Is 8 Hours Of Sleep Enough?

We are often told we need 8 hours of sleep every day. Do you wonder where the number comes from? Well, it seems the number is quite random. There is no definitive length of time for sleep, says anthropologist Dr David R. Samson.

- David R. Samson

Being a person who studies human and human behavior, Samson said he could not find evidence for the amount of sleep a person needs. “Most numbers seem to