“I’m absolutely puzzled by it,” says Steven Austad. “When I first started looking into this, I expected to find a huge literature on it, and I found virtually nothing. There’s a big literature on ‘Is this a difference between men and women?’ but the underlying biology of the survival difference, there’s very little on that. It’s one of the most robust features of human biology that we know about, and yet it’s had so little investigation.”
