Psuedoscience

…professors and medical doctors offered scientific evidence that ‘race mixture’ contaminated Europeans, biologically and culturally, and gave rise to a population of mixed origins that was physically inferior and psychologically unstable. …At the same time, the vigour with which White men opposed ‘race mixture’ officially, especially for men of colour, was exceeded only by the fervour with which they practiced it privately…

Stephen Small’s (2001) ‘Colour, Culture and Class: Interrogating Interrracial Marriage and People of Mixed  Racial Descent in the USA’…