Large environmental effects on hand grip strength internationally
Hand grip strength is a pretty interesting measurement. Fast to do, reliable, and seemingly irrelevant to most of modern life devoid of physical labor. But it turns out to be…
Sexual maturation and intelligence, Rushton not vindicated
A reader sent me Seb Jensen's blogpost about nerds, which includes the following: People in the Terman’s study of the gifted were more likely to be tall, broad-shouldered, have matured…
Obesity and the secular decline in testosterone
One thing I didn't address in the last post about the decline of everything manly is that obesity is a potential cause of secular declines in testosterone. That's because the…
It’s not just sperm quality decline
Recently Scott Alexander wrote a long piece in his usual fashion Declining Sperm Count: Much More Than You Wanted To Know. He takes the usual meta-skeptical rationalist approach of reviewing…
Heat and the great balls decline
OK, click baity title, but bear with me. In a prior post on Roman fertility decline, I had mentioned a speculative piece arguing that Roman fertility decline was in part…
Book review: David Sinclair – Lifespan: Why We Age—and Why We Don’t Have To (2019)
David A. Sinclair - Lifespan: Why We Age—and Why We Don't Have To, 2019 (free ebook is on libgen) I know Scott Alexander has already reviewed this, but since I…
Testosterone battles
Back in October Razib Khan had Carole Hooven on his podcast. She's the author of a new popsci book on testosterone: T: The Story of Testosterone, the Hormone that Dominates…
Physiognomy: a field ready for scientific revival
People keep asking me about the state of the art re. evidence for physiognomy, so here's a brief review. Phrenology used to be considered legit, and then eventually people realized…
Race gaps in brain size in the very young
Most environmentalists have by now given up denying the existence of racial gaps in head size, but they only retreated a few yards: Nisbett, R. E., Aronson, J., Blair, C.,…
Change in Egyptian skull sizes: -4000 to 150
I often read statistics textbooks. In textbooks, they often use example datasets, some of which are interesting in themselves (e.g. the Boston dataset). In this case, I am reading An…