People stay up late easy manipulated 'one night'

Scientists have collected saliva samples of the 211 volunteers (110 male and 91 female) to check the concentration of the hormone cortisol and testosterone. They are also asked to answer the question about whether or not the adventurous, especially about sex and risk financing, besides that they also fill out questionnaires about their sleep description.

The researchers discovered, the group "night owls"-people who love to stay up late in the evening and wake up late in the morning-tend to single and or change the short term emotional relationship. On average, the "night owl" has the guy you love double you belonging to the same "early birds"-the people who go to bed early to get up early.

The results also showed that men are the amount of cortisol and high testosterone than women. However, the sisters belonging to the group "night owls" have a strong faction in the equivalent amount of cortisol for both groups. The objects belonging to the group "night owl", both men and women, generally have high cortisol than normal and easy to implement more adventurous acts.

Professor Dario Maestripieri of the University of Chicago (United States of America) stated, the amount of cortisol can be one of the biological mechanisms that help explain the adventure in your favorite group "night owl". He explains, some people have chronically high intake of this hormone, not related to stress-the condition increases cortisol levels in a short time. These people have a high metabolism, energy levels and irritability.

The amount of high cortisol can also associated with higher cognitive functions. According to Professor Maestripieri, some research has ever shown that successful people, possessing a relatively high amounts of cortisol.

Mr. Maestripieri said that the tendency to become "night owl" or "early birds" in humans depends in part on the characteristics of biology and genetics, but may also be influenced by the environmental factors such as the night shift or child care. The relationship between group "night owls" and the adventure in your favorite is said to originate from search engine strategies you love in the human evolutionary process.

Gender differences affect the sleep appears after puberty and decline steadily or disappear after menopause women. Professor Maestripieri believes that the relationship between "night owls" and risky behavior are derived from evolutionary strategies in search of mates.=