Hope you're sitting down, gentlemen: A new study says that homo sapiens made a huge leap in abstract and symbolic thought 50,000 years ago because their skull-shape "feminized" and testosterone levels went down, Pacific Standard reports. Experts at Duke University analyzed over 1,400 modern and ancient skulls for a difference at the 50,000-year mark, and found that brows got lighter, faces rounder, and the upper area of the face became shorter at this crucial time, Duke Today reports. Such a "feminized" look, they say, corresponded with less testosterone affecting the skeleton.
This would have made humans less aggressive and more cooperative at a time when art, cultural exchange, and technological innovation was on the rise. It may have also heightened male attractiveness, signaling what the study calls "a greater propensity to invest in parenting effort." While the study doesn't really pertain to modern people, the researchers say, "it’s important to note that the potently biggest leap forward in human technology was likely accomplished through advances in cooperation, not intelligence." (Read about a supposed "Hobbit skull" found in a cave.)