人類睡眠時間的影響?

Regarding to the sleeping habit, I once read an interesting report from a US scientist. I do not remember his name in specific, but his argument is as the following.

The US scientist believes that the sleeping habit for all living things is psychological requirement rather than physical requirement. It is just an organ in our brain to make us sleep.

He brought up some examples. The sleeping habit for many animals is depended on their eating and hunting habit. However, the more physical activities do not equal to more sleeping hours. Cat normally sleeps for 15 hours a day, but they are not exercising actively for the rest of 7 hours. In contrast, dogs tend to be more active, but they share similar sleep habit as cats.

The US scientist also suggested that the prisoners in old day may be punished and caged in a room without a window if they violated rules or regulations in jail. In a room without a window, sleeping in daytime or nighttime have definitely no influence on them. Also, it does not seem to have any different with their sleeping habit, for example number of hours of sleeping time. It suggests that the idea of sleeping in daytime being more efficient and sufficient than sleeping in nighttime is just merely because we knew that it is daytime and nighttime. Therefore, it is more likely to be a psychological issue.

Finally, the US scientist added that if a person maintains a constant sleeping habit. For instance, that person sleeps at 9pm and wakes up at 8am 7 days a week and 52 weeks a year. There is no differential for him to spend the whole day to relax on the beach from work hard in office. He will feel sleepy at 9pm and wake up at 8am.

It somehow proves that sleeping is for psychological satisfaction rather than physical requirement for all living things. The sickness, which arises from not enough of sleep, is due to the violation of the schedule set by our brain. It is a rope-pulling effect between us and our brain.