This is a great topic! Thank you for starting the thread, Helo!
I've seen a few things that I would like to offer to the discussion. I preface this by saying my comments are about Black and White people specifically although I realize, as we all do, race and ethnicity encompass a much broader range of cultures than those two. But. I'm Black and PLove (wife) is White so that is my point of reference; I would feel disingenuous writing about other cultural experiences without firsthand knowledge.
Ok...so about Blacks and poly...
1. In my experience, Black people have poly arrangements as well BUT keep them in the closet because they fear judgment and ridicule, or just discuss them in different terms. Instead of calling it poly, a Black woman may just admit to having a number of "friends" that she keeps company with and who all know about each other. This same woman may also have a female lover, or a guy who is her "primary" but lives in another city and is cool with her dating other people because he does the same.
2. Minority groups are always striving to be a part of the mainstream in ways that the dominant group has already been able to enjoy for generations. So while White people have had the opportunity to take for granted strong, stable families, healthy communities, and generational wealth, Blacks have, largely, NOT been able to take part in these trends. So, many Blacks are still focused on the idea of having the "American Dream", which is getting married, having a family, and settling down into their own version of The Cosby Show. Its another reason why there were so few Black hippies: at a time when Blacks were trying to break IN to mainstream culture, these affluent, white teenagers were rebelling against
it. So, short answer: White people, being the dominant culture, can afford to explore poly because they have the security to do so while Blacks are still fighting to get their families and communities in order.
3. There is a lot of racism in the poly community! PLove and I have met a number of White people who made it clear by their actions and conversation that, while they were poly, dating outside of their race was still something that was taboo. We've run into the same shit with swingers; usually its a White couple that makes it very clear that they are absolutely not open to any other race but White. Hey, everyone has their preferences, so I can dig it. But if you're White and poly, I would ask how many times you've put yourself into spaces in such a way that you could actually make a real connection with Black people beyond the superficial one that most of us experience? In my experience, poly is extremely segregated. I know a number of Black couples/singles who are poly (or at least non-monogamous) but who only connect with other Black people; when PLove and I attended our local Poly Meet-up, I was the only Black person there.
4. IMHO, there is probably MORE polyamory practiced in the Black community than in the White community. Why? Because historically the Black community has suffered from greater levels of poverty and lack of resources, which would lead to, I would suspect, a natural inclination towards polyamorous arrangements. One guy taking care of multiple women, a woman with multiple partners, all to improve access to resources, safety, security, and the strength of the community. I may be completely wrong, especially since there are some studies that suggest minority groups actually tend to embrace more rigid, conservative values even MORE than their dominant counterparts.
In my personal experience, I was raised in a poor Black neighborhood in Pittsburgh. My parents were happily married BUT my father had a number of girlfriends in the community and my mother had one guy who she spent time with off and on. It wasn't that big of a secret but I didn't realize just how unusual it was until I got old enough to start dating and having sex myself. So, I imagine that, if my parents, who were older and Southern, were doing it back then...its not a new fangled thing in the Black community.