Learn to Love Your Body Clock
A set of 12 genes appears to control the times that individuals prefer to go to bed and wake up. Though gender is usually not a factor, women appear to be earlier risers than men. One's preference seems to be set from birth, though teenagers typically perfer to stay up later than they might later in life.
Working against one's chronotype can cause serious problems both in the workplace and at home. A job requiring one to work late into the evening, for instance, is a poor fit for early risers. Married couples with confilcting chronotypes may experience friction. There is also evidence that those who work late shifts are more prone to illnesses and accidents.
Understanding chronotypes can take us a long way toward helping people become more productive in the workplace, and happier and healthier in other aspects of life.
Sources: RedNova, Minding the Planet