Whether you like it or care to admit it or not Black culture is also semi closed. It may be because they share a society with a non exogamous culture and bear the social commentary of lesser than from slave societies and that carry the burden of housing our cross cultural siblings of the two major races.
Again trying to claim that because Indians are one way blacks must be the same way.
1. In Guyana we have a phenomenon. No one can tell you who is black and who is mixed. Benschop says that he is mixed but Granger claims a black identity. So where is this closed culture? We cannot agree with who is black and who isnt. We dont even agree as to what we should call ourselves. Arguing about "black", "African" (which only intellectuals use), "Afro Guyanese", with some older folks even insulted if you dont call them "negro".
2. Do we have an "African" culture in Guyana? No we do not, and in fact few Afro Guyanese even have the slightest interest in Africa. Afro Guyanese are culturally creole and do not believe that this creole culture is unique to them. You do not hear any "cultural appropriation" calls. Creole folk songs are seen as "Guyanese" as is the creole dialect and other cultural contributions of Afro Guyanese. We dont police our ethnic borders the way that other ethnic groups in Guyana do.
3. The bulk of the mixed people in Guyana are part black. Blacks dont have a history of rejecting their mixed relatives or disowning people because they marry outside of the race.
Racism is a fact among blacks, but claiming that its because they are socially or economically closed is a joke.
Until recently middle class blacks wanted to have nothing to do with the more African aspects of Afro Guyanese culture and there was much admiration for "advancing" the race. And you know what "good hair" is.
If blacks have a problem its that they dont have an ethnic identity defined enough to protect themselves against that very powerful Indian identity. They dont support each other in the way that Indians do. An Indian will support a person because that person is an Indian, and I have seen this with my own eyes. It wouldn't even dawn on a black Guyanese to support a fellow black, such thinking only beginning to develop when they arrive in the USA.