Although some will tell you that more sleep is better, recent research from Duke University found that humans get a great deal less sleep than our closest animal relatives due to the fact that we have evolved to get better sleep quality in less time.
The team of researchers created a database of sleeping patterns across hundreds of mammals and used statistical techniques to create a visual of each species' position in the primate family tree. Upon analyzing it, they found that humans are very short sleepers, getting an average of seven hours per night in comparison to other primate species that need as many as 14 to 17 hours per night.
"Humans are unique in having shorter, higher quality sleep," said David Samson, co-author of the study, in a press release.
What makes our sleep more efficient? Humans spend a smaller portion of our sleeping time in the light stages of sleep and longer periods of time in deeper stages of sleep. For example, approximately 25 percent of our overall sleep time is spent in a deep stage called rapid eye movement (REM) sleep, whereas other primates such as mouse lemurs and mongoose lemurs barely ever go above five percent.
The researchers believe that this evolutionary shift towards shorter, more efficient sleep could be partly due to the transition of sleeping in "tree beds" to sleeping on the ground as we now do. Once on the ground, humans would have had to be more cautious in terms of predators and thus minimize sleep time while maximizing its efficiency.
The findings were published in the Dec. 12 issue of Evolutionary Anthropology.