Acts of hatred and racism that occurred this election year laid bare the very worst consequences of our increasingly hostile political climate. The Anti-Defamation League documented a “significant uptick” in anti-Semitic social media attacks on journalists in 2016. Jonathon Morgan, who has studied the use of Twitter by ISIS, has demonstrated the increasing radicalization of the so-called alt-right, a fringe political ideology fueled by racism and white supremacy. According to the Southern Poverty Law Center (SPLC), the term ‘alt-right’ was coined by white nationalist Richard Spencer. And looking beyond threats on social media, the SPLC also documented a large spike in “hate incidents” following the election.*

These trends are repulsive and frightening, and we should shed light on them, particularly if they indicate a direct threat to safety. However, we must also look beyond flagrant offenses to focus on the subtle forces that have so firmly entrenched our country’s racial disparities.

Modest forms of prejudice and privilege can cause systemic damage, as evidenced by the work of Nobel laureate Thomas Schelling. Schelling, who shared the 2005 Nobel Prize in economics for his work in game theory, recently passed away after a distinguished career at the University of Maryland and Harvard University.

While reflections on Schelling’s career have focused on his contribution to US nuclear doctrine, Schelling also tackled important questions of discrimination and segregation. His work shows that we cannot afford to ignore the powerful impact of more subtle prejudices that are often overlooked.

In 1971, Schelling constructed simple simulations of a diverse population’s decisions on where to live. The simulations illustrate how some of the most persistent racial disparities are sustained not by the deliberate actions of overt racists, but by the institutional amplification of relatively modest levels of prejudice, preference, and sorting.

How mild preferences can lead to severe division

Consider a community composed of two groups: white and black residents. All residents are completely comfortable being neighbors with people of the other race. They only prefer that they are not in the minority in their immediate vicinity—a relatively mild prejudicial preference, and clearly far from an overt act of hatred or racism.

However, diverse communities are extremely difficult to maintain amid these preferences, particularly if one group is considerably larger than another. Whenever (in Schelling’s simulation) someone moves to avoid being in the minority, that move intensifies the pressure to move for members of the same group at the old destination and members of the opposite group at the new destination. Relocation to avoid being in the minority cascades until everyone is stably segregated.

Schelling’s work does not suggest that all diverse societies are doomed to segregation. If the different groups make up reasonably equal shares of the population, or if their preference to live among a majority is weaker, some integration may occur. People may also have a preference for diverse communities, and that preference would counteract some of the dynamics leading to segregation.

However, Schelling’s analysis still shows that fairly mundane prejudices can have divisive impacts, even if no one openly desires these impacts. This unique look at segregation suggests that complacency in the face of racial disparities—simply because they are not overtly racist—can be very harmful.

Schelling’s work echoes that of Urban Institute researchers who have examined America’s racial divides. His segregation simulation shows that place matters when we craft public policies aimed at addressing racial disparities. Schelling’s work also highlights the related problem of structural racism, where systemic and institutional practices reinforce racial disparities, sometimes without any overt racism at all.

Margaret Simms and Elaine Waxman note that the important thing to understand about structural racism is that “once these structures are in place, no one has to actively think about race, privilege, or discrimination for these privilege systems to disadvantage people of color.”

In these cases, it is essential to acknowledge the subtle nature of white privilege that drives disparities, even though overt acts of white nationalism dominate the headlines.

*This paragraph has been edited to better reflect the connection between the term "alt-right" and white nationalism.