What works to reduce police brutality

Psychologists’ research is pinpointing the factors that lead to overly aggressive, biased policing—and intervention that can prevent it

police in riot gear

When the Las Vegas Police Department applied a psychology-informed “hands off” policy for officers involved in foot chases, use of force dropped by 23%. In Seattle, officers trained in a “procedural justice” intervention designed in part by psychologists used force up to 40% less. These are just a few examples of the work the field is doing to address police brutality.

“There’s much more openness to the idea of concrete change among police departments,” says Joel Dvoskin, PhD, ABPP, a clinical and forensic psychologist and past president of APA’s Div. 18 (Psychologists in Public Service).

That shift is backed by support from the public. Since 2016, the share of Americans who say that police

Psychologists have already played a critical role in the reform process—from collecting data on biased police stops, searches and use of force to designing and delivering interventions that reduce the chances that police will rely on stereotypes, for instance by limiting the amount of discretion officers have during searches.

Now, psychologists are promoting those interventions to more police departments, conducting research to determine how well they work and continuing to collect and organize data on police behavior and department culture.

Criminal justice—police, courts, prisons—has been called an evidence-free zone,” says Tom Tyler, PhD, a professor of psychology at Yale Law School and an expert in the psychology of justice. “People in positions of power tend to make policy decisions based on intuition and common sense—presumptions that we as psychologists recognize are often in error.”

“What’s really needed is an evidence-informed model of criminal justice,” he says. “And a lot of that evidence can come from psychologists.”

Psychological research in action

In 2015, President Obama’s Task Force on 21st Century Policing reviewed scientific data on policing, recommending major policy changes at the federal level to improve oversight, training, officer wellness and more (Final Report of the President’s Task Force on 21st Century Policing, 2015).

Federal efforts have slowed in recent years, with most changes happening at the local level. But with around 18,000 police departments nationwide, that response has been fragmented and inconsistent (National Sources of Law Enforcement Employment Data, Bureau of Justice Statistics, 2016).

Still, psychologists have forged ahead with efforts that are making a difference. One key contribution involves spurring policy changes and interventions based on psychological insights.

“One of the most influential approaches coming from psychology is training in procedurally just policing,” says Calvin Lai, PhD, an assistant professor of psychological and brain sciences at Washington University in St. Louis.

That approach aims to increase the public’s trust in police by drawing on psychological research on justice and fairness. It involves teaching officers strategies such as explaining to citizens why they’ve been stopped and how it will benefit public safety (Principles of Procedurally Just Policing, The Justice Collaboratory at Yale Law School, 2018).

“We know that the policing model of using force to compel compliance lowers the crime rate but does not build trust,” says Tyler, who has developed and studied models of procedurally just policing. “The crime rate has declined about 75% in the last 30 years, but public trust in the police hasn’t increased at all.”

His research has shown that what community members really want is for police to treat them with respect and to give them a voice—a chance to explain their situation before action is taken. People also want to know that police are sincere, care about the well-being of their community, and act in an unbiased and consistent way—for example, by explaining the rules they use and how they’re applying them.

A study in Seattle randomly assigned officers to receive training in procedurally just policing, leading to a reduction in use of force of between 15% and 40%, depending on the situation (Owens, E., et al., Criminology & Public Policy, Vol. 17, No. 1, 2018).

“It seems to be doing what we’d hope in terms of promoting better relationships between police officers and community members,” says Lai.

The Center for Policing Equity (CPE), led by psychologist Phillip Atiba Goff, PhD, of Yale University, has also led a number of psychology-driven policy changes in police departments around the country. In an effort to cut down on high-adrenaline encounterswhere police officers are more likely to rely on stereotypes—Goff urged the Las Vegas Police Department to bar officers involved in a foot pursuit from handling suspects when the chase ends. The policy led to a 23% drop in use of force at the department, an 11% reduction in officer injury and a simultaneous drop in racial disparities in use of force data. CPE has also pioneered efforts to recruit racially and ethnically diverse officer candidates and to make immigration enforcement more consistent.

Another key area that psychological interventions target is

police in riot gear

When the Las Vegas Police Department applied a psychology-informed “hands off” policy for officers involved in foot chases, use of force dropped by 23%. In Seattle, officers trained in a “procedural justice” intervention designed in part by psychologists used force up to 40% less. These are just a few examples of the work the field is doing to address police brutality.

“There’s much more openness to the idea of concrete change among police departments,” says Joel Dvoskin, PhD, ABPP, a clinical and forensic psychologist and past president of APA’s Div. 18 (Psychologists in Public Service).

That shift is backed by support from the public. Since 2016, the share of Americans who say that police use the right amount of force, treat racial and ethnic groups equally and hold officers accountable for misconduct has declined substantially, according to the Pew Research Center (Majority of Public Favors Giving Civilians the Power to Sue Officers for Misconduct, 2020).

Psychologists have already played a critical role in the reform process—from collecting data on biased police stops, searches and use of force to designing and delivering interventions that reduce the chances that police will rely on stereotypes, for instance by limiting the amount of discretion officers have during searches.

Now, psychologists are promoting those interventions to more police departments, conducting research to determine how well they work and continuing to collect and organize data on police behavior and department culture.

