[tc]

My time spent polyphasic was massively productive. The software and systems I developed during that time formed the foundation of my business. But then I acquired customers, resellers, contractors, and other business partnerships, which made incompatibility with the rest of the world more difficult to handle.

The other major downside is a distinct lack of flexibility. In a monophasic sleeping pattern, if you have a situation and need to work and/or be on phone calls for 24 hours straight, you can do it easily. In a polyphasic pattern, tiredness hits you like a brick wall if you put off a scheduled nap just an hour or two.

Still, if I was starting a new business from scratch, I would seriously consider going polyphasic again for a few months to build the initial foundation.

[holygoat]

… and that's probably one great reason why monophasic sleep 'won' in an evolutionary sense. Robustness usually wins out over efficiency, and not being able to stay awake for a few hours to finish a hunt/avoid a predator/avoid freezing to death/etc. is a pretty big reduction in robustness.

[pqs]

That's an important point. The author says that sleeping "is intuitively an evolutionary disadvantage". That's false, the fact that many species do sleep shows that is is an advantage indeed. Otherwise, there would not be these species.

[jwecker]

having done it for a year and a half, I heartily agree with that summary. On monophasic sleep I'm able to recover from soreness & illness overnight thanks to the extra sleep buffered in. On polyphasic sleep I'm both more efficient and more vulnerable and as you pointed out, less flexible.