Early Birds or Night Owls: Who Are More Productive?

I used to be a forced early bird – had to wake up early for one particular summer job which started at 7 a.m. Had to take the TTC bus because the subway didn't open until 9 a.m. on Sundays. Needless to say, I lasted only one month. In high school, I would stumble groggily to class, barely making it there for 8:30. By the afternoon, I would wake up and get my second wind. I wrote my best essays at 10 p.m.

A London School of Economics study concluded that people with higher IQs tend to be night owls who slept in. On the other hand, scientists from the University of Bologna inferred that early birds are more conscientious people. The American Psychologist Association indicated that ‘morningness’ is
associated with greater positive emotions in all age groups, perhaps because early risers get greater exposure to the sun, thereby getting a greater dose of vitamin D, the energy vitamin.

Any number of books (print or electronic) address the issue of internal time: