Problem: We each have different preferences for when we go to sleep and when we wake up. Research suggests that about 10% of the population is morning people and 20% are night owls, with the rest of the population somewhere in between. This preference may be influenced by our genes, and relationships have been found between an individual's chronotype (morning person or night person) and patterns of secretion of the stress hormone cortisol. Do you think your chronotype helps you be more or less productive? Do you think there are any ill effects on your health or social life due to your sleep patterns?