Genes play a major role in determining whether someone is a night owl or a morning person, says a study in the journal Proceedings of the National Academy of Sciences.
German and Swiss researchers found that each cell of the body has an internal clock that can be affected by various genes.
They also found that skin cells can be used to measure the speed of a person's body clock, BBC News reported.
These findings could help improve diagnosis of sleep disorders and conditions such as Seasonal Affective Disorder (SAD), a type of winter depression.
In this study, the researchers took skin biopsies from 28 volunteers and grew the skin cells in a lab. They measured the speed of the "clocks" in the cells and found that, in most cases, the results matched up with the behaviour of the cell donors, BBC News reported. – (HealthDay News)
Switch for body clock found