In addition to your wake- and bedtimes, the length of your PER3 gene also dictates how much sleep you need. Early birds need more, while night owls need less. As far as your mind is concerned, you're still working. Their peak productivity occurs in the mid-morning and dips during the mid-afternoon slump. Talk to a friend. Subscribe to our monthly newsletter to find out about new content, features and more happening at Tuck!