Parents are supposed to sleep when the baby sleeps. Industrial work culture does not allow this. One of the many things leading the "Western" lifestyle to extinction.
The babies I know yet don't sleep like adults which means that you will be up at night at random hours that you are not used to and I think this has nothing to do with industrial work culture.
That 6-8 hours of uninterrupted sleep is just a "dream" :).
I recall, as a twins dad, I did not have 2+ hours of uninterrupted sleep till they are 2 years old. (This depends on the kid though).
This varies, you still see some polyphasic sleep in countries that have very hot middle of the days, Greece + Spain off the top of my head. An intentional waste of daylight because the cooler mornings and evenings are better, but industrialisation has still reduced the frequency of these practices.
This is funny in how cut and dry it is. My friend, do you have kids?
It's my theory that crying evolved as a trait because it forces parents to go find some place safe lest a predator finds them, thus ensuring the helpless kid can grow in safe environments.
Note that there is no mention of sleep in there. That's bonus round if you get it.
I recall, as a twins dad, I did not have 2+ hours of uninterrupted sleep till they are 2 years old. (This depends on the kid though).