Jefferson Hair-Splitting

The latest issue of Colonial Williamsburg magazine, both in print and online, offers an article by James Breig titled “Hair’s Breadth: Locks Could Be Keys to Jefferson Mystery.” That “mystery” is the paternity of Sally Hemings’s children, but most working historians today don’t see that question as mysterious at all.

The article claims otherwise:

Casual readers might believe the Jefferson-Hemings question was resolved in the affirmative in 1998, when a DNA study was done involving descendants of the Jefferson family and of Hemings. . . . the DNA evidence was shaky enough that it had to be bolstered by other data.

That’s backwards. The documentary evidence of Thomas Jefferson’s paternity was already strong, and the D.N.A. provided extra evidence—more than we have for similar cases of the same age.

As a result, most serious readers see the Jefferson-Hemings question as resolved to a high level of probability. Thomas Jefferson was the only Jefferson to have control over Sally Hemings, to be documented as near her each time she conceived, to let her children become free, to be identified by those children as their father, to be said by contemporaries to be their father, and so on. A smaller number of readers insist that other some other Jefferson(s) was more likely, but their arguments are unconvincing.

I don’t see any indication that the author of this article, James Breig, has a scientific background. For twenty-five years he was editor of the Catholic Diocese of Albany’s official magazine, and he wrote a book titled The Emotional Jesus. It’s also not clear to me how much of the Jefferson-Hemings historiography he’s reviewed. The article cites online reports, but none of the books or scholarly articles on the matter. In writing, Breig was apparently unaware that Eugene Foster, the pathologist who led the 1998 study, died two years ago; the text refers to Foster in the present tense.

The article suggests that surviving samples of Thomas Jefferson’s hair could be tested for the D.N.A. markers that have been found in patrilineal descendants of the President’s uncle Field Jefferson and patrilineal descendants of Sally Hemings. It states:

If the owners of the hair gave permission to test the locks, and if the hair yielded DNA, two big ifs, conclusive proof, or disproof, of a Jefferson-Hemings union would be accessible.

Except it wouldn’t. Simple “DNA” wouldn’t be enough, as the article itself quotes a “researcher in DNA and genetics” explaining:

DNA is inherited half from the mother and half from the father. . . . In one generation, we expect to find half of the DNA in common between father and son. When there is more than one generation in distance, then the DNA in common is a smaller percentage, and it gets harder to make any clear conclusion. When looking farther distances in many generations, then the total DNA in common is much lower.

That problem is compounded by the fact that any surviving “hair-shaft DNA is generally very fragmented.”

That’s why Dr. Foster focused on the Y chromosome in his study. That chromosome gets passed down pretty much intact from father to son, not mixing with the mother’s genes. Perhaps Breig meant the Y chromosome when he wrote “DNA.”

So let’s imagine that at some future date scientists discover methods by which they can test the existing Thomas Jefferson hair samples for the appropriate Y chromosome markers. Curiously, the article doesn’t try that thought experiment and discuss the two possible results.

Result 1: a match between Thomas Jefferson, patrilineal descendants of his uncle Field, and patrilineal descendants of Eston Hemings (who later took the name Eston Jefferson). Would that result offer “conclusive proof…of a Jefferson-Hemings union,” as the article claims? Not according to its own measure of significant doubt. Any doubters who are still alive would continue to insist that some other—any other—Jefferson male was a more likely father than Thomas.

Result 2: no match between that hair and the patrilineal descendants of Field Jefferson and Eston Hemings. In that case, the simplest explanation is that the hair wasn’t actually Thomas Jefferson’s. But what if several separate hair samples with solid provenances all match? The next explanation would be that a Jefferson other than Thomas fathered Eston Hemings, and that Thomas himself was not actually the son of the man we believe to be his father.

Or perhaps, moving down the ladder of likelihood, that Field Jefferson wasn’t actually the son of Thomas’s grandfather, or Field’s sons were both secretly fathered by another man, and that whoever left his Y chromosome in that Jefferson line also fathered a man in the Hemings line. All without leaving a clear trace in the documentary record.

Genetic testing on Thomas Jefferson’s hair would point to his brother Randolph or his sons—the currently preferred candidates of the anyone-but-Thomas-Jefferson crowd—only if it also suggests that Thomas Jefferson was the product of an affair between his mother and unknown man. Not only would that probably be among the last things Jefferson’s self-appointed “defenders” would want, but it would also create a bigger “Jefferson Mystery” than we have now.

All told, this article doesn’t strike me as adding much to the Jefferson-Hemings discussion. Any worthwhile historian or scientist would welcome more solid evidence, and revise his or her thinking based on it, so future genetic advances might conceivably be helpful. But this article suggests that we lack sufficient evidence about the Hemings children now, and that people shouldn’t acknowledge Thomas Jefferson’s likely paternity until science advances further. That seems like a petty way to justify keeping doubt alive.