This is not a particularly unique thought or question to be asked in the book, but perhaps because I've been house sitting for someone in a rural setting it left a greater impression on me. It wasn't even all that important to the book, but Lib's LIB is about my thoughts and not necessarily what the author thought was interesting. Poo-poo, author, poo-poo.
Why do we whisper in the dark? Most of the predators that we have left to stalk us would hear us anyway, and would be more likely to run away if we were loud than not. Yet there's still this tendency to lower our voices. Some of this might be common courtesy, although if you ask my mother-in-law people are abandoning that left and right. I'm inclined to agree with her, although less with her surmise that it was and is inevitable. (I at least hope people will eventually get tired of being rude to each other.)
I don't know about you, but the dark has always been more fascinating to me than the daylight. There's something about not being able to see the things around me clearly that makes me think differently about them. Nothing has really changed, except my physical perception, but somehow that is enough. I usually find myself more creative at night; I get good ideas, even though I'm often too tired to follow them. Of course, in the daylight those good ideas are sometimes rejected, but I like to think they wouldn't come to me without that change in perception.
I think we whisper in the dark so we don't disturb those ideas. I know people who are night owls who enjoy their schedule specifically because they know they have all the time in the world to sit and think and truly develop their ideas without interruption. We also do secret or private things in the dark. Not that we're limited, but it's easier to find the time to do them when the day is over. We don't have to worry about sneaking away or being caught or not completing our tasks for the day. We can do those secret, private things without the extra guilt of having dirty dishes in the sink or stealing time at work.
Maybe we whisper in the dark because we want to keep it the way it's always been: different from the daylight.
My review can be found on Goodreads.