The Rate of Black-to-White Passing (C5)


his presentation shows how to compute the rate at which youngsters switch “racial” membership from Black to White after high school. It explains that the rate has been steady and continuous over the centuries. Every year, about 0.10 to 0.14 percent of youngsters born into the African-American community change their “racial” self-identity away from Black to either Hispanic or White.

Four Ways to Attack the Problem

There are several ways of measuring the annual rate of Black-to-White switching. The most direct is to ask people their ethnic self-identity, repeat the question every few years, and then count how many changed their answer from Black to something else.

The U.S. federal Departments of Labor and of Health and Human Services do precisely this (along with many other questions) in longitudinal studies meant to track life-long earnings and health, respectively, of large numbers of Americans.

The Department of Labor’s NLS79 National Longitudinal Survey has interviewed 12,686 young men and women yearly since 1979 to measure their career progress. Each year they are asked the same hundred or so questions.

Between 1979 (when they were 14 to 22 years old) and 1998, 1.87 percent of those who had originally answered “Black,” switched to answering the interviewer’s “race” question with either “White,” “I don’t know,” or “other.”

This comes to 0.10 percent per year. Extrapolated to the Black census 2000 population of 36 million, this comes to about 35,000 individuals per year.

A second approach is to start with the 0.7 percent African admixture found in the White U.S. population today and work backwards. What rate of switching would have produced the observed amount of genetic leakage through the color line?

Assuming a steady rate since 1704, it would have taken an average yearly injection into the White community of the alleles from one person of one hundred percent African genetic admixture for every 43,000 living White Americans (.0023 percent).

In practice, people of one hundred percent African genetic admixture would not have been accepted as members of the White endogamous group and so an adjustment is needed for the fraction of African admixture in those Blacks who switched.

Since some White Americans have as much as 1/4 African admixture, a reasonable estimate is that people who successfully switched from the Black endogamous group to the White had perhaps 1/8 African admixture.

To reach the observed admixture in White Americans today would have required one such person per year switching self-identity for every 5,400 living White Americans. As a fraction of African Americans, this comes to 0.14 percent per year for 300 years.

A third approach is to use the Philadelphia rate at which European-looking children are born into the Black community (one out of every 500) and extrapolate this to the national Black yearly cohort.

This yields about 72,000 individuals as of census 2000, or 0.20 percent per year. Most of these, of course, might choose not to switch.

Finally, Joel Williamson suggests a fourth approach. It is based on the assumption that women are less likely than men to cross the color line permanently.  Approximately equal numbers of male and female infants are born.

But from age 16, millions of African-American men disappear from the census but women do not. In 2000, this came to 2.77 million individuals. Where did they go?

The assumption of this method is that they redefined themselves as White. This approach yields 0.10 percent per year or about 37,000 individuals per year as of census 2000.

The Rate Has Remained Steady Over the Years

The second method (working backwards from today’s observed admixture) assumed that the rate of Black-to-White passing has been steady since 1691, when the endogamous color line was invented.

But the Chesapeake colonies had been in operation for nearly a century when intermarriage was outlawed in 1691. There was much Afro-European intermarriage in British North America before then. Perhaps there has been no Black-to-White passing ever since.

Could the African admixture found in White Americans today merely be an echo of the intermarrying 17th century, rather than evidence of the continual, steady passing of biracials into White society in the 18th, 19th, and 20th centuries?

Or perhaps it is the other way around. Could the African admixture found in White Americans today be the result of intermarriage since 1967, when the U.S. Supreme Court ruled that intermarriage was legal in Loving v. Virginia?

There are three reasons to think that the African admixture found in today’s White Americans is the result of an ongoing process and not the remnant of a one-time event.

First, as mentioned earlier, longitudinal studies show that the current rate of openly avowed Black-to-White ethnicity switching would suffice to yield the observed admixture had it always been going on.

Second, if the White-to-Black gene flow that we know has been going on for 400 years (in the form of the children of interracial unions) had not been balanced by an equal Black-to-White flow, Afro-Americans would have vanished by genetic assimilation.

For example, although Spain and Portugal imported many thousands of African slaves, Iberians of African appearance had vanished by 1700. Similarly, African-looking Mexicans had vanished by 1800, and Afro-Argentines by 1900.

A Leaky Bucket of Genes

To see how this happens, imagine the African-American community as a bucket of genes for Afro appearance. Into the bucket falls a small inflow of genes for Euro appearance, the result of intermarriages whose children join the Black community.

If there were no outflow of genes for Euro appearance, the African-American community would grow steadily more White-looking. Eventually they would vanish as a visible group. This is precisely what happened in Spain, Portugal, Mexico, and Argentina.

(One researcher actually studied Howard University yearbooks going back to its founding to see if students have grown Whiter-looking over the centuries. They have not.)

That a Black-looking population continues to exist in the United States, despite the slow but historically documented intermarriage rate, shows that genes for White looks have leaked out (in bodies of people who switch) as fast as they have fallen in.

Again, the computed outflow necessary to match inflow is between 0.10 and 0.14 percent of the African-American population per year.

Linkage Disequilibrium

The third argument comes from molecular anthropology. It comes from observing “linkage disequilibrium.”

Chromosomes come in pairs. You have two copies of chromosome #1, two copies of chromosome #2, two copies of #3, and so forth. One copy of each chromosome came from your mother’s egg cell; the other came from your father’s sperm cell.

