Several versions of ‘social Darwinism’ flourished in the late nineteenth and early twentieth century, along with ideologies derived from non-Darwinian evolution theories. They exploited discoveries of fossil hominids including Neanderthals and the Piltdown fraud to construct rival explanations of the emergence of human characteristics that might shape social development. The linear hierarchy of races erected in the nineteenth century remained the basis of many popular accounts, even though professional anthropologists began to turn their backs on it. Ideologies based on national or racial competition were advocated even by writers who did not accept the Darwinian theory of competition within populations. Fear of racial degeneration fuelled the eugenics movement’s calls for the elimination of ‘harmful’ characters, although the input from genetics encouraged an analogy with artificial rather than natural selection.

More than three decades of the ‘constructivist turn’ in IR has led to clear insights about what the field gained and lost as ‘norms’ moved from the margins to the mainstream. What happened to the pathbreaking theoretical and empirical claims of the late 1980s and early 1990s? The critical edge dropped out, and the field fractured into silos, while an Atlantic divide deepened. Norms got reduced to an analytical factor to be tested. Can renewed attention to critical and holistic aspect of norms, help the world to craft better responses to climate change or pandemics? Not until the field confronts embedded hierarchies built on racism. I explore this overarching claim about racial hierarchy through the historically rooted themes of rights, migration, and nationality. I stress that IR mistakenly builds on the assumption of domestic jurisdiction as a fundamental feature of the inter-state system, rather than as a constitutive norm specific to the early twentieth century. With a conceptual stroke, the discipline eliminates imperialism, in theory and practice. Contrary to conventional wisdom, I do not privilege 1945, or 1648; our genealogical travels concentrate on the 1920s. Even a cursory glance at the diplomatic record reveals persistently fierce contestation over race.

Long arrived in Jamaica in 1758 hoping to make money and to be able to return to England soon. The plantation would be the source of his wealth, and a settlement with his older brother Robert secured him in the ownership of Lucky Valley. Having speedily made a propitious marriage into the white elite, he devoted himself for the next eleven years to every aspect of the management of a sugar plantation, all of which he subsequently described in his History. He represents the planter’s life as one of constant work and anxiety, yet ‘smoothed by the allurements of profit’. He saw himself as the head of the enterprise, responsible at every level, and disavowed the skills of the enslaved. He acquired new enslaved labour, organized the plantation on the basis of gendered and racialized practices, bought new land and built new works, greatly increasing the production of sugar and rum. Foreseeing the likelihood of an end to the slave trade, he worried about the failure of enslaved women to reproduce themselves, which he blamed on them, thus threatening future prosperity. He proposed new practices to improve what was conceptualized as ‘breeding’.

In 1954, the great African-American painter Jacob Lawrence conceived of a remarkable series of paintings that would, in his words, “depict the struggles of a people to create a nation and their attempt to build a democracy.” Initially, he had in mind a grand narrative beginning with the “causes and events leading into the American Revolutionary War” and ending in the early years of the twentieth century. As finally executed, Lawrence’s Struggle series of panels (1954–1956) extended chronologically from the 1770 Boston Massacre to the aftermath of the battle of New Orleans in 1815. Lawrence thereby placed the Revolutionary War and the War of 1812 at the center of the path to American nationhood.

The last step in the ascent of the chain of being was from the apes (considered as the highest animals) to humans. In the eighteenth century the linear model of the chain was applied to this transition by depicting the non-European races as intermediate stages between the apes and the highest human type. Nineteenth-century anthropologists used various characters, especially skull size and shape, to give an appearance of scientific credibility to the supposed racial hierarchy. Early theories of evolution often treated the 'lower' races as relics of earlier stages in the origin of humanity. When evolution was represented as a branching tree, the concept of parallelism was invoked to imply that some branches of humanity had not advanced as rapidly up the scale as others. Europeans' sense of their own racial superiority was thus preserved in the post-Darwinian era by converting the chain of being into an abstract scale of mental development ascended by several forms but at different rates.