Casta taxonomy assigned more categories to Indian-black mixing than other pairings

Evidence

The standard table of the range of racially revealing inscriptions can be broken into three kinds: white/Spaniard mixing with Indian, of which there are three variations; white/Spaniard mixing with black, of which there are four variations; and Indian mixing with black, of which there are eight variations. — David Theo Goldberg, The Threat of Race, 1091

Categorization

• SHARE: For a friend studying visual taxonomies of race: the asymmetry (3 white-Indian, 4 white-black, 8 Indian-black) shows the system’s deepest anxiety was reserved for the lowest-status crossing.
• QUESTION: Why did Indian-black combinations merit eight categories while white-Indian got only three? Suggests perceived instability or ambiguity at the bottom of the hierarchy.