“Criminal justice—police, courts, prisons—has been called an evidence-free zone,” says Tom Tyler, PhD, a professor of psychology at Yale Law School and an expert in the psychology of justice. “People in positions of power tend to make policy decisions based on intuition and common sense—presumptions that we as psychologists recognize are often in error.”

“What’s really needed is an evidence-informed model of criminal justice,” he says. “And a lot of that evidence can come from psychologists.”

Psychological research in action

In 2015, President Obama’s Task Force on 21st Century Policing reviewed scientific data on policing, recommending major policy changes at the federal level to improve oversight, training, officer wellness and more (Final Report of the President’s Task Force on 21st Century Policing, 2015).

Federal efforts have slowed in recent years, with most changes happening at the local level. But with around 18,000 police departments nationwide, that response has been fragmented and inconsistent (National Sources of Law Enforcement Employment Data, Bureau of Justice Statistics, 2016).

Still, psychologists have forged ahead with efforts that are making a difference. One key contribution involves spurring policy changes and interventions based on psychological insights.

“One of the most influential approaches coming from psychology is training in procedurally just policing,” says Calvin Lai, PhD, an assistant professor of psychological and brain sciences at Washington University in St. Louis.

That approach aims to increase the public’s trust in police by drawing on psychological research on justice and fairness. It involves teaching officers strategies such as explaining to citizens why they’ve been stopped and how it will benefit public safety (Principles of Procedurally Just Policing, The Justice Collaboratory at Yale Law School, 2018).

“We know that the policing model of using force to compel compliance lowers the crime rate but does not build trust,” says Tyler, who has developed and studied models of procedurally just policing. “The crime rate has declined about 75% in the last 30 years, but public trust in the police hasn’t increased at all.”

His research has shown that what community members really want is for police to treat them with respect and to give them a voice—a chance to explain their situation before action is taken. People also want to know that police are sincere, care about the well-being of their community, and act in an unbiased and consistent way—for example, by explaining the rules they use and how they’re applying them.

A study in Seattle randomly assigned officers to receive training in procedurally just policing, leading to a reduction in use of force of between 15% and 40%, depending on the situation (Owens, E., et al., Criminology & Public Policy, Vol. 17, No. 1, 2018).

“It seems to be doing what we’d hope in terms of promoting better relationships between police officers and community members,” says Lai.

The Center for Policing Equity (CPE), led by psychologist Phillip Atiba Goff, PhD, of Yale University, has also led a number of psychology-driven policy changes in police departments around the country. In an effort to cut down on high-adrenaline encounters—where police officers are more likely to rely on stereotypes—Goff urged the Las Vegas Police Department to bar officers involved in a foot pursuit from handling suspects when the chase ends. The policy led to a 23% drop in use of force at the department, an 11% reduction in officer injury and a simultaneous drop in racial disparities in use of force data. CPE has also pioneered efforts to recruit racially and ethnically diverse officer candidates and to make immigration enforcement more consistent.

Another key area that psychological interventions target is implicit bias, which has been documented across a range of domains and populations (State of the Science: Implicit Bias Review, Kirwan Institute, 2017). One study led by Jennifer Eberhardt, PhD, professor of psychology at Stanford University, reviewed body camera footage and found that police officers in Oakland, California, treated Black people with less respect than whites (Voigt, R., et al., PNAS, Vol. 114, No. 25, 2017).

Eberhardt and others, including Lorie Fridell, PhD, a professor of criminology at the University of South Florida, have designed and begun to deliver training programs on implicit bias to law enforcement agencies around the country (“Producing Bias-Free Policing: A Science-Based Approach,” Springer Publishing, 2017).

Those programs, which typically mix instruction, discussion and role-playing, aim to help agencies reduce high-discretion policing and hold officers accountable for biased practices. But there’s no standardized curriculum—and experts say more research is needed to determine whether implicit bias training has a lasting impact and how such training can work alongside other agency reform efforts.

“There seem to be some forms of training that are effective, but the studies on these interventions are still pretty limited,” says Lai. “We just don’t know that much one way or the other.”

The power of peer intervention

Another intervention that has shown promise for reducing violence among police is known as Project ABLE, or Active Bystandership for Law Enforcement. Based on the work of psychologist Ervin Staub, PhD, an emeritus professor at the University of Massachusetts Amherst and past president of APA’s Div. 48 (Society for the Study of Peace, Conflict and Violence), the program promotes a culture of peer intervention. It teaches officers to prevent their peers from perpetrating unnecessary violence, which can save both lives and careers. Developed by the New Orleans Police Department in 2014 and originally named Ethical Policing Is Courageous (EPIC), Project ABLE is now being adopted by all police departments in New Hampshire and Washington state, as well as those in Baltimore, Boston, Philadelphia, several other cities and the FBI National Academy.

When an officer commits an act of unnecessary violence, his colleagues face a tough choice, Dvoskin says. Report the act and get a reputation as a “rat”—which may mean your next call for backup goes unanswered—or lie, which is a crime.

“What if, instead, you can prevent the bad thing from happening in the first place?” he says. “What if you manifested your loyalty to a fellow officer by helping him or her stay out of trouble?”

