I think you will find the studies relate to placing different factors of a persons circadian rhythms in contention with each other. Such studies show that the

I think you will find the studies relate to placing different factors of a persons circadian rhythms in contention with each other. Such studies show that the natural balance of the sleep portion of the wake/sleep cycle shifts towards 1-10 am for young men and becomes more resilient. The "day/night" cycle is the external cycle that interacts only to tune the sleep/wake cycle. Suggesting that the sleep/wake cycle and the day/night cycle should be aligned, and that such is natural, is incorrect. I'll link you some papers when I get home. However, in the mean time, I suggest you re-read some of those studies you are claiming to habe read.