i thought xenophobia is fear of outsiders? like ancient China, they didnt interact at all with the outside world

Well in the eighties this was already going on in the townships. Especially blacks with authority ie. Policemen and military personnel. They used to beat up on trouble makers and yet we were not allowed too. it was against the law. Trouble is the world find it difficult to believe that black people can hate one another, just ignorance.

It seems like a classism issue to me. They must feel that they are better than foreign blacks. I would assume that American blacks feel that they are better than African blacks as well since they have a better standard of living and are more educated.

No, xenophobia is not a cover-up word. It a real phoenomenon that has real implications for it's victims. There's no mass conspiracy to cover up racism among any racial group as it relates to this word. Xenophobia happens among many races, not just blacks. The xenophobic attacks in South Africa are, IMO, an extension of the far-reaching racism problem that's been propagated by both blacks, whites, and other races in that country. It seems to me like healing in South Africa is a long time coming.

Xenophobia is an economic phenomenon, first and foremost. The majority of people perpetrating these crimes are living in tumble-down shacks, with no job at all and the bare minimum of prospects for getting one, and living off the meagre income brought in by one family member. This doesn't excuse their actions in any way - but what happens is that the foreigners are often refugees from other African countries where they're even worse off, so they come here to SA and work their butts off at any job they can get, and end up prospering a little more often than their local neighbours. You can imagine how that stirs up feelings. Local people, especially younger people, understandably have dreams of prospering by getting real careers and making something of their lives - especially after decades of inequality under apartheid where people didn't have fair opportunities. They resent the fact that they aren't in a position to have those kinds of careers because they maybe couldn't afford tertiary education etc, and they're angry. Now imagine some Somali guy moves in next door and opens a little shop. He does well because he sells his goods for a few cents less than the other shops. He does this because 1] he saves on rent by sleeping in the shop, and 2] he's desperate to send money home to his family who rely on him, but his neighbours don't see it that way. They support his shop because he's cheaper, but then they resent his success. You can imagine how this tinderbox of a situation leads to violence. I find it incredibly sad and painful all round, especially given South Africa's troubled history and then our 'Rainbow Nation' status in recent years. But it's a complex situation. In the end, the solution is jobs, jobs and more jobs.