> 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.)

That is the only mention of the word "skull" in the entire article. They link to an article from the American Journal of Physical Anthropology to support this claim. What is the problem with citing peer reviewed research to back a statement about empirical fact?

Quillette is a very thinly disguised far right publication, and mainstreaming BS theories of 'race science' is an incremental project that has historically turned out badly. Here's a more detailed treatment of the article's flaws, including the commentary of someone whose scientific work is cited in the article. https://uncommongroundmedia.com/quillettes-attempt-legitimis...

And their discussion about skull measurement was not handwavey. It made one very specific assertion and provided some evidence. Again, they may be wrong, but your description of what happens in that article is not an accurate representation of reality.