A 3x3x5x3 design with ChatGPT-5.4, Claude 4.6 Sonnet, and Gemini 3.1 Pro; three names, five domains, and three registers produce 135 responses through public interfaces. Grounded theory generates ten phenomena; a second coder reviews the corpus. A 136-feature pipeline applies ANOVA, chi-square, regression, a 1,000-bootstrap, K-means, and HDBSCAN.
135 responses collected in 27 sessions between 26 and 30/04/2026. Each ethnic group is represented by one name and no participants from those groups are included. No explicit negative racial bias was coded. The Middle Eastern name triggered cultural inference in 6 of 9 cases; the other two triggered 0 of 18. Phenomenon classifiers reported F1 from .847 to .974. K-means and HDBSCAN mainly recovered experimental domains.
One name per group confounds ethnicity with the specific name and tokens. There are no stochastic repetitions per prompt. Public interfaces hide parameters and change. Automated detectors include features close to the labels they predict. The sample is small, English-only, and exploratory. It does not demonstrate population effects or colorblindness. It does not validate ten independent psychological constructs. It does not attribute differences to architecture or alignment philosophy.