Abortion is just one of the things that female mammals do. We don’t know the ins and outs of its mechanisms yet, and they probably differ between species. But if rodents, equines, and primates have all developed some version of the Bruce effect, then we should stop thinking that human abortion is something unique. The way we do it—using human gynecology—is different, but ending a problematic pregnancy in response to social stress is something a lot of mammals do.