Staub says minor interventions can be highly effective. During recent protests of confederate monuments in New Orleans, an officer stopped a peer from attacking demonstrators by putting an arm around his shoulder. Trainees also apply strategies taught by the program to themselves. One officer in New Orleans reported using EPIC to avoid retaliating against a protester who had spit in her face.

That sort of behavior requires culture change. Police officers need to get comfortable both giving and receiving such interventions—and that culture must be modeled and supported by the highest levels of leadership within an organization, Dvoskin says.

To test his model of active bystandership, Staub studied examples of group violence, such as genocide, observing how hostility and violence evolve progressively. He has also conducted experimental research to understand how people respond to emergencies depending on the actions of those around them. In one study, participants’ helping behavior in response to a simulated emergency ranged from 25% to 100% of the time depending on a confederate’s response to the emergency. He also found that those who are asked to help once are more likely to volunteer later (Staub, E., “The Roots of Goodness and Resistance to Evil,” Oxford University Press, 2015).

Now, Project ABLE has support from Georgetown University and the international law firm Sheppard Mullin, which will help fund free training in active bystandership for any interested U.S. police department—and they’ve had hundreds of inquiries since June. Dvoskin, Staub and their team are now working to standardize lesson plans and policy guidelines.

“If this training is introduced in many police departments and done effectively, I believe that policing in America will be transformed,” Staub says.

Understanding and changing officer behavior

Psychologists are also helping agencies collect, report and understand data on their officers’ behavior—data that can point to further policy changes to reduce unnecessary violence and racial bias.

Simply changing the definition of a “police stop,” for instance, can help identify patterns of racial profiling that might otherwise be missed, says social psychologist Jack Glaser, PhD, a professor at the University of California, Berkeley’s Goldman School of Public Policy. Glaser has advised the California attorney general’s office on how to collect policing data, including revising the regulations on police stop reporting.

“Some police-civilian encounters are very casual and are not typically recognized as stops—but they are done with investigatory intent and can escalate to a detention,” he says.

For example, a pedestrian might voluntarily speak with a police officer who says, “Hi, can I ask you a question?”—but that conversation could lead to a search and even an arrest. Those stops typically aren’t reported, so racial bias in such practices could go unchecked.

Glaser has also partnered with CPE for a nationwide effort to aggregate data on police behavior with the National Justice Database, which draws from nearly 100 police departments representing more than a third of the U.S. population. He has worked to standardize and harmonize that data—which includes hundreds of thousands of entries on police stops, searches and use of force and can vary a lot from one agency to the next—so that researchers can start making comparisons and looking for larger trends.

Glaser says reporting officer behavioral data in different ways can paint a very different picture about whether racial disparities exist—so it’s important to get it right. For example, some departments consider officer presence or unholstering a weapon instances of police use of force, while others do not.

Goff, Glaser and their team delved into police use of force data to explore why some researchers, such as economist Roland Fryer, PhD, of Harvard University, have reported no racial differences in officer-involved shootings (Fryer, R.G., Journal of Political Economy, Vol. 127, No. 3, 2019). Their preliminary analysis shows that racial disparities may not exist in all officer-involved shootings, but that there’s a clear bias against African Americans when the victim is unarmed.

“Given that the protest movement is overwhelmingly about unarmed people getting killed by police, that seems to be the most important data point—but it seems to be getting lost,” Glaser says.

One major takeaway from the National Justice Database so far is that police are more likely to display racial bias when they conduct a “high-discretion search”—usually done on a hunch in ambiguous circumstances—versus a “low-discretion search,” a more routine activity, for instance when a person has already been detained for a crime. When the California Highway Patrol banned high-discretion searches, racial disparities began to level off (Racial & Identity Profiling Advisory Board Annual Report, 2020).

“The obvious implication there is to try and minimize high-discretion searches,” Glaser says. “The tremendous amount of discretion given to police promotes decision-making under ambiguity and uncertainty, which psychologists know is ripe for stereotype influence.”

Screening officer candidates

Other psychologists have worked to adapt the police selection process to address the issue of implicit bias. Portland-based forensic psychologist David Corey, PhD, ABPP, has urged departments to add “cultural competence” as a criterion for screening law enforcement officers. “On the surface, the implicit bias literature is dismally depressing, because it tells us that everybody has automatic stereotypes that operate unconsciously and affect behavior,” says Corey, who also founded the American Board of Police and Public Safety Psychology.

Because of measurement issues, it’s not practical to screen candidates for policing jobs based on their implicit biases. But studies show that some personality dimensions can help officers temper those biases (Ben-Porath, Y.S., “Interpreting the MMPI-2-RF,” University of Minnesota Press, 2012). Specifically, people high in executive functioning, emotional regulation skills and metacognitive abilities are better able to prevent implicit biases from affecting their behavior. A capacity for theory of mind formation—the ability to anticipate how others will behave based on their actions or tone of voice—also helps officers learn to bypass their initial instincts.

“Those competencies render implicit bias more malleable,” says Corey. “So, my focus, and that of a growing number of colleagues around the country, is to evaluate applicants for those qualities.”

The Portland Police Bureau, as well as several other agencies in the Pacific Northwest, have added such measures to their selection battery.

Answering more questions

Looking ahead, psychologists are working to address gaps in the data in crucial areas such as use of force, says Shauna Laughna, PhD, ABPP, a Florida-based police and public safety psychologist and chair of APA Div. 18’s Police and Public Safety section. She adds that recruitment, training, discipline and retention of personnel can vary greatly across the 18,000 law enforcement agencies in the United States. That points to a need for more data, standardized measures—for instance, what constitutes excessive use of force—and a comprehensive national database on policing incidents.

“Attempting to generalize from data gathered at one agency to another may not always be prudent,” she says.

As reform efforts continue at the local and state levels, there’s one other essential thing the field can do, says Colby Mills, PhD, a clinical psychologist who works with the Fairfax County Police Department in Virginia: Provide more formal training opportunities for police psychologists, including during graduate school and in the form of continuing education. The limited police psychology coursework currently available within forensic psychology programs often does not include adequate training on the culture, ethics and special skills required to do such work, he says.

“It takes a lot of courage for a police officer to reach out to a mental health professional, because of the stigmas and the pressures they experience,” Mills says. “But once they do it, we owe it to them to provide a qualified professional who knows what they face and understands their culture.”

Critical incident response

In addition to their involvement with department-wide training efforts, psychologists are also increasingly providing ongoing mental health services, for instance after an officer-involved shooting occurs, says Colby Mills, PhD, a clinical psychologist who contracts with the Fairfax County Police Department in Virginia.

Along with peer support officers and the station’s police chaplain, Mills deploys immediately after a critical incident occurs and delivers Stress First Aid, a model developed for the military that can support officers in processing emotions (Stress First Aid for Law Enforcement, National Center for Posttraumatic Stress Disorder, 2016).

“We want to strike a balance where we offer support without implying that an officer will automatically need help to recover,” Mills says.

The Fairfax County Police Department works with about a dozen psychologists who provide critical incident response, therapy, psychoeducation, consultations and pre-employment screenings.

“In general, police and public safety agencies are starting to embrace these sorts of psychological services more and more,” Mills says.

Further reading

A Meta-Analysis of Procedures to Change Implicit Measures
Forscher, P.S., et al. Journal of Personality and Social Psychology, 2019

The Science of Justice: Race, Arrests and Police Use of Force
Goff, P.A., et al. Center for Policing Equity, 2016

Preventing Violence and Promoting Active Bystandership and Peace: My Life in Research and Applications
Staub, E., Peace and Conflict: Journal of Peace Psychology, 2018

, which has been documented across a range of domains and populations (State of the Science: Implicit Bias Review, Kirwan Institute, 2017). One study led by Jennifer Eberhardt, PhD, professor of psychology at Stanford University, reviewed body camera footage and found that police officers in Oakland, California, treated Black people with less respect than whites (Voigt, R., et al., PNAS, Vol. 114, No. 25, 2017).

Eberhardt and others, including Lorie Fridell, PhD, a professor of criminology at the University of South Florida, have designed and begun to deliver training programs on implicit bias to law enforcement agencies around the country (“Producing Bias-Free Policing: A Science-Based Approach,” Springer Publishing, 2017).

Those programs, which typically mix instruction, discussion and role-playing, aim to help agencies reduce high-discretion policing and hold officers accountable for biased practices. But there’s no standardized curriculum—and experts say more research is needed to determine whether implicit bias training has a lasting impact and how such training can work alongside other agency reform efforts.

“There seem to be some forms of training that are effective, but the studies on these interventions are still pretty limited,” says Lai. “We just don’t know that much one way or the other.”

The power of peer intervention

Another intervention that has shown promise for reducing violence among police is known as Project ABLE, or Active Bystandership for Law Enforcement. Based on the work of psychologist Ervin Staub, PhD, an emeritus professor at the University of Massachusetts Amherst and past president of APA’s Div. 48 (Society for the Study of Peace, Conflict and Violence), the program promotes a culture of peer intervention. It teaches officers to prevent their peers from perpetrating unnecessary violence, which can save both lives and careers. Developed by the New Orleans Police Department in 2014 and originally named Ethical Policing Is Courageous (EPIC), Project ABLE is now being adopted by all police departments in New Hampshire and Washington state, as well as those in Baltimore, Boston, Philadelphia, several other cities and the FBI National Academy.

When an officer commits an act of unnecessary violence, his colleagues face a tough choice, Dvoskin says. Report the act and get a reputation as a “rat”—which may mean your next call for backup goes unanswered—or lie, which is a crime.

“What if, instead, you can prevent the bad thing from happening in the first place?” he says. “What if you manifested your loyalty to a fellow officer by helping him or her stay out of trouble?”

Staub says minor interventions can be highly effective. During recent protests of confederate monuments in New Orleans, an officer stopped a peer from attacking demonstrators by putting an arm around his shoulder. Trainees also apply strategies taught by the program to themselves. One officer in New Orleans reported using EPIC to avoid retaliating against a protester who had spit in her face.

That sort of behavior requires culture change. Police officers need to get comfortable both giving and receiving such interventions—and that culture must be modeled and supported by the highest levels of leadership within an organization, Dvoskin says.

To test his model of active bystandership, Staub studied examples of group violence, such as genocide, observing how hostility and violence evolve progressively. He has also conducted experimental research to understand how people respond to emergencies depending on the actions of those around them. In one study, participants’ helping behavior in response to a simulated emergency ranged from 25% to 100% of the time depending on a confederate’s response to the emergency. He also found that those who are asked to help once are more likely to volunteer later (Staub, E., “The Roots of Goodness and Resistance to Evil,” Oxford University Press, 2015).

