Being an early bird or night owl is more than a matter of preference: A person’s natural rhythms are dictated by 351 genetic variants, scientists have found. New research published in Molecular Psychiatry shows that sleeping out of sync with that inborn body clock makes a person more likely to experience depression, anxiety and reduced well-being. Researchers from the UK University of Exeter used genetic data on more than 450,000 people to determine their natural body clocks, including whether they identified themselves as a morning or evening person. Data from the digital wrist devices of 85,000 people was also used to measure the “social jet lag” of variations in sleep patterns between work and free days—when early birds stay up late to socialize on weekends or night owls wake up early for work. The researchers found that being genetically programmed to be an early riser protects against major depression and improves well-being, perhaps because society’s 9-to-5 working pattern coincides with early risers. Generally, morning people had a lower BMI and were older, more likely to be female, of higher socioeconomic status and less likely to be current smokers than evening people.