Chronotype

In chronobiology, the term is used chronotype for the categories of people (day / night) possess physical characteristics such as hormone levels, body temperature, sleep and wakefulness, performance at different times in different forms due to the internal biological clock.

Influencing the day -night rhythm

In humans and other mammals, the hormone melatonin is produced in the retina, the pineal gland and in the intestine, which controls the day - night cycle. The control of the pineal gland is, inter alia, in the suprachiasmatic nucleus of the hypothalamus is localized. There are indications that the different pacemakers have different effects on sleep stages of man. The synchronization with the astronomical day - night cycle of the excitation of the photosensitive ganglion cells in the retina whose maximum light sensitivity at 480 nm wavelength and is therefore in the blue.

Main categories

There are three types: 1 the early risers ( " Lark "); 2 the normal type, which accounts for the majority of the population, and the third late risers ( "Owl "), which is more common after the normal type as the early risers. As shown in the graph ( top right) can be seen, the distribution of chronotype gives greater power a normal distribution ( bell curve ), as is the case also in the distribution of shoe sizes and body sizes.

The Chrono is a genetically created in principle, but varies with age: infants are almost always larks. In puberty and adolescence, the individual chronotype late developing very fast in the direction and reaches 19.5 (female ) and 20.9 (male ) years at an extreme average 4:45 or 5:30 clock clock center of the unperturbed sleep period ( local time). At this age the development bends abruptly in the opposite direction. At the age of about 55 years, the gender gap in average 3:30 clock middle of undisturbed sleep period has disappeared.

A sustainable adaptation to the sleep times of the social environment or occupational needs is very limited by photometric measures possible ( morning light exposure with high color temperature and a sufficient intensity, that is very bright blue light ). The thus inevitably resulting in the majority of the population accumulated sleep debt must therefore be compensated by longer " Sleep in " usually on days off.

In the March 2009 issue of SZ knowledge is mentioned that on average the owl to be wealthier than the lark.