Supplementary Materials
Big Data, Deep Roots
Published paper
Van Pelt, D. & Kirkegaard, E. O. W. (2026). Big Data, Deep Roots: Correlating Surname Genetic Ancestry and Socioeconomic Status across Millions of Americans. Comparative Sociology, 25, 239–280.
Publisher and DOI · Author's ResearchGate page
The published paper contains the full methods, additional figures, discussion, and supplementary analyses. The blog post summarizes selected results; its three figures come from the project.
Reading the counts
The 31.6 million headline refers to the sum of the processed metric datasets in Table 1 (approximately 31,596,478 records). These overlap: occupation ratings are derived from government employment records, for example. It is not a count of distinct people.
| Metric | Processed records | Records with surname ancestry coverage |
|---|---|---|
| Criminal records | 3,802,050 | 3,398,752 |
| Salary | 14,124,647 | 9,243,123 |
| Occupational prestige | 9,803,723 | 8,314,726 |
| Wikipedia intellectuals | 65,571 | 51,464 |
| Physician licensure | 3,800,487 | 2,036,473 |
23andMe provided ancestry estimates for 11,008 surnames; 10,989 appear in the final prediction plot and the game. Wikipedia was analyzed separately and excluded from the S factor.
Migration statistics
Choudhury, Ganguli, and Gaulé's study followed the 2010 JEE cohort. Its 36%, 62%, and nine-out-of-ten figures describe migration abroad among the top 1,000, 100, and ten scorers, respectively. The United States was the main destination, not the only destination. The post uses this distinction when summarizing the paper and thread.
Iranian American survey
The demographic table on page 19 of PAAIA's 2025 survey reports 24% Muslim, 34% with a four-year degree, and 45% with postgraduate education. The latter categories total 79%, so the post uses 79% rather than the 87% mentioned in the paper's discussion. These are survey estimates from 425 respondents.
