As well as less creepy things, like when you wake up in the morning
PROBLEM: The 24-hour day is inscribed in our biology -- our bodies contain inner circadian clocks that keep time and regulate the rhythms of various functions and behaviors. In part, this clock can be affected by the environment, such as when we travel to a different time zone and adjust to new hours of darkness and light. But other aspects of our circadian rhythm, such as what time of day we're most alert, appear to have a genetic component.
- Forcing a Smile Genuinely Decreases Stress
- People Living in Poverty Are Twice as Likely to Be Depressed
- Cocaine Increases Long-Term Risk of Heart Attack and Stroke
METHODOLOGY: Researchers at Beth Israel Deaconess Medical Center in Boston borrowed data that had been collected 15 years ago from a sleep study at Rush University in Chicago. Unintentionally, that study turned out to be perfect for this new research. First, its subjects had worn a device, called an actigraph, that provided detailed information about their sleep-wake patterns. Second, the subjects were all over the age of 65 when the study was originally done. So by the time the Harvard researchers got to them, many had passed away. They had all also agreed to donate their brains to science. Because of this, the researchers knew their precise times of death. Finally, in the course of the many physical and psychological evaluations undergone by the subjects, they had also had their DNA sequenced.
Using all of this information, the researchers at Beth Israel were able to compare the differing circadian cycles of 537 of the original participants with variations in their genetic makeup. They then replicated their findings with a second group of 38 younger individuals who had been part of a different study at Brigham and Women's Hospital.