Last year I remember listening to a reviewer on NPR describe a
non-fiction book about the history of darkness. The thrust of the book
was the dramtically different way people behaved during the hours of
darkness before the advent of the electric light bulb. Also discussed
were the odd sleep patterns before electric light and the particular
danger from marauding bands of thugs in the lightless dead of night.
Have tried my hand at searching the Barnes & Noble site without success.