The Double Consciousness of Black Identity

Many younger people that were, for example, born in the UK and might come from an immigrant family background experience a kind of double consciousness. And with this particular experience, they feel that they have no other home to return to if they feel demonized. I think this has led many of them to embrace their black identity as a kind of substitute for their sense of being rejected or the sense of being alienated from their British identity. But why wouldn't they cling harder to their Nigerian ancestry rather than a black racial identity? Or perhaps the Jamaican identity?