By Jack Glaser

It is a time of protests: Occupy, student fees, police killings. Are they all connected? Yes and no. They share the theme that disenfranchisement of frustrated populations with little political power has reached a tipping point. The protest movements may inspire each other but, if we lump them together, we may fail to learn the lesson of this moment and move forward. The continued protests in cities around the country, including Oakland and Berkeley, over police killings of unarmed black men represent a movement unto itself. The movement’s message is very clear, and it is being broadcast on T-shirts and banners: Black Lives Matter. The message seems so obvious, and so part of the anguish stems from the fact that it even needs to be said.

Tragic and jarring as they may be, the shootings (or, in the case of Eric Garner, a fatal choke hold) are only the tip of the iceberg. Racial profiling and excessive police force used against blacks are very real phenomena, and they have collateral effects that cause black communities to lose income, human and social capital, electoral representation, sense of belonging, and, yes, life. The protesters are telling us that these terrible problems need to be dealt with.

The problems will not be solved, however, by blaming the police.

Just as the protests do, research on race and criminal justice sends a clear message: Black people are treated as though their lives matter less. They are subjected to policing at a rate that is unjustified by their behavior. All else being equal, they are more likely to be stopped, searched, have force used against them, get arrested, charged, convicted and be given harsher penalties (longer sentences). This is born out in real-world data across many studies, and it is born out in carefully designed experiments.

Certainly, police officers should be held to account for discriminatory policing and excessive use of force. But most Americans (including many black Americans) have in their heads the stereotypes and feelings that cause them to regard black people differently. Consequently, there is in many important realms, including employment, lending, health care, etc. With policing, however, the discriminatory outcomes are immediately consequential, often dire — even fatal. Combine the stereotypes, the import of law enforcement decisions, and the permissiveness of our legal system when it comes to police discretion in stops, searches and use of force, and you have a recipe for disaster.

The stereotypes will be hard to change, and the catch-22 is that they are fueled in part by the very biased policing practices that are used to justify them. Disproportionate policing of minorities causes disproportionate incarceration and marginalization of minorities, which in turn distorts perceptions of them. The law will also be hard to change — the U.S. Supreme Court has shown indifference to the actual motivations an officer has for making a stop, as long as there is a valid pretext. The Department of Justice supervises only federal policing, and Congress has demonstrated itself to be incapable of even voting on the oft-introduced End Racial Profiling Act.

State and local governments, including police commissions and chiefs, however, have considerable latitude to reform policing practices. In some cases, they are doing just that, as with Richmond’s dramatic reduction in police shootings resulting from new training and policies. Law enforcement agencies that have cut back their rates of stops and searches have increased police effectiveness and intruded on fewer people’s lives, while reducing racial and ethnic disparities. These are reforms that the public can and should demand of their police.

First, however, we must break the cycle of mass incarceration of black men by reducing the discretion that police have in deciding who to investigate. Telling people what not to do is of limited value if you do not give them a good substitute, so reducing discretion will require prescriptive training on who should be investigated — offering valid, evidence-based criteria for judgments of criminally suspicious behavior. Departments need the resources, including more officers, to engage meaningfully in “community oriented policing” practices that serve to promote positive interactions between police and civilians and break down the stereotypes and distrust. All of these efforts must be tracked through more thorough and reliable data collection on police stops and use of force; and these data will, in turn, promote better supervision and accountability of officers.

Black Americans are not imagining the problem of biased policing. It is real. It is measurable. It is even, from the perspective of psychological science, not surprising. And it is devastating. It is not, however, irremediable.

Jack Glaser is a professor and associate dean at the Goldman School of Public Policy at UC Berkeley. He is the author of Suspect Race: Causes and Consequences of Racial Profiling, (Oxford University Press, December 2014).

This article first appeared in the San Francisco Gate.