White police officers in Chicago are far more likely than their Black counterparts to stop, arrest or use force against Black civilians, and the disparity is more pronounced in the city’s highly segregated majority-Black neighborhoods, according to a study published Thursday in Science. The study’s authors say the findings suggest more diversification in hiring could present an avenue for reform, but some social scientists and activists disagree. The city has had diversity programs in place since the 1960s.

The researchers compiled data from 2012 to 2015 on Chicago Police Department (CPD) officers’ race, ethnicity and gender, as well as stops, arrests and use-of-force incidents. They only analyzed records for patrol officers (or “beat” cops), excluding others in specialized units that might, for instance, be policing gangs. White cops were far more likely to use force during an arrest than Black or Latinx officers, and male police were more likely to use force than their female counterparts.

While there was no significant difference in how many violent-crime arrests officers made, Black and Latinx cops made far fewer stops for “suspicious behavior” and registered fewer arrests for petty crimes such as drug possession than white officers did. “That tells us there’s discretion somewhere in that process, and they’re exercising that discretion,” says study co-author Dean Knox, a computational social scientist at the University of Pennsylvania. “And if there are best practices in policing, both officers”—whether Black or white—“can't be following them.”

“The fact that we’re comparing officers working in the same circumstances and we’re seeing one group of officers use force more often, even though the conditions on the ground are the same, is troubling,” adds study co-author Jonathan Mummolo, a political scientist at Princeton. “And I would think that police departments would want to investigate that.”

Graphs show how increased diversity among police might affect how often they stop or arrest people or use force.
Credit: Amanda Montañez; Source: “The role of officer race and gender in police-civilian interactions in Chicago,” by Bocar A. Ba et al., in Science, Vol. 371; February 12, 2021

Cassandra Chaney, a Black families’ scholar at Louisiana State University, and a co-author of Police Use of Excessive Force against African Americans (Lexington Books, 2019), who was not involved in the research, was not surprised at the results. In comparison to white officers, Black cops, Chaney says, are less likely to hold biases that associate Black people with criminality. “One reason is that Black officers have lived in their Black skin all their life, and have dealt with racism,” she explains. Black officers are also more likely to perceive Black civilians’ basic humanity and to develop relationships with the residents of Black neighborhoods they patrol. “Even if a Black person is committing a crime, they’re able to see their totality instead of just reducing them to whatever behavior they’re engaging in,” Chaney adds. Florida A&M University sociologist Ray Von Robertson, Chaney’s book co-author, says that disparities in arrest rates and incarceration of Black and white drug users who consume drugs at similar rates suggest that white officers exercise restraint with white civilians. He adds that Black police officers, fearing harsher punishments for misconduct than their white counterparts may face, likely avoid risky behavior.

It is unclear how the results of the new research apply to other cities, given Chicago’s long history of tensions between civilians and the police. But study co-author Bocar Ba, an economist at the University of California, Irvine, says the research still provides a template for evaluating reform efforts. “What is needed is more data transparency, access to institutional details, and researchers from all across the board,” Ba adds. Chicago Police have long resisted independent efforts to examine the department’s internal operations. Citizen data projects have filled gaps by compiling data on use of force, torture and killings by police. A lawsuit by one such organization, the Invisible Institute, compelled the release of much of the data in the new study.

The CPD’s first efforts at fostering diversity in hiring began in the 1960s, says Simon Balto, a historian at the University of Iowa who wrote Occupied Territory: Policing Black Chicago from Red Summer to Black Power (University of North Carolina Press, 2019) and was not involved in the new study. A reform-minded superintendent and a lawsuit by the Afro-American Patrolmen’s Association drove the CPD to recruit more Black and Latinx officers. But Balto asserts that little changed in Chicago as the police force grew more diverse. “I’ve seen no evidence that changing the racial composition of the police force, at least at that point in time, resulted in particularly meaningful changes in the larger framework of how policing operated within communities of color,” Balto says.

In a statement to Scientific American, CPD spokesperson Don Terry says the department has expanded a training program in which neighborhood residents teach recruits about the communities they will be patrolling. The department also requires officers to undergo annual training in implicit bias, or unconsciously held stereotypes and prejudices. “Ensuring that our officers reflect the diversity of Chicago’s communities is critical to public safety and constitutional policing,” Terry says. A 2018 Chicago Tribuneanalysis found that diversity hiring efforts had not resulted in a significant increase in the number of Black cops in the department; in fact, the percentage of Black officers had decreased. In 2020, the Chicago Office of the Inspector General reported the proportion of Black officers is likely to further decrease as officers retire. The department is still under a federal consent decree stemming from the 2014 murder of teenager Laquan McDonald by a Chicago police officer; the administration of then-Mayor Rahm Emanuel did not release a dashboard camera video of the shooting until ordered to do so by a Cook County judge.

Whether diversity efforts and sensitivity training can reform the department—or if police departments can be reformed at all—remains an open question. Chaney says having more Black officers in majority-Black communities can help. “But you have to put Black officers in there who are actually serving with heart for the communities they’re policing,” she adds.

Damon Williams, co-founder of the #LetUsBreathe Collective, a police abolitionist organization based in Chicago’s Back of the Yards neighborhood that is campaigning to defund the CPD’s $1.7 billion budget, says the claim that hiring more Black police officers improves policing is part of a larger push to protect “irredeemable” institutions—namely, police departments. “I don’t think that these studies actually get us any closer to centering or repairing the actual harm” caused by police misconduct, Williams says. “I do think it is obvious that Black officers will tend to make better individual choices and be slightly more discriminate,” he adds. “But that does not correct or engage what racism is. Racism is not about the temperaments or choices of individual actors. It is a structural dynamic.”

Balto says reforms oriented around individual behaviors are unlikely to work. “The institution of policing remains fundamentally racist,” he says. “On the one hand, you do have a net positive [with Black police] of fewer stops, arrests, and use of force when you have a more diverse police force. But you still have a police force that is still operating within a racist superstructure. Part of the challenge is to rethink the very nature of the structure of public safety, because the police don’t have a good track record of ensuring public safety.”