The city of Baltimore was rocked by protests and riots over the death of Freddie Gray, a 25-year-old African American man who died in police custody. Tragically, Gray’s death was only one of a recent in a series of racially-charged, often violent, incidents. On April 4th, Walter Scott was fatally shot by a police officer after fleeing from a routine traffic stop. On March 8th, Sigma Alpha Epsilon fraternity members were caught on camera gleefully chanting, “There Will Never Be A N***** In SAE.” On March 1st, a homeless Black man was shot in broad daylight by a Los Angeles police officer. And these are not isolated incidents, of course. Institutional and systemic racism reinforce discrimination in countless situations, including hiring, sentencing, housing, and even mortgage lending.

It would be easy to see in all this powerful evidence that racism is a permanent fixture in America’s social fabric and even, perhaps, an inevitable aspect of human nature. Indeed, the mere act of labeling others according to their age, gender, or race is a reflexive habit of the human mind. Social categories, like race, impact our thinking quickly, often outside of our awareness. Extensive research has found that these implicit racial biases—negative thoughts and feelings about people from other races—are automatic, pervasive, and difficult to suppress. Neuroscientists have also explored racial prejudice by exposing people to images of faces while scanning their brains in fMRI machines. Early studies found that when people viewed faces of another race, the amount of activity in the amygdala—a small brain structure associated with experiencing emotions, including fear—was associated with individual differences on implicit measures of racial bias. This work has led many to conclude that racial biases might be part of a primitive—and possibly hard-wired—neural fear response to racial out-groups.

There is little question that categories such as race, gender, and age play a major role in shaping the biases and stereotypes that people bring to bear in their judgments of others. However, research has shown that how people categorize themselves may be just as fundamental to understanding prejudice as how they categorize others. When people categorize themselves as part of a group, their self-concept shifts from the individual (“I”) to the collective level (“us”). People form groups rapidly and favor members of their own group even when groups are formed on arbitrary grounds, such as the simple flip of a coin. These findings highlight the remarkable ease with which humans form coalitions.

Recent research confirms that coalition-based preferences trump race-based preferences. For example, both Democrats and Republicans favor the resumes of those affiliated with their political party much more than they favor those who share their race. These coalition-based preferences remain powerful even in the absence of the animosity present in electoral politics. Our research has shown that the simple act of placing people on a mixed-race team can diminish their automatic racial bias. In a series of experiments, White participants who were randomly placed on a mixed-race team—the Tigers or Lions—showed little evidence of implicit racial bias. Merely belonging to a mixed-race team trigged positive automatic associations with all of the members of their own group, irrespective of race. Being a part of one of these seemingly trivial mixed-race groups produced similar effects on brain activity—the amygdala responded to team membership rather than race. Taken together, these studies indicate that momentary changes in group membership can override the influence of race on the way we see, think about, and feel toward people who are different from ourselves.

Although these coalition-based distinctions might be the most basic building block of bias, they say little about the other factors that cause group conflict. Why do some groups get ignored while others get attacked? Whenever we encounter a new person or group we are motivated to answer two questions as quickly as possible: “is this person a friend or foe?” and “are they capable of enacting their intentions toward me?” In other words, once we have determined that someone is a member of an out-group, we need to determine what kind? The nature of the relations between groups—are we cooperative, competitive, or neither?—and their relative status—do you have access to resources?—largely determine the course of intergroup interactions.

Groups that are seen as competitive with one’s interests, and capable of enacting their nasty intentions, are much more likely to be targets of hostility than more benevolent (e.g., elderly) or powerless (e.g., homeless) groups. This is one reason why sports rivalries have such psychological potency. For instance, fans of the Boston Red Sox are more likely to feel pleasure, and exhibit reward-related neural responses, at the misfortunes of the archrival New York Yankees than other baseball teams (and vice versa)—especially in the midst of a tight playoff race. (How much fans take pleasure in the misfortunes of their rivals is also linked to how likely they would be to harm fans from the other team.)