Now, Project ABLE has support from Georgetown University and the international law firm Sheppard Mullin, which will help fund free training in active bystandership for any interested U.S. police department—and they’ve had hundreds of inquiries since June. Dvoskin, Staub and their team are now working to standardize lesson plans and policy guidelines.

“If this training is introduced in many police departments and done effectively, I believe that policing in America will be transformed,” Staub says.

Understanding and changing officer behavior

Psychologists are also helping agencies collect, report and understand data on their officers’ behavior—data that can point to further policy changes to reduce unnecessary violence and racial bias.

Simply changing the definition of a “police stop,” for instance, can help identify patterns of racial profiling that might otherwise be missed, says social psychologist Jack Glaser, PhD, a professor at the University of California, Berkeley’s Goldman School of Public Policy. Glaser has advised the California attorney general’s office on how to collect policing data, including revising the regulations on police stop reporting.

“Some police-civilian encounters are very casual and are not typically recognized as stops—but they are done with investigatory intent and can escalate to a detention,” he says.

For example, a pedestrian might voluntarily speak with a police officer who says, “Hi, can I ask you a question?”—but that conversation could lead to a search and even an arrest. Those stops typically aren’t reported, so racial bias in such practices could go unchecked.

Glaser has also partnered with CPE for a nationwide effort to aggregate data on police behavior with the National Justice Database, which draws from nearly 100 police departments representing more than a third of the U.S. population. He has worked to standardize and harmonize that data—which includes hundreds of thousands of entries on police stops, searches and use of force and can vary a lot from one agency to the next—so that researchers can start making comparisons and looking for larger trends.

Glaser says reporting officer behavioral data in different ways can paint a very different picture about whether racial disparities exist—so it’s important to get it right. For example, some departments consider officer presence or unholstering a weapon instances of police use of force, while others do not.

Goff, Glaser and their team delved into police use of force data to explore why some researchers, such as economist Roland Fryer, PhD, of Harvard University, have reported no racial differences in officer-involved shootings (Fryer, R.G., Journal of Political Economy, Vol. 127, No. 3, 2019). Their preliminary analysis shows that racial disparities may not exist in all officer-involved shootings, but that there’s a clear bias against African Americans when the victim is unarmed.

“Given that the protest movement is overwhelmingly about unarmed people getting killed by police, that seems to be the most important data point—but it seems to be getting lost,” Glaser says.

One major takeaway from the National Justice Database so far is that police are more likely to display racial bias when they conduct a “high-discretion search”—usually done on a hunch in ambiguous circumstances—versus a “low-discretion search,” a more routine activity, for instance when a person has already been detained for a crime. When the California Highway Patrol banned high-discretion searches, racial disparities began to level off (Racial & Identity Profiling Advisory Board Annual Report, 2020).

“The obvious implication there is to try and minimize high-discretion searches,” Glaser says. “The tremendous amount of discretion given to police promotes decision-making under ambiguity and uncertainty, which psychologists know is ripe for stereotype influence.”

Screening officer candidates

Other psychologists have worked to adapt the police selection process to address the issue of implicit bias. Portland-based forensic psychologist David Corey, PhD, ABPP, has urged departments to add “cultural competence” as a criterion for screening law enforcement officers. “On the surface, the implicit bias literature is dismally depressing, because it tells us that everybody has automatic stereotypes that operate unconsciously and affect behavior,” says Corey, who also founded the American Board of Police and Public Safety Psychology.

Because of measurement issues, it’s not practical to screen candidates for policing jobs based on their implicit biases. But studies show that some personality dimensions can help officers temper those biases (Ben-Porath, Y.S., “Interpreting the MMPI-2-RF,” University of Minnesota Press, 2012). Specifically, people high in executive functioning, emotional regulation skills and metacognitive abilities are better able to prevent implicit biases from affecting their behavior. A capacity for theory of mind formation—the ability to anticipate how others will behave based on their actions or tone of voice—also helps officers learn to bypass their initial instincts.

“Those competencies render implicit bias more malleable,” says Corey. “So, my focus, and that of a growing number of colleagues around the country, is to evaluate applicants for those qualities.”

The Portland Police Bureau, as well as several other agencies in the Pacific Northwest, have added such measures to their selection battery.

Answering more questions

Looking ahead, psychologists are working to address gaps in the data in crucial areas such as use of force, says Shauna Laughna, PhD, ABPP, a Florida-based police and public safety psychologist and chair of APA Div. 18’s Police and Public Safety section. She adds that recruitment, training, discipline and retention of personnel can vary greatly across the 18,000 law enforcement agencies in the United States. That points to a need for more data, standardized measures—for instance, what constitutes excessive use of force—and a comprehensive national database on policing incidents.

“Attempting to generalize from data gathered at one agency to another may not always be prudent,” she says.

As reform efforts continue at the local and state levels, there’s one other essential thing the field can do, says Colby Mills, PhD, a clinical psychologist who works with the Fairfax County Police Department in Virginia: Provide more formal training opportunities for police psychologists, including during graduate school and in the form of continuing education. The limited police psychology coursework currently available within forensic psychology programs often does not include adequate training on the culture, ethics and special skills required to do such work, he says.

