A September 2018 Article from The Sun (promulgated by Fox News) article is headlined:
EVIL BOTS Robots can become ‘racist and sexist’ all on their own, study finds
That study was based on a "give and take" system in which it ended up resulting that robots would donate to each other in small groups, even shunning others.
I haven't been able to see the whole study, but I'm skeptic about the claim because:
Although I'm no expert in robotics, I think that for a robot to be able to develop prejudices would very likely mean that robot brains would be already extremely near to a human one.
That they would share things in little groups doesn't necessarily mean that they do that because they develop the prejudice, maybe the own system favored that giving and taking in small groups would likely give bigger gain.
Anyway maybe robotics is already advanced enough for that, so I'm posting.
Have robots become racist and sexist?