a bias towards larks explained

“Wisdom teaches us that none but birds should go out early, and that not even birds should do it unless they are out of worms.” Mark Twain

Somebody who is asleep is clearly not up and working. And the fact that someone is asleep is more noticeable, public, and unusual during the day than during the evening. Two people may spend exactly the same amount of time asleep and awake, but the one who is always up and about at 6 AM will end up with a very different reputation from the one who usually gets up at 9 AM.
Irish writer Robert Lynd was on to something when he said, “No human being believes that any other human being has a right to be in bed when he himself is up.”

via {center for environmental therapeutics}