Humans have turned many wild animals into cuddlier creatures. We’ve domesticated wolves into dogs, boars into barnyard pigs and mountain goats into livestock that do yoga. But in addition to helpful animals and adorable pets, humans may have also domesticated an altogether different creature: Homo sapiens.

The so-called self-domestication hypothesis, floated by Charles Darwin and formulated by 21st century scholars, is now popular among anthropologists. They see parallels between changes