Just as a particular person’s group membership can be flexible, so too are the relations between groups. Groups that have previously had cordial relations may become rivals (and vice versa). Indeed, psychological and biological responses to out-group members can change, depending on whether or not that out-group is perceived as threatening. For example, people exhibit greater pleasure—they smile—in response to the misfortunes of stereotypically competitive groups (e.g., investment bankers); however, this malicious pleasure is reduced when you provide participants with counter-stereotypic information (e.g., “investment bankers are working with small companies to help them weather the economic downturn). Competition between “us” and “them” can even distort our judgments of distance, making threatening out-groups seem much closer than they really are. These distorted perceptions can serve to amplify intergroup discrimination: the more different and distant “they” are, the easier it is to disrespect and harm them.

Thus, not all out-groups are treated the same: some elicit indifference whereas others become targets of antipathy. Stereotypically threatening groups are especially likely to be targeted with violence, but those stereotypes can be tempered with other information. If perceptions of intergroup relations can be changed, individuals may overcome hostility toward perceived foes and become more responsive to one another’s grievances.

The flexible nature of both group membership and intergroup relations offers reason to be cautiously optimistic about the potential for greater cooperation among groups in conflict (be they black versus white or citizens versus police). One strategy is to bring multiple groups together around a common goal. For example, during the fiercely contested 2008 Democratic presidential primary process, Hillary Clinton and Barack Obama supporters gave more money to strangers who supported the same primary candidate (compared to the rival candidate). Two months later, after the Democratic National Convention, the supporters of both candidates coalesced around the party nominee—Barack Obama—and this bias disappeared. In fact, merely creating a sense of cohesion between two competitive groups can increase empathy for the suffering of our rivals. These sorts of strategies can help reduce aggression toward hostile out-groups, which is critical for creating more opportunities for constructive dialogue addressing greater social injustices.

Of course, instilling a sense of common identity and cooperation is extremely difficult in entrenched intergroup conflicts, but when it happens, the benefits are obvious. Consider how the community leaders in New York City and Ferguson responded differently to protests against police brutality—in NYC political leaders expressed grief and concern over police brutality and moved quickly to make policy changes in policing, whereas the leaders and police in Ferguson responded with high-tech military vehicles and riot gear. In the first case, multiple groups came together with a common goal—to increase the safety of everyone in the community; in the latter case, the actions of the police likely reinforced the “us” and “them” distinctions.

Tragically, these types of conflicts continue to roil the country. Understanding the psychology and neuroscience of social identity and intergroup relations cannot undo the effects of systemic racism and discriminatory practices; however, it can offer insights into the psychological processes responsible for escalating the tension between, for example, civilians and police officers.

Even in cases where it isn’t possible to create a common identity among groups in conflict, it may be possible to blur the boundaries between groups. In one recent experiment, we sorted participants into groups—red versus blue team—competing for a cash prize. Half of the participants were randomly assigned to see a picture of a segregated social network of all the players, in which red dots clustered together, blue dots clustered together, and the two clusters were separated by white space. The other half of the participants saw an integrated social network in which the red and blue dots were mixed together in one large cluster. Participants who thought the two teams were interconnected with one another reported greater empathy for the out-group players compared to those who had seen the segregated network. Thus, reminding people that individuals could be connected to one another despite being from different groups may be another way to build trust and understanding among them.

A mere month before Freddie Gray died in police custody, President Obama addressed the nation on the 50th anniversary of Bloody Sunday in Selma: “We do a disservice to the cause of justice by intimating that bias and discrimination are immutable, or that racial division is inherent to America. To deny…progress – our progress – would be to rob us of our own agency; our responsibility to do what we can to make America better."

The president was saying that we, as a society, have a responsibility to reduce prejudice and discrimination. These recent findings from psychology and neuroscience indicate that we, as individuals, possess this capacity. Of course this capacity is not sufficient to usher in racial equality or peace. Even when the level of prejudice against particular out-groups decreases, it does not imply that the level of institutional discrimination against these or other groups will necessarily improve. Ultimately, only collective action and institutional evolution can address systemic racism. The science is clear on one thing, though: individual bias and discrimination are changeable. Race-based prejudice and discrimination, in particular, are created and reinforced by many social factors, but they are not inevitable consequences of our biology. Perhaps understanding how coalitional thinking impacts intergroup relations will make it easier for us to affect real social change going forward.