How are "characteristic genetic patterns" related to race, in the way that people like Watson talk about race?

The only mention of race in your quoted text is "into groups analogous to traditional continental racial groups", citing reference 99. So I looked at the four publications for [99]. (Italics mine.)

The first, to Cavalli-Sforza et al., is a book I cannot easily access. The "lay summary" at the NYT says "[Cavalli-Sforza] says more about the related question of human races. One misinterpretation of a human evolutionary tree would be that it shows the branching off of distinct races, with separate histories. A major achievement of human genetics has been exploding the theory that races are genetically distinct. They are genetically only skin-deep: races do differ in a small number of genes that influence superficial features like skin color. But the great majority of our genes are a mish-mash and do not fall into any discrete subcategories of human being. Cavalli-Sforza shows that the European population is the most genetically mixed-up on earth, being a mix of genes from Asia and Africa. He uses this to poke fun at Arthur de Gobineau, the 19th-century French author of the ''Essay on the Inequality of Human Races,'' which helped inspire German racism. De Gobineau, he says, ''would die of rage and shame at this suggestion since he believed that Europeans . . . were the most genetically pure race, the most intellectually gifted and the least weakened by racial mixing.''

The second, Bamstad et al., is pay-walled at https://www.nature.com/articles/nrg1401 . Note that Bamstad and Olson wrote an article titled "Does Race Exist?" for Scientific American, available at http://www.ucd.ie/artspgs/langevo/race.pdf . The intro answers the question: "If races are defined as genetically discrete groups, no. But researchers can use some genetic information to group individuals into clusters with medical relevance."

The 'clusters with medical relevance' is no big surprise, eg, sickle cell mutation and malaria.

The third, Tang et al. (2004), does not link to a full citation. I assume it's for the 2005 publication at https://www.cell.com/ajhg/fulltext/S0002-9297(07)62578-6 . This is the one which mentions "Numerous recent studies using a variety of genetic markers have shown that, for example, individuals sampled worldwide fall into clusters that roughly correspond to continental lines, as well as to the commonly used self-identifying racial groups: Africans, European/West Asians, East Asians, Pacific Islanders, and Native Americans (Bowcock et al. 1994; Calafell et al. 1998; Rosenberg et al. 2002)." I don't follow what the point of the paper is.

The last is to Rosenberg et al. (the same Rosenberg that Tang just cited) at https://journals.plos.org/plosgenetics/article?id=10.1371/jo...

> Our evidence for clustering should not be taken as evidence of our support of any particular concept of “biological race.” In general, representations of human genetic diversity are evaluated based on their ability to facilitate further research into such topics as human evolutionary history and the identification of medically important genotypes that vary in frequency across populations. Both clines and clusters are among the constructs that meet this standard of usefulness: for example, clines of allele frequency variation have proven important for inference about the genetic history of Europe [15], and clusters have been shown to be valuable for avoidance of the false positive associations that result from population structure in genetic association studies [16]. The arguments about the existence or nonexistence of “biological races” in the absence of a specific context are largely orthogonal to the question of scientific utility, and they should not obscure the fact that, ultimately, the primary goals for studies of genetic variation in humans are to make inferences about human evolutionary history, human biology, and the genetic causes of disease.

Of the three papers I understood, all concur that biological race - the topic at issue here - does not have a genetic basis. Which is what I wrote earlier.

If we reject "(biological) race" and instead use "clusters of human genetic trends", then there are a few problems: 1) most clustering algorithms let you choose cut-offs for what defines a "cluster", which is a problem since - as the Rosenberg paper discusses - both clines and clusters are important, 2) if there are hundreds or thousands of clusters then there's a high chance of false correlations (see "p-hacking")

Finally, as I quoted before, multiple lines of research concluded that if there are genetic differences in intelligence, those differences are "very small". Thus, the base position is that there are no large differences. Your statement "there’s every reason to believe that these clusters can be associated with things like intelligence" may be therefore true, but effectively irrelevant. For example, the average intelligence between groups X and Y may differ by 1 unit, and that value is robust, but the standard deviation is 100 units, making it a useless predictor of individual performance.