“It takes a lot of courage for a police officer to reach out to a mental health professional, because of the stigmas and the pressures they experience,” Mills says. “But once they do it, we owe it to them to provide a qualified professional who knows what they face and understands their culture.”

Critical incident response

In addition to their involvement with department-wide training efforts, psychologists are also increasingly providing ongoing mental health services, for instance after an officer-involved shooting occurs, says Colby Mills, PhD, a clinical psychologist who contracts with the Fairfax County Police Department in Virginia.

Along with peer support officers and the station’s police chaplain, Mills deploys immediately after a critical incident occurs and delivers Stress First Aid, a model developed for the military that can support officers in processing emotions (Stress First Aid for Law Enforcement, National Center for Posttraumatic Stress Disorder, 2016).

“We want to strike a balance where we offer support without implying that an officer will automatically need help to recover,” Mills says.

The Fairfax County Police Department works with about a dozen psychologists who provide critical incident response, therapy, psychoeducation, consultations and pre-employment screenings.

“In general, police and public safety agencies are starting to embrace these sorts of psychological services more and more,” Mills says.

Further reading

A Meta-Analysis of Procedures to Change Implicit Measures
Forscher, P.S., et al. Journal of Personality and Social Psychology, 2019

The Science of Justice: Race, Arrests and Police Use of Force
Goff, P.A., et al. Center for Policing Equity, 2016

Preventing Violence and Promoting Active Bystandership and Peace: My Life in Research and Applications
Staub, E., Peace and Conflict: Journal of Peace Psychology, 2018

What works to reduce police brutality

Psychologists’ research is pinpointing the factors that lead to overly aggressive, biased policing—and intervention that can prevent it

police in riot gear

When the Las Vegas Police Department applied a psychology-informed “hands off” policy for officers involved in foot chases, use of force dropped by 23%. In Seattle, officers trained in a “procedural justice” intervention designed in part by psychologists used force up to 40% less. These are just a few examples of the work the field is doing to address police brutality.

“There’s much more openness to the idea of concrete change among police departments,” says Joel Dvoskin, PhD, ABPP, a clinical and forensic psychologist and past president of APA’s Div. 18 (Psychologists in Public Service).

That shift is backed by support from the public. Since 2016, the share of Americans who say that police use the right amount of force, treat racial and ethnic groups equally and hold officers accountable for misconduct has declined substantially, according to the Pew Research Center (Majority of Public Favors Giving Civilians the Power to Sue Officers for Misconduct, 2020).

Psychologists have already played a critical role in the reform process—from collecting data on biased police stops, searches and use of force to designing and delivering interventions that reduce the chances that police will rely on stereotypes, for instance by limiting the amount of discretion officers have during searches.

Now, psychologists are promoting those interventions to more police departments, conducting research to determine how well they work and continuing to collect and organize data on police behavior and department culture.

Criminal justice—police, courts, prisons—has been called an evidence-free zone,” says Tom Tyler, PhD, a professor of psychology at Yale Law School and an expert in the psychology of justice. “People in positions of power tend to make policy decisions based on intuition and common sense—presumptions that we as psychologists recognize are often in error.”

“What’s really needed is an evidence-informed model of criminal justice,” he says. “And a lot of that evidence can come from psychologists.”

Psychological research in action

In 2015, President Obama’s Task Force on 21st Century Policing reviewed scientific data on policing, recommending major policy changes at the federal level to improve oversight, training, officer wellness and more (Final Report of the President’s Task Force on 21st Century Policing, 2015).

Federal efforts have slowed in recent years, with most changes happening at the local level. But with around 18,000 police departments nationwide, that response has been fragmented and inconsistent (National Sources of Law Enforcement Employment Data, Bureau of Justice Statistics, 2016).

Still, psychologists have forged ahead with efforts that are making a difference. One key contribution involves spurring policy changes and interventions based on psychological insights.

“One of the most influential approaches coming from psychology is training in procedurally just policing,” says Calvin Lai, PhD, an assistant professor of psychological and brain sciences at Washington University in St. Louis.

That approach aims to increase the public’s trust in police by drawing on psychological research on justice and fairness. It involves teaching officers strategies such as explaining to citizens why they’ve been stopped and how it will benefit public safety (Principles of Procedurally Just Policing, The Justice Collaboratory at Yale Law School, 2018).

“We know that the policing model of using force to compel compliance lowers the crime rate but does not build trust,” says Tyler, who has developed and studied models of procedurally just policing. “The crime rate has declined about 75% in the last 30 years, but public trust in the police hasn’t increased at all.”

His research has shown that what community members really want is for police to treat them with respect and to give them a voice—a chance to explain their situation before action is taken. People also want to know that police are sincere, care about the well-being of their community, and act in an unbiased and consistent way—for example, by explaining the rules they use and how they’re applying them.

A study in Seattle randomly assigned officers to receive training in procedurally just policing, leading to a reduction in use of force of between 15% and 40%, depending on the situation (Owens, E., et al., Criminology & Public Policy, Vol. 17, No. 1, 2018).

“It seems to be doing what we’d hope in terms of promoting better relationships between police officers and community members,” says Lai.

