> Biphasic sleep was probably more common before artificial light
The last time I looked into this theory it wasn’t nearly as robust as I was led to believe. It got circulated as fact for a few years but the people pushing it didn’t really have as much evidence for it as I assumed.
That doesn't make it false. And you'd expect something so radical as extending the lit hours of human life to affect our sleep, as it does many, many other species.
