Justin’s Notes

When the Verdict Precedes the Evidence: Lewontin's Non Sequitur and the AAA's Empty Hands

2026-08-24 · AI-generated insight

Read Lewontin's famous passage closely and notice a seam running through it: the first sentence is an empirical claim (most genetic variation lies within groups, not between them), while the second is a moral and political verdict (racial classification is "positively destructive" and unjustifiable). The word "since" does an enormous amount of work bridging the two — and the bridge is shaky in both directions.

The Winegard and Carl note supplies the empirical rebuttal. If populations dispersed into different environments, faced different selection pressures, and were separated by oceans, deserts, and mountains, divergence is what evolutionary theory predicts — not as large differences at any single randomly chosen locus, but as correlated structure across many loci. This is precisely Edwards' later objection to Lewontin: small per-locus differences can still aggregate into highly reliable population structure. Lewontin's statistic is true; the taxonomic conclusion he drew from it doesn't follow.

But the deeper rhyme is with the Coon anecdote. There, the American Anthropological Association condemned a book that almost none of its members had read — the verdict was reached first, and engagement with the evidence was treated as optional. Lewontin's passage is a subtler instance of the same inversion. The moral conclusion ("no justification can be offered") arrives with a confidence the empirical premise cannot support, suggesting the conclusion was fixed and the statistic recruited afterward. Both episodes show scientific authority being spent on moral reassurance rather than earned through analysis.

The irony is that this strategy is self-undermining. If the case against racism is made to depend on an empirical claim — that populations are genetically indistinguishable — then the moral case becomes hostage to future data. Should the claim erode, as Edwards argued it partly has, the ethics erode with it. A moral position that needed no genetic premise was welded to one anyway, and the AAA episode shows what institutions do once they've made that bet: they stop reading the books.

Woven from these notes

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
— Lewontin

A more plausible conception of race, one that is consistent with how careful philosophers and geneticists use the term, recognises that: When humans began leaving Africa around 75,000 years ago, they dispersed across a much greater range of environments than they had previously inhabited. The humans that settled in different geographic regions subsequently came under different selection pressures (e.g. temperature, seasonality, altitude). Natural barriers such as oceans (e.g. the Atlantic), deserts (e.g. the Sahara) and mountain ranges (e.g. the Himalayas) impeded gene flow between different populations for substantial periods of time. When there is limited gene flow between populations that have come under different selection pressures, we would expect them to gradually diverge from one another over via the processes of genetic drift and natural selection.

— Bo Winegard, Noah Carl Superior: The Return of Race Science—A Review
Carleton Coon was one of the greatest anthropologists of the 20th century and a champion of the study of racial differences. In 1961 he was elected president of the American Anthropological Association. It was during this year that Carleton Putnam's infamous book Race and Reason came out. Putnam's book argued that there were significant differences between the races and that this had important political implications. A few anthropologists became upset when they saw the book gain popularity and wanted the AAA to intervene. But they knew that Coon supported the book and that, as a result, having the AAA take action against it would be difficult. So they organized a secret meeting behind Coon's back in order to issue a statement denouncing Putnam's work. Coon found out about the meeting and went to stop it. Upon entering the meeting Coon asked all the association members who had actually read Putnam's book to raise their hands. Only one rose. He then asked for the hands of everyone that had even heard of the book prior to that meeting. Only a few hands rose. None the less, the statement against the book passed. Coon, disgusted by the actions of his peers, resigned from the AAA (1). This incident stands out in the history of science as a particularly clear example of scientists not living up to what people expect of them. People often take what scientists say for granted. They trust that scientists have looked at the evidence rationally and are giving the public as accurate an account of all the relevant facts as they can. When explaining science to laypeople researchers are expected to only make authoritative statements on topics they are knowledgeable of, to not lie about scientific evidence, and to not omit obviously relevant facts. People trust scientists to do these things and so feel comfortable taking what they tell them for granted. (See
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