The evidence that segmented sleep was the norm does not appear to be particularly strong, but it certainly has enough historical references to suggest it was common. Further, I don’t think segmented sleep was done for the purpose of reducing sleep need. Correct me if I’m wrong.
Segmented sleep, what silver claims to be doing, was the norm of human society before electric lighting.
The evidence that segmented sleep was the norm does not appear to be particularly strong, but it certainly has enough historical references to suggest it was common. Further, I don’t think segmented sleep was done for the purpose of reducing sleep need. Correct me if I’m wrong.
To put it another way: segmented sleep with an alarm clock was never the norm.