Have you ever encountered an example of someone belittling their *own *race/gender/sexuality rather than someone else’s? For example have you heard a woman disparage females as being “weaker”, or anyone stating that another race is superior to their own for whatever reason?
I think about 90% of stand up comedy falls under this description.
Then have you ever heard these sorts of opinions voiced in earnest, rather than in jest?
Didn’t Jimmy the Greek talk about Blacks being better at certain sports because of their feet? Or was it slavery?
I’ll google it…
Close, but not quite what I had in mind. If Jimmy the Greek ranted about how all Greeks are lazy and worthless, that would qualify.
Includes some other tidbits from other sports personalities. They all seemed serious, not joking.
Probably not exactly what OP was wanting
Missed while I was posting.
But, he did say that Blacks were better at something than his “race” more or less.
Closest I could come up with. 
I have seen people disparage their own race. I recall a Latino classmate tell me how all Latinos were poor and uneducated.
Yes, In high school I remember a girl saying “girls are not as smart as boys”.
I knew a women in college would not take ignore everything I said and only paid attention to my male counterparts.
I knew a girl who called all feminist s"femi-Nazis".and said women are “catty, mean, and two faced”.
So yes, self-bigotry does exists
My Asian friend says, “God, I hate Asians” every time he sees another Asian person doing something annoying.
To use a few famous examples, NOBODY hated Irish Catholics or looked down on them more contemptuously than Irish-American writers Jimmy Breslin and James T. Farrell.
It seems that every time I ask any woman who is a member of a relgious group who doesn’t let woman lead why they don’t consider women equal to men, I get the “oh, but that’s not a woman’s role” bullshit.
Not sure it’s quite what the OP had in mind, but I’m thinking of the many gay-bashing conservative politicians who were later busted having sex with underage male prostitutes or something like that. They hate themselves and their natural desires so much that they want to make all gays as miserable as themselves.
This happens all the time for all sorts of reasons. Who hasn’t heard of it?
Isn’t that usually called “internalized racism,” “internalized homophobia,” internalized sexism," etc.? I think that’s a more accurate descriptor than self-bigotry.
I’ve certainly heard of it - I was just interested in hearing people’s accounts of it.
That’s does sound more accurate, yes.
I have a biracial friend - mother white, father black - who struggled with racial prejudice against black men. She went to a mostly white school and was surrounded by white people, so she never really felt acclimated in the black community. She was estranged from her father and at one point his relatives kidnapped her so her father could see her… so she had this very scary, negative image of black men.
As a Gay dude, I am not proud of the fact that I have often referred to another guy as a “bitter little queen”…but when you hang around the Gay Bars long enough in your youth, you do meet some pretty nasty stereotypes. I think no matter what group you belong to, there is always a certain percentage of folks in your group who do make you all look bad.
That said, these are usually very isolated incidents/people and it is not like I run around generally disparaging about Gay guys. But sometimes you gotta call 'em as you see 'em. To pretend otherwise would be denying the fact that not everybody in your group is a shining example. Every group of every kind has their nutcases that fulfill every negative stereotype…luckily, they are usually a very small minority - but they are there.
There have been a number of well-known “self-loathing” gays. Robert Reed comes to mind. I could see this being a very common mindset into the 1970s or so - if the whole world hates what you are and you can hide it (as opposed to being obviously of a non-white race or a religion that has evident markers), transferring the hatred inward would be almost inevitable.
A black friend of mine was pretty openly prejudiced against other African-Americans.
I seem to recall that Jane Fonda’s (white) ex-husband said something about hoping for the end of the white race…
Ah, here it is: