Both polygenesis and monogenesis supporters were equally racist in practice

Evidence

American intellectuals followed this debate between monogenesis and polygenesis in the same way students would follow the debates of their professors. And in following the racist debate, American intellectuals followed the racist debaters. American enslavers and secular intellectuals most likely lined up behind Lord Kames and other polygenesists. Abolitionists and theologians more likely lined up behind Immanuel Kant and other monogenesists. But these American polygenesists and monogenesists had no problem coming together to inflame public sentiment against England and dismiss their own atrocities against enslaved Africans. — Ibram X. Kendi, Stamped from the Beginning, 267

Categorization

• XREF: Shows the segregationist vs assimilationist split in embryonic form — both camps racist, differing only in the rationale. Directly usable for the reader’s three-way scheme.
• SEED: Angle: the unity of racist enemies across the species-line debate as a template for modern hereditarian vs cultural explanations of difference both being anti-Black.