A person's preference for being a 'lark' or 'an owl' is determined by genes, a study has found.
Researchers in Europe have carried out the study and discovered that every cell in the body contains a clock, which can be affected by various genes.
According to them, the brain's hypothalamus -- that acts as a central clock for the body by synchronising all the individual cells -- controls the reason when a person wants to go to bed or get up.
"People know whether they are larks or owls. The interesting part is that they are not all larks or owls for the same reason, and this research addresses the molecular cause of their early or late behaviour. What is really nice here is that by looking at clocks in peripheral tissues, we have for the first time been able to look, by proxy, at the molecular mechanisms in different human individuals that allow them to sense time in the brain.
All in all, I find it quite incredible that skin cells can tell us something about a process as complex as human behaviour," The Daily Telegraph quoted lead researcher Prof Steve Brown of the University of Zurich as saying.
According to Prof Brown, skin cells can be tested to reveal if a person has a genetic propensity to like lie-ins, burn the midnight oil or get up at the crack of dawn.
The researchers came to the conclusion after they took skin biopsies from 28 volunteers and grew their cells up in the lab.
Subsequently, they measured how fast the 'clocks' in the skin cells 'ticked' and then compared these results with questionnaires showing whether each subject was an early type or a late type.
The researchers found that the skin cells from extreme early risers had the shortest glowing periods, whereas those from very late risers had the longest -- the results of the study have been published in the Proceedings of the National Academy of Sciences journal.
