Former Sundown Towns Link to Higher Racial Bias Today

Data from 1.3 million participants shows that historical exclusion policies correlate with modern bias in U.S. counties.

Updated on Oct. 26, 2026 in Social Sciences

Former Sundown Towns Link to Higher Racial Bias Today

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Do you believe historical community practices still impact the social attitudes of your area today?

A recent study of 1.3 million White participants reveals that U.S. counties with a history of sundown towns exhibit significantly higher levels of racial bias today. Researchers linked these contemporary patterns to historical practices of exclusion that were prevalent between 1890 and 1968.

Why it matters

The findings suggest that historical local policies of racial exclusion have lasting consequences for societal attitudes. By mapping the legacy of sundown towns, the research illustrates how past discriminatory laws and restricted social contact continue to shape present-day racial bias.

Researchers analyzed implicit and explicit bias metrics from 1.3 million White participants collected between 2002 and 2024. The study compared current bias scores in former sundown towns against counties that never adopted such exclusion policies.

The players

Arizona State University

A public research university located in a community identified as a former sundown town.

University of Oklahoma

A public research university situated in a location with a history as a sundown town.

The details

Researchers utilized data from Project Implicit, an online platform that measures social attitudes through association tasks, to quantify racial sentiment. They define a sundown town as a community that historically barred African Americans from residing or staying within town limits after sunset. The team attributes the observed bias to long-term structural legacies, including discriminatory policing, local ordinances, and systemic barriers that limited interracial contact for generations.

1890-1968: The period during which most sundown towns emerged.
2002-2024: The period during which Project Implicit collected participant data.

The Tech Race

This research quantifies the long-term psychological impacts of structural exclusion programs from the 1890-1968 era. It situates modern bias against historical precedents to show how legacy policies maintain influence in current data models.

The findings highlight that geographic history remains a significant variable in understanding contemporary racial attitudes across the United States. Residents in regions with a history of exclusion may encounter different baseline social dynamics than those in areas without these historical constraints.

The takeaway

The research confirms that localized historical policies have persistent, measurable impacts on modern racial bias levels. Researchers and policy analysts should continue to track how these regional bias disparities correlate with ongoing demographic and economic changes in former sundown towns.