I've been reading some good books on the subject lately. Some I'd recommend:
https://www.amazon.com/dp/0674065859/
and
https://www.amazon.com/dp/1583334726/
and
https://www.amazon.com/dp/1583334726/
I really find this stuff fascinating. I see family traits: I'm a lark, like my Mother. My son is a night owl, like my husband. Even plants have circadian rhythms, where they do certain things at a given time of day, even if kept in complete darkness or full bright light 24/7. The circadian rhythm is a natural phenomenon. It can supposedly be altered by light therapy and/or chemicals like sleeping pills or melatonin supplements, but I'm not having any success on my own. Interesting stuff.
Karen
