I am generally an early riser, and therefore a superior person.  My teenage son sleeps late into the day, a typically lazy Gen Z slacker. 

These 'chronotype' stereotypes are of course outdated, but deeply ingrained in cultural references and social assumptions.  And neither is particularly helpful in explaining why we may feel so tired, regardless of when we retire or rise each day.

Very interesting concepts below on sleep, the notion of 'social jet lag' and how we might better regulate our internal clocks.  

And, I think, some insights that might be helpful for future projects?