Consider the pair of chromosomes #5. When your body wants to produce a gamete (a spermatozoon if you are male, an ovum if you are female) it must place a single copy of chromosome #5 into the gamete. Which copy does it choose?

Does your body pick one or the other at random (either the #5 copy from you father or the one from your mother)? Does your body simply make up a brand new #5 never seen before?

Does it blend together the material from your two copies–both the #5 copy from your father plus the one from your mother–and mold a new #5 using only half of the resultant mixture (otherwise the new #5 would be way too big)?

In fact, the process lays your two #5 chromosomes side-by-side, like two strands of yarn. It then cuts them crosswise into matching pieces and swaps the pieces between strands.

The cut-and-swap process with two cuts yields one strand that is father-mother-father and another that is mother-father-mother. One of the new patchwork #5 strands then goes into the new gamete.

It makes sense. Only thus can your child inherit your mother’s eyes and your father’s chin. The single #5 in the gamete is not a “blend” in the sense of being homogenized. Instead, it has broad stripes from father and mother.

The width of the stripes is called “linkage disequilibrium.” If one parent is European and the other is African, then the ancestry-informative DNA markers will also fall into the same broad stripes.

The strands are cut and their pieces swapped at each subsequent generation. An individual with barber-pole stripes of African and European DNA within the same strand must be at least a second-generation biracial.

(A first generation biracial would have one #5–from one parent–with nothing but African markers and the other #5 with nothing but Euro markers.)

The chance that in the next generation, the cut-and-swap will happen to hit the precise seams between existing stripes is negligible. So the stripes of African and European DNA get narrower (linkage disequilibrium diminishes) with each passing generation.

A recent one-time wave of intermarriage (since the 1955-65 civil rights movement, say) would result in uniformly high linkage disequilibrium in admixed Americans. This is not observed.

An ancient one-time wave of intermarriage (in the seventeenth century, say) would result in uniformly low linkage disequilibrium in admixed Americans. This is not observed either.

An ongoing slow but steady genetic leakage across the color line for 400 years would result in a distinctive pattern of linkage disequilibrium distribution (stripes of every width occurring with equal frequency). This is what is observed.

Changing Self-Identity is Not Deception

How Can so Many People Falsify Their Paper Trail and Cut all Family Ties?

The rate of Black-to-White ethnicity switching might surprise. How common is it today, when the authorities are more careful about civil records and drivers licenses? How difficult is it for someone to cut family ties and walk away?

A paper trail tracking U.S. “racial” identity was a transitory phenomenon lasting only from about 1880 to about 1965.  Since Alabama ended the practice in 1991, only five states (CT, HI, MS, NC, and TX) still put infant “race” on birth certificates today.

Some states never did, and most stopped in the late 1960s. Neither driver’s licenses nor voter registration cards record “racial” identity in most jurisdictions today. This is why “racial” profiling is controversial.

In Florida, for example, neither the state voter registration web site nor the Flagler County voter registration card has any entry for “race,” while the Alachua County card does.

The few civil records today that capture one’s “race” (jobs, school matriculation, etc) are voluntary. You can check off or write in whatever you want and, with one exception, nobody questions it.  If you look European and claim to be White, nobody cares.

The word “passing” misleads by implying deceit or pretense. Most of those who redefine themselves from Black to White or Hispanic make no secret of their partial African ancestry.

They just do not feel that this trivial fact should stop them from adopting a “racial” self-identity that matches their appearance. There is no need to “cut family ties and walk away.”

Celebrities Publicize Mixed Ancestry

White Americans with openly acknowledged partial African ancestry abound in the entertainment industry. The official web sites of many entertainers claim mixed ancestry. See the following URLs for many dozens of links.

Among these are blue-eyed blondes like Broadway star Carol Channing and Heather Locklear, star of the TV show Melrose Place. At the other extreme are brunettes like Jennifer Beals, star of the movie Flashdance (who has a Black father).

Of in-between skin tone are Oscar-winning film and TV star Martin Sheen (an Afro-Cuban grandmother) and Emmy-winning vocalist Linda Ronstadt (an Afro-Mexican grandfather).

Additionally, there are thousands of Hispanic entertainers, such as Geraldo Rivera, Jimmy Smits, Jennifer Lopez, or Mariah Carey, who proudly claim African as well as Spanish roots through their Latin American heritage.

All methods of estimating the rate of Black-to-White identity-switching converge on the 0.10-to-0.14 percent per year figure derived from the observed African admixture in White Americans.

This suggests that legendary tales of “cutting all family ties” and deception more likely belong to the realm of fictional “passing” novels than to the reality of America’s notoriously mobile society.

As racialism scholar Maria P.P. Root puts it, “It is not uncommon that many individuals emerge out of college years with a different resolution to their racial identity than when they graduated high school.”

For the detailed text of this topic, complete with footnoted references, citations, and all the peer-reviewed material, visit The Rate of Black-to-White Passing.

Frank W. Sweet is the author of Legal History of the Color Line (ISBN 9780939479238), an analysis of the nearly 300 appealed cases that determined Americans’ “racial” identity over the centuries. It is the most thorough study of the legal history of this topic yet published. He was accepted to Ph.D. candidacy in history with a minor in molecular anthropology at the University of Florida in 2003 and has completed all but his dissertation defense. He earned an M.A. in History from American Military University in 2001. He is also the author of several state park historical booklets and published historical essays. He was a member of the editorial board of the magazine Interracial Voice, and is a regular lecturer and panelist at historical and genealogical conferences. To send email, click here.

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