The Center for Policing Equity (CPE), led by psychologist Phillip Atiba Goff, PhD, of Yale University, has also led a number of psychology-driven policy changes in police departments around the country. In an effort to cut down on high-adrenaline encounters—where police officers are more likely to rely on stereotypes—Goff urged the Las Vegas Police Department to bar officers involved in a foot pursuit from handling suspects when the chase ends. The policy led to a 23% drop in use of force at the department, an 11% reduction in officer injury and a simultaneous drop in racial disparities in use of force data. CPE has also pioneered efforts to recruit racially and ethnically diverse officer candidates and to make immigration enforcement more consistent.

Another key area that psychological interventions target is implicit bias, which has been documented across a range of domains and populations (State of the Science: Implicit Bias Review, Kirwan Institute, 2017). One study led by Jennifer Eberhardt, PhD, professor of psychology at Stanford University, reviewed body camera footage and found that police officers in Oakland, California, treated Black people with less respect than whites (Voigt, R., et al., PNAS, Vol. 114, No. 25, 2017).

Eberhardt and others, including Lorie Fridell, PhD, a professor of criminology at the University of South Florida, have designed and begun to deliver training programs on implicit bias to law enforcement agencies around the country (“Producing Bias-Free Policing: A Science-Based Approach,” Springer Publishing, 2017).

Those programs, which typically mix instruction, discussion and role-playing, aim to help agencies reduce high-discretion policing and hold officers accountable for biased practices. But there’s no standardized curriculum—and experts say more research is needed to determine whether implicit bias training has a lasting impact and how such training can work alongside other agency reform efforts.

“There seem to be some forms of training that are effective, but the studies on these interventions are still pretty limited,” says Lai. “We just don’t know that much one way or the other.”

The power of peer intervention

Another intervention that has shown promise for reducing violence among police is known as Project ABLE, or Active Bystandership for Law Enforcement. Based on the work of psychologist Ervin Staub, PhD, an emeritus professor at the University of Massachusetts Amherst and past president of APA’s Div. 48 (Society for the Study of Peace, Conflict and Violence), the program promotes a culture of peer intervention. It teaches officers to prevent their peers from perpetrating unnecessary violence, which can save both lives and careers. Developed by the New Orleans Police Department in 2014 and originally named Ethical Policing Is Courageous (EPIC), Project ABLE is now being adopted by all police departments in New Hampshire and Washington state, as well as those in Baltimore, Boston, Philadelphia, several other cities and the FBI National Academy.

When an officer commits an act of unnecessary violence, his colleagues face a tough choice, Dvoskin says. Report the act and get a reputation as a “rat”—which may mean your next call for backup goes unanswered—or lie, which is a crime.

“What if, instead, you can prevent the bad thing from happening in the first place?” he says. “What if you manifested your loyalty to a fellow officer by helping him or her stay out of trouble?”

Staub says minor interventions can be highly effective. During recent protests of confederate monuments in New Orleans, an officer stopped a peer from attacking demonstrators by putting an arm around his shoulder. Trainees also apply strategies taught by the program to themselves. One officer in New Orleans reported using EPIC to avoid retaliating against a protester who had spit in her face.

That sort of behavior requires culture change. Police officers need to get comfortable both giving and receiving such interventions—and that culture must be modeled and supported by the highest levels of leadership within an organization, Dvoskin says.

To test his model of active bystandership, Staub studied examples of group violence, such as genocide, observing how hostility and violence evolve progressively. He has also conducted experimental research to understand how people respond to emergencies depending on the actions of those around them. In one study, participants’ helping behavior in response to a simulated emergency ranged from 25% to 100% of the time depending on a confederate’s response to the emergency. He also found that those who are asked to help once are more likely to volunteer later (Staub, E., “The Roots of Goodness and Resistance to Evil,” Oxford University Press, 2015).

Now, Project ABLE has support from Georgetown University and the international law firm Sheppard Mullin, which will help fund free training in active bystandership for any interested U.S. police department—and they’ve had hundreds of inquiries since June. Dvoskin, Staub and their team are now working to standardize lesson plans and policy guidelines.

“If this training is introduced in many police departments and done effectively, I believe that policing in America will be transformed,” Staub says.

Understanding and changing officer behavior

Psychologists are also helping agencies collect, report and understand data on their officers’ behavior—data that can point to further policy changes to reduce unnecessary violence and racial bias.

Simply changing the definition of a “police stop,” for instance, can help identify patterns of racial profiling that might otherwise be missed, says social psychologist Jack Glaser, PhD, a professor at the University of California, Berkeley’s Goldman School of Public Policy. Glaser has advised the California attorney general’s office on how to collect policing data, including revising the regulations on police stop reporting.

“Some police-civilian encounters are very casual and are not typically recognized as stops—but they are done with investigatory intent and can escalate to a detention,” he says.

For example, a pedestrian might voluntarily speak with a police officer who says, “Hi, can I ask you a question?”—but that conversation could lead to a search and even an arrest. Those stops typically aren’t reported, so racial bias in such practices could go unchecked.

Glaser has also partnered with CPE for a nationwide effort to aggregate data on police behavior with the National Justice Database, which draws from nearly 100 police departments representing more than a third of the U.S. population. He has worked to standardize and harmonize that data—which includes hundreds of thousands of entries on police stops, searches and use of force and can vary a lot from one agency to the next—so that researchers can start making comparisons and looking for larger trends.

