This is the first of a two-part series about neurobiology and racism. The second piece will discuss how our experiences affect brain processes.
Picture this: You’re walking in a public park on the way home from work. You hear music playing from a portable speaker and the din of loud voices. You glance over and see a small group of teenage boys. You look away for an instant before hearing a cry. When you turn around, one of the teens is on the ground. Is he hurt? You feel your own heart rate increase. What happened—did he fall or was he pushed? Should you stop and ask if he needs help? Should you look for a police officer? Or should you walk quickly away to avoid potential violence?
In this scenario, your brain most likely changed patterns of activity as it generated a perception of what was occurring around you, how you felt about the situation and your motivation to engage in new behavior as a result. One of the most interesting—and maybe controversial—truths about how the brain works in such a situation, though, is that your brain activity differs depending on whether the boys share your race.
It’s a type of bias that’s insidious, because it happens without consciously thinking about it, yet it permeates different regions of the brain generating widespread consequences for how we think, feel, perceive and react to our environment. And controlling how we think, feel, perceive and react is incredibly difficult, notwithstanding all of the books on the bestseller lists claiming ways to gain control of your inner mind. While you would hope the race of the boys wouldn’t matter, most likely, it would have—at least regarding what’s going on in your brain.
While this unconscious bias differs from what we might consider overt racial discrimination—where we treat people of different races differently—it does refute the contention that we can “see past race.” By the very nature of our brains, we can’t—but can we do anything about it?
Humans: Surviving and Thriving
Since the completion of the Human Genome project back in the early 2000s, scientists have finally been able to put rest the notion that race is a biological phenomenon. There is much more genetic variation within a race than between different races. Yes, there is variation in skin color in the human species, and that variation can be explained by the amount of ultraviolet radiation populations were exposed to during prehistoric times and the resultant genetic adaptation. The term “race,” as people mean it, is a social and cultural construct.
So if race is not biological, why am I claiming that there is a biological mechanism in the brain that predisposes us to racial discrimination? I am not, really. The mechanisms that I am going to explain are tied to our ability to survive and thrive during prehistoric times. Taken together, these adaptations, while each not directly related to racial discrimination, may underlie some of the racial bias that occurs as we interact with one another.
Compared to many other species, humans on the surface are not very impressive. So many other species are faster and stronger than us. Many have natural weapons and defenses that we lack: The golden dart frog, for example, produces enough poison to kill a dozen humans or more. In modern times, however, we discount other species’ advantages because of all the tools and weapons we have built. Speed, strength, fangs, claws and armored shells are nothing compared to what a human can do with a gun. (Humans with guns versus other animals is pretty much like the New York Yankees versus a preschool T-ball team.) But if we went back in time before humans invented and crafted those tools which have transformed our planet, we were just a slow, weak and soft primate species struggling to survive.
So why did humans thrive? For one, we survived in groups. This trait—small groups of a species working together to enhance survival—is hardly unique to humans. The animal kingdom is filled with species that found adaptations in which individual animals work together for their common good—just look at a colony of ants or a flock of geese. Mechanisms of natural selection lead to the most fit of a species to survive and reproduce at the expense of those less fit, and what makes them fit can be based on how well the group does.
Like many such species, humans are territorial, defending their homes and potential food sources not just from other animals, but from other humans. A key difference for humans, though, is that we produce far fewer offspring than many other species, and our children require a tremendous amount of care, support and protection during their first few years of life. As a result, there was a huge evolutionary pressure for humans not only to develop an innate motivation to protect one’s group from others, but also to be able to recognize and respond quickly to the perception of others so that one could identify who is part of the group and who isn’t. One area that may have developed as result of these forces is a region of the brain called the fusiform gyrus, which neuroscientists suspect is crucial to our ability to recognize and respond to faces and most likely is specific to humans.
A second key trait that most likely allowed the earliest humans to thrive is the ability of our brains to categorize things and to perceive patterns in our environment. Again, other species have this ability, most easily seen in other primates like monkeys. This ability is incredibly useful in activities like harvesting fruit: A fruit-producing tree will not always have ripe fruit, and thus an animal that can categorize the tree as one in which food will be produced and recognize the pattern of when the fruit ripens has a huge advantage over other animals trying to harvest fruit. While the prefrontal lobe, which evolved in primates, seems crucial to the task of categorization, brain mapping experiments in humans indicates that our ability to categorize a wide range of items occurs over a large range of our brain space. It’s maybe not surprising, then, that fruit-eating primates tend to have significantly larger brains than other primates.
As humans evolved even larger brains, one consequence is that the human brain became highly tuned to sort individual objects and to place them in generalized categories. For example, recent imaging studies of babies suggest that a region of the fusiform gyrus called the Visual Word Form Area has the capacity to respond to patterns and to categorize visual stimuli so they connect to our language centers. While this area of the brain evolved well before the onset of literacy, the innate capacity to rapidly respond to patterns and categorize has allowed for the development of such human skills as reading. But this also has significance for the way we respond to the racial differences we can see: Isn’t a feature of discrimination the propensity to assign value based on belonging to a category rather than individual merit?
A final brain trait that was likely crucial to early humans is our capacity for associative learning. A fundamental property of brains is the ability of neurons to change how they communicate with one another in response to what the animal is experiencing. This process, called neuroplasticity, is even present in a simple worm called the nematode, which has exactly 302 neurons. One experiment revealed that the nematode can learn to associate an odor with the presence of food, and it most likely does so by changing the release of the neurotransmitter serotonin. As a species with 86 billion neurons, humans have an aptitude for associative learning, and modifying our behavior in response gave us huge advantages, from learning language to developing new tools to transform our environment. Associative learning allows us to link things that have happened in the past and predict what might happen in the future.
All this seems positive, so what’s the problem? For one, scientists have known for a long time that associations can form even if the things being associated are not related. In the nematode experiment, the association between the odor and the food was created artificially by the scientists. The odor chosen was not one that is naturally associated with food—which is why the experiment was so convincing. But the neurons have no insight that this is a false association.
Now imagine a culture that builds associations, either intentionally or unintentionally, of negative behavior and outcomes based on some physical category, like the color of one’s skin. Neurons in our brain change communicative properties to “learn” this association and as a response generates variation in brain activity based on that physical category. Hence, an unconscious bias emerges.
Where Empathy Comes From
These three brain traits—the ability to perceive whether someone is part of our group, to categorize and perceive patterns and to form associations between things we have experienced and encountered—all helped us as a species to succeed in our environment. These traits evolved in their present form in modern humans during times when race did not exist, as almost no prehistoric humans ever came in contact with other humans with different skin color, so there was no reason to socially construct the concept of race. Yet now, with modern humans creating race as a way to group humans into different categories, and with a plethora of information routinely being presented about behaviors and outcomes associated with people based on race, these brain traits may lead to mechanisms that promote racial discrimination.
Let’s go back to the scenario I outlined at the start: If the boys are of a race different from your own, your brain would quickly perceive them as belonging to a group different from yours, categorizing them as belonging to a particular race, perceiving the pattern of behavior as leading to violence and associating with other examples of violence and negative outcomes that you hear and read in the news on a weekly basis. Regardless of how you consciously feel about racial discrimination, the effect of these mechanisms can lead to differences in brain activity that would impact how you perceive, feel and respond to the situation. In short, it would affect your empathy for those boys.
Over the past decade, neuroscientists have conducted clever experiments that have illustrated that a bias occurs in brain activity when one is observing individuals experiencing pain based on whether they are of the same race versus a different race. A typical experiment would have a subject responding to a series of images while their brains were being imaged with an MRI scanner. In some images, the subject would see something that looked painful, like a needle being pressed against a person’s cheek. Brain activity, as detected in the amount of oxygenated blood being delivered to different regions of the brain, are measured and compared.
One of the brain regions in which studies have consistently found differences is the anterior cingulate cortex. This is important because it is also an area that has increased activity when we imagine that we are feeling pain ourselves. The fact that it is also active when viewing others in pain suggests that this is a region that helps create our sense of empathy. Other techniques, such as using an electroencephalogram (EEG) to measure electrical activity in the brain, have been able to isolate that the differences in brain activity due to racial bias occur in approximately 150 milliseconds, faster than our consciousness can register what is actually happening.
Clearly, then, this is very different from a form of discrimination than deciding not to hire someone or to approve a home loan based on race. In those forms of discrimination, individuals are consciously deciding to engage in behavior differently based on someone’s race. By contrast, the scenario I’ve presented here suggests a bias that doesn’t necessarily lead to overt behavior.
But while we can enforce laws to affect blatant behavior, we can’t regulate our thoughts, feelings and perceptions in the same way. The one silver lining in this dark cloud? We created race as a way to categorize people—and we ought to work to find the path to deconstruct race as a way we define ourselves.