The Implicit Associations Test of Racial Bias and Police Lethal Force Behavior

Research Study Sponsor:  SSHRC 

Funding for this project was provided by a grant from the Social Sciences and Humanities Research Council of Canada (SSHRC-IDG 430-2016-01227), which funded data collection. However, SSHRC had no other involvement in the conceptualization, design, analysis, decision to publish, or preparation of this manuscript.


Title: The Implicit Associations Test of Racial Bias and Police Lethal Force Behavior: An Ecologically Valid Study


Rising public concern regarding police Use of Force (UOF), particularly the use of lethal force on racialized community members, has stimulated research examining the prevalence of police shootings and speculation about the causes for these shootings. Racial bias, both at the individual officer level and of the communities in which they work, have been proposed as factors underlying the racial disparities in police shootings in North America. However, research based on lab studies or correlational public data are inconclusive – some studies actually claim to show a ‘reverse racism’ effect where white police officers are less likely to shoot Black individuals. We are testing that assumption in an ecologically valid experiment with police officers.


Furthermore, academic findings and media attention have motivated law and public policy makers to recommend new legislation and, in at least one case, screening procedures, for the purpose of detecting racial bias. For example, in July 2017, following the official Inquest into the shooting death of Andrew Loku in Toronto Ontario, the Ontario Office of the Chief Coroner recommended that it should be mandated that all police officers be tested for implicit racial bias (via the Implicit Association Test or IAT developed by Greenwald, McGhee & Schwartz, 1998) as part of initial screening (pre-hiring) and at requalification training annually (OCC, 2017).


Given the gravity of police shootings it is not surprising that policy recommendations are being made based on the available literature on implicit bias and tests of bias, such as the IAT. However, to date, there are no studies available that examine if the IAT can be used to predict racially biased police shootings among officers outside of the laboratory context.


We present novel data examining the utility of the Implicit Attitudes Test (IAT) to predict racialized police shooting behavior among police and discuss the potential implications of enacting policies such as using the IAT as a screener before hiring officers and at annual requalification assessments, as recommended by the OCC (2017).


Racial bias and lethal force errors among Canadian police officers.

Scientific examination of racial disparities in police shootings shows conflicting evidence of anti-Black, anti-White, or no racial bias. Experimental studies that attempt to control for extraneous factors often lack ecological validity and have inconsistent approaches for measuring racial bias. Given the mounting outcry for police reform, including recommendations for racial bias screening and training, clarifying the relationship between observable lethal force behaviors and implicit racial bias is an urgent matter. Building on limited extant literature, the present study examined racial disparities in shoot/no-shoot decision-making among Canadian police officers (n = 187) during their service’s annual recertification assessment that manipulated suspect race (Black or White) in otherwise identical scenarios. Lethal force errors were compared to implicit racial bias scores on the Implicit Association Test (IAT) and other demographic variables including officer sex, age, years of experience, and race. We found no statistically significant difference in error rates for simulations featuring a Black or White suspect for shoot (2.5%, 3.1%, respectively) or no-shoot scenarios (4.6%, 3.0%, respectively). Lethal force errors were not predicted by suspect race, extent of autonomic arousal, or IAT scores. However, the absolute frequencies of lethal force errors were greater in scenarios featuring Black suspects. The current findings suggest that widespread reform to police training is urgently needed to reduce racial disparities in use of force (UOF) and lethal force errors overall.

Impact Statement

Public Significance Statement—Academic research in psychology presents conflicting evidence for anti-White, anti-Black, and no racial bias. Further, lay popularity of the Implicit Association Test (IAT) has informed public policy recommendations to use the IAT as a screening tool for unconscious racial bias among police in Canada. The present study reveals anti-Black biases in police shooting errors that align with North American population studies showing anti-Black bias, but which are not statistically significant compared to scenarios featuring White suspects. Our findings do not support using the IAT as a screening tool for predicting racially biased shooting behavior among police.


Photo owned by Andersen

Office of the Chief Coroner, O. (2017). Verdict of coroner’s jury re: Andrew Loku, July 5, 2015. Retrieved from