Glaser says reporting officer behavioral data in different ways can paint a very different picture about whether racial disparities exist—so it’s important to get it right. For example, some departments consider officer presence or unholstering a weapon instances of police use of force, while others do not.

Goff, Glaser and their team delved into police use of force data to explore why some researchers, such as economist Roland Fryer, PhD, of Harvard University, have reported no racial differences in officer-involved shootings (Fryer, R.G., Journal of Political Economy, Vol. 127, No. 3, 2019). Their preliminary analysis shows that racial disparities may not exist in all officer-involved shootings, but that there’s a clear bias against African Americans when the victim is unarmed.

“Given that the protest movement is overwhelmingly about unarmed people getting killed by police, that seems to be the most important data point—but it seems to be getting lost,” Glaser says.

One major takeaway from the National Justice Database so far is that police are more likely to display racial bias when they conduct a “high-discretion search”—usually done on a hunch in ambiguous circumstances—versus a “low-discretion search,” a more routine activity, for instance when a person has already been detained for a crime. When the California Highway Patrol banned high-discretion searches, racial disparities began to level off (Racial & Identity Profiling Advisory Board Annual Report, 2020).

“The obvious implication there is to try and minimize high-discretion searches,” Glaser says. “The tremendous amount of discretion given to police promotes decision-making under ambiguity and uncertainty, which psychologists know is ripe for stereotype influence.”

Screening officer candidates

Other psychologists have worked to adapt the police selection process to address the issue of implicit bias. Portland-based forensic psychologist David Corey, PhD, ABPP, has urged departments to add “cultural competence” as a criterion for screening law enforcement officers. “On the surface, the implicit bias literature is dismally depressing, because it tells us that everybody has automatic stereotypes that operate unconsciously and affect behavior,” says Corey, who also founded the American Board of Police and Public Safety Psychology.

Because of measurement issues, it’s not practical to screen candidates for policing jobs based on their implicit biases. But studies show that some personality dimensions can help officers temper those biases (Ben-Porath, Y.S., “Interpreting the MMPI-2-RF,” University of Minnesota Press, 2012). Specifically, people high in executive functioning, emotional regulation skills and metacognitive abilities are better able to prevent implicit biases from affecting their behavior. A capacity for theory of mind formation—the ability to anticipate how others will behave based on their actions or tone of voice—also helps officers learn to bypass their initial instincts.

“Those competencies render implicit bias more malleable,” says Corey. “So, my focus, and that of a growing number of colleagues around the country, is to evaluate applicants for those qualities.”

The Portland Police Bureau, as well as several other agencies in the Pacific Northwest, have added such measures to their selection battery.

Answering more questions

Looking ahead, psychologists are working to address gaps in the data in crucial areas such as use of force, says Shauna Laughna, PhD, ABPP, a Florida-based police and public safety psychologist and chair of APA Div. 18’s Police and Public Safety section. She adds that recruitment, training, discipline and retention of personnel can vary greatly across the 18,000 law enforcement agencies in the United States. That points to a need for more data, standardized measures—for instance, what constitutes excessive use of force—and a comprehensive national database on policing incidents.

“Attempting to generalize from data gathered at one agency to another may not always be prudent,” she says.

As reform efforts continue at the local and state levels, there’s one other essential thing the field can do, says Colby Mills, PhD, a clinical psychologist who works with the Fairfax County Police Department in Virginia: Provide more formal training opportunities for police psychologists, including during graduate school and in the form of continuing education. The limited police psychology coursework currently available within forensic psychology programs often does not include adequate training on the culture, ethics and special skills required to do such work, he says.

“It takes a lot of courage for a police officer to reach out to a mental health professional, because of the stigmas and the pressures they experience,” Mills says. “But once they do it, we owe it to them to provide a qualified professional who knows what they face and understands their culture.”

Critical incident response

In addition to their involvement with department-wide training efforts, psychologists are also increasingly providing ongoing mental health services, for instance after an officer-involved shooting occurs, says Colby Mills, PhD, a clinical psychologist who contracts with the Fairfax County Police Department in Virginia.

Along with peer support officers and the station’s police chaplain, Mills deploys immediately after a critical incident occurs and delivers Stress First Aid, a model developed for the military that can support officers in processing emotions (Stress First Aid for Law Enforcement, National Center for Posttraumatic Stress Disorder, 2016).

“We want to strike a balance where we offer support without implying that an officer will automatically need help to recover,” Mills says.

The Fairfax County Police Department works with about a dozen psychologists who provide critical incident response, therapy, psychoeducation, consultations and pre-employment screenings.

“In general, police and public safety agencies are starting to embrace these sorts of psychological services more and more,” Mills says.

Further reading

A Meta-Analysis of Procedures to Change Implicit Measures
Forscher, P.S., et al. Journal of Personality and Social Psychology, 2019

The Science of Justice: Race, Arrests and Police Use of Force
Goff, P.A., et al. Center for Policing Equity, 2016

Preventing Violence and Promoting Active Bystandership and Peace: My Life in Research and Applications
Staub, E., Peace and Conflict: Journal of Peace Psychology, 2018