Answers are grounded in this paper and cite their sources.
The relationship between aging and daily "circadian" behavior in humans is bidirectional: on the one hand, dysfunction of circadian clocks promotes age-related maladies; on the other, aging per se leads to changes and disruption in circadian behavior and physiology. For the latter case, recent research suggests that changes to both homeostatic and circadian sleep regulatory mechanisms may play a role. Could hormonal changes be in part responsible?
No takes yet. Share an insight, caveat, or question.
Brown et al. (2011) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: