It is because the two groups are from different spectrums, and black women in general are discouraged to date non-blacks (even if they can not find a black man as a suitor). There is also the attraction factor. Black women, for instance, are heavier and have ‘thicker’ bodies than Asian or white women. This body type is different than what most Asian men are used to because Asian women are very petite. Also, black women are generally taller or the same height as Asian men, and most women desire men that are taller than them. There are also factors of racism and cultural differences. An Asian man (like many non-blacks) may want to have sexual encounters with a black woman, but doesn’t want to settle down because it would go against his family’s wishes. Despite these reasons though, these types of relationships do exist in very small numbers — I am a perfect example. In Jamaica however, the coupling is so common nobody takes a second look. So I guess it’s partially a regional thing too.