will use whatever works to defeat the Right, here and now, in this particular situation, regardless of the implications - because none of the implications will be followed through but merely swept aside in the next fight.
PC is a bundle of tactics. But PC tactics do not ever add-up to a strategy.
PC is hard to defeat, and impossible to defeat rationally, because it is not aiming anywhere in particular in any sustained way - it is aiming to defeat the right and to keep-together its coalition in this fight.
Sometimes PC is anti-racism, sometimes anti-sexism; sometimes pro-worker, sometimes pro-shirker; sometimes it is nationalist, sometimes it is internationalist; sometimes pro-economic growth, sometimes engaged in wrecking the economy; sometimes it aims to cover society in a blanket of bureaucracy, sometimes it wants a society of utterly free and spontaneous individuals - and so on.
Each of these happens for a segment of time, then is followed (but not consecutively) by something else happening; and the earlier is pushed aside.
PC is like the evening news, and then and then and then - something shocking, then something inspiring, then some politics, then a bad person, then a funny item, then a bit of gossip - it never adds-up, it cannot be added up, nobody tries to add it up; it is just a means of attracting and holding attention.
PC is functionally just a means of attracting and holding-together a short-term effective anti-Right alliance.
These irreconcilable demands are not to be balanced, nor to be compromised, but instead a mode of disrupted social cognition is to be imposed in which apparently all of this is possible, or rather not-impossible.
Delusions are, at root, not about belief, but about a mode of thought, a style of cognition - they are rooted in thought disorder where consecutiveness is disrupted.
Political correctness is an insane mode of discourse. It cannot be argued-away because its mode of thinking is not rational.
If you argue rationally against PC you will be met by gut feelings, if you argue emotionally this will be discarded and forgotten, and you will be met by rationalist bureaucratic speak.
If you argue from the needs of proletarian workers, you will be met by the needs of immigrants and the underclass; but if you reverse the basis of the argument then PC will reverse its focus of concern.
PC knows that the Right is evil and that anything they do to defeat it here and now is justifiable.
That's it. PC is a delusional system which arose, evolved in order to preserve the power of the political Left; it must be intrinsically (not accidentally, not remediably) delusional (irrational, fragmented) in order to hold-together the disparate and conflicted members of the Old/ New Leftist rainbow coalition in their opposition to the Right; and the dishonesty of PC is an intrinsic (although unintended, because unperceived) by-product of this cognitive irrationality.