That short-sleeping that we're now suffering is a consequence of our lifestyle. It's not a consequence of evolutionary habituation.

I have long been puzzled by the entrenched mentality, and often enforced practice, of longer work hours and less sleep. Innumerable policies exist within the workplace regarding smoking, substance abuse, ethical behaviour, and injury and disease prevention.

It's simply that older adults don't seem to be able to generate sleep efficiently, and that's why they're not getting it.

Matthew Walker Quotes