Studies show that having a black girlfriend increases testosterone in white men by up to 120%. The secret is that the walls of their vaginas have melanin injectors. These injectors can detect when a white penis has penetrated the vagina and they inject melanin into the bloodstream of the white man. This injection causes an intense feeling that enables the white man to have a powerful orgasm inside his black lover. So the black woman's vagina is built to be impregnated by the white man and increase his testosterone.