In 1999 the social constructionist Kenneth Gergen... — Joshs
Constructivism claims that all assertions of supposed facts are in actuality just social constructs... — Pfhorrest
As I understand it, social constructionism is the study of *which* and *how* social constructs are shared. Social constructivism is the theory *that* knowledge is socially acquired. They are not quite the same thing. The usual dismissal of social constructivism does not hold here.
I'm not sure that dismissal is ever generally valid even of constructivism. At root it is about how we learn things through social interaction. Whether by lecture, by book, by conference or by journal, science is a social endeavour in which each individual acquires knowledge through interaction with others. If that society has some bad assumptions or biases, the individual will invariably learn those too. The classic, and perfectly valid, constructivist case in point is Freud.
Strong social constructivism claims that most or all scientific knowledge is like this, while others are more interested in the extent to which this holds in the harder sciences. The former are obviously bonkers.
Social constructionism by contrast takes a social construct as its starting point, for instance an historical account of money, or systems of morality. It is the objects themselves that are of interest, not how knowledge is transmitted (although how knowledge is transmitted *into* constructs is relevant).
Unless you believe in divine revelation or some such, you'd probably agree that, to some extent, our morals are derived from our interactions with others: how we are taught by our parents, our teachers, our clergy, our peer groups and the media. As Pfhorrest knows, I actually don't think that morality is fundamentally like this, rather what we do with our morality is *altered*, rather than created, by society. We have built in moral rules, but we learn exceptions to those rules through social interaction.
Pfhorrest is a moral objectivist insofar as he believes there is exactly one correct answer to all moral questions but I don't think relativism versus objectivism is particularly relevant here. There may indeed be correct answers to moral questions, but that makes no odds to someone who learns *these particular moral rules* from their interactions. One can have a socially constructed morality and still be right or wrong. A strong social constructivist would say that objective moral truths have little to no influence on the moral rules people learn, and I think they'd be close to being right.
Like social constructivism, identity politics can yield a spectrum of claims. Eddie Izzard recently changed his (past) preferred pronoun to she (present), but said she doesn't care which people use. This is identity politics -- Izzard had established a preferred policy regarding her identity -- but it is not the sort of "fascist" identity politics that the right-wing like to accuse people like Izzard of. What are like that are those who would not only be outraged if someone now called Izzard "he", even though she's fine with it, but would be outraged that I referred to her past pronoun as "he" (a la dead-naming). Like strong social constructivists, these have a technical name: assholes.
The historic reason for identity politics is that some social constructs regarding people are harmful. Racism, misogyny and homophobia attempt to establish a natural order with straight white heteronormative people at a supremum and different people at lower strata. Such schemes are oppressive. Since these people are not open to integration and will support the perpetuation of oppressive structures, usually while denying they exist, the oppressed reassert their identities as positive qualities to challenge normalised constructs with negative connotations.
Identity politics is a social construct that is really the flip side of another, oppressive social construct. Gay pride is not an obviously useful construct except in the context of (especially religiously-fuelled) homophobia. Likewise black pride, black power, and BLM.
The problem is that these counter-oppressive identity politics can end up looking as oppressive as the social constructs they sought to challenge, and they often do so by confusing legitimate criticism of new forms of oppression with the original oppressive constructs. Two cases in point are people's reluctance to criticise Israel and the accusations of anti-Semitism they receive when they do, and their reluctance to criticise the excesses of feminism (such as a recent call to presume men guilty until proven innocent) for fear of being accused of misogyny.
If there's a common theme here, it's that sound ideas run amok, and vested interests use this as a means of dismissing the sound idea along with its extreme and absurd conclusions. Or, more briefly, there's assholes of all sizes.