How can there be a “white” Hispanic? Why is there a preponderance of “black” players in the NBA? Why is the infant mortality rate of blacks double that of whites in the U.S.?

I’ll give you a hint—it’s not about biology. In humans today, there are not multiple biological groups called “races.” However, race is real and it impacts us all. What we call “race” are social categories. They play a role in our lives, histories, and futures. We talk about race, or avoid talking about it, all the time—but few of us really stop and think about what race really is, and importantly, what it is not.

There is currently one biological race in our species: Homo sapiens sapiens. However, that does not mean that what we call “races” (our society’s way of dividing people up) don’t exist. Societies, like the U.S., construct racial classifications, not as units of biology, but as ways to lump together groups of people with varying historical, linguistic, ethnic, religious, or other backgrounds. These categories are not static; they change over time as societies grow, diversify, and alter their social, political and historical make-ups. For example, in the U.S., the Irish were not always “white,” and despite our government’s legal definition, most Hispanics/Latinos are not seen as white today (by themselves or by others).

This is a difficult concept and it seems to come up again and again, so let me provide a few points to bust the myth and to clarify the reality.

There is no genetic sequence unique to blacks or whites or Asians. In fact, these categories don’t reflect biological groupings at all. There is more genetic variation in the diverse populations from the continent of Africa (who some would lump into a “black” category) than exists in ALL populations from outside of Africa (the rest of the world) combined!

There are no specific racial . There are no genes that make black people in the USA more susceptible to high blood pressure, just as there are no genes for particular kinds of cancers that can be assigned to only one racial grouping. There is no neurological patterning that distinguishes races from one another, nor are there patterns in muscle development and structure, digestive tracts, hand-eye coordination, or any other such measures.

Even something thought to be so ubiquitous as skin color works only in a limited way, as dark or light skin tells us only about a human’s amount of ancestry relative to the equator, not anything about the specific population or part of the planet they might be descended from.

There is not a single biological element unique to any of the groups we call white, black, Asian, Latino, etc. In fact, no matter how hard people try, there has never been a successful scientific way to justify any racial classification, in biology. This is not to say that humans don’t vary biologically—we do, a lot—but rather that the variation is not racially distributed. If you don’t believe me, check it out for yourself by having a look at some of the references below. Seriously, there are no biological races in humans today, period.

Why is busting this myth of a biological basis of race important in a blog for Psychology Today? Because if you look across the U.S., you can see that there are patterns of racial difference, such as income inequalities, health disparities, differences in academic achievement, and representation in professional sports. If one thinks that these patterns of racial differences have a biological basis—if we see them as “natural”—racial inequality becomes just part of the human experience (remember a book called The Bell Curve?). This fallacy influences people to see and inequality not as the products of economic, social, and political histories but more as a natural state of affairs.

While race is not biology, racism can certainly affect our biology, especially our health. Recent work has clearly demonstrated that racial social structures, from access to health care to one’s own racialized , can impact the ways our bodies and immune systems develop. This means that race, while not a biological unit, can have important biological implications because of the effects of racism. This is extremely important for those of us interested in , development, , and health—anyone who wants to use knowledge to make a difference in their own and in others’ lives. Solutions to racial inequalities and the problems of race relations in the U.S. are not going to emerge as long as a large percentage of the public holds on to the myth of biological races.

There is no inherently biological reason that most starting running backs in the NFL are black or most CEOs of Fortune 500 companies are white. Nor is there a “natural” explanation for why race relations are often difficult, but there are lots of interesting social, political, psychological, and historical ones. Go find out what they are (start by checking out the references below), and bust some myths for yourself.