Justin’s Notes

Single Loci vs. Combinations: Both Notes Can Be Right

2026-07-21 · AI-generated insight

Read together, these notes stage the most famous quarrel in the biology of race—and reveal that its two sides are not actually contradicting each other on the facts.

Lewontin's arithmetic is sound: for any single randomly chosen gene, roughly 85% of variation sits within populations and only ~6% tracks racial classification. Winegard and Carl are equally correct: skulls can be sorted into groups with ~80% accuracy using just two variables. How can both hold? Because Lewontin measures one locus at a time, while classification exploits the correlations across many loci at once. Small per-trait differences, when they point in the same direction across dozens of features, compound into reliable joint distinctions. This is precisely the objection A.W.F. Edwards would later name "Lewontin's Fallacy"—the leap from low variance-per-locus to "no taxonomic significance" ignores the information carried by combinations.

What makes the pairing sharp is that Lewontin's own text quietly concedes the fragility of his conclusion. Notice how much of his passage is spent worrying that the 6.3% figure is "sensitive to our racial representations"—that splitting Hindi and Urdu speakers, or unlumping Melanesians, would raise the between-race component, and that a purely genetic clustering would produce categories that "lump certain Africans with Lapps." These are not the caveats of a settled measurement; they are admissions that the number depends heavily on which populations you sample and how you draw the boundaries. Filed, appropriately, under "Bias in Scientific Measurement."

Then comes the tell: Lewontin pivots from a contested statistic straight to a moral verdict—classification is "of no social value and is positively destructive." Winegard and Carl mirror this move in the opposite direction, invoking 80% accuracy to rebut the charge that classification is "ipso facto racist." Both are smuggling normative conclusions out of the same underlying data.

The genuine synthesis is uncomfortable for partisans: the empirical dispute was largely resolved by distinguishing per-locus variance from multivariate structure. What remains is not a factual disagreement but a values disagreement wearing a lab coat—each side reaching for whichever framing of the numbers licenses the ethics it already prefers.

Woven from these notes

The primary reason that natural philosophers began to classify humans into different races is that human populations look different from one another. Their skin colors, hair textures, facial structures, and stature all differ, often in predictable ways. Furthermore, these differences reflect their divergent geographical origins. In fact, researchers can classify human variation by continent quite accurately using only data from the human skull. (They are able to correctly classify human skulls into black and white Americans with about 80% accuracy, using only two variables.) Therefore, despite the common charge that racial classification is ipso facto racist, and that most Enlightenment typologies of human variety were motivated by prejudices and a desire to rationalize imperial domination, ordinary people and Enlightenment philosophers also took to classifying human differences for the mundane reason that such differences actually exist.
— Bo Winegard, Noah Carl Superior: The Return of Race Science—A Review
It is clear that our perception of relatively large differences between human races and subgroups, as compared to the variation within these groups, is indeed a biased perception and that, based on randomly chosen genetic differences, human races and populations are remarkably similar to each other, with the largest part by far of human variation being accounted for by the differences between individuals. Human racial classification is of no social value and is positively destructive of social and human relations. Since such racial classification is now seen to be of virtually no genetic or taxonomic significance either, no justification can be offered for its continuance.
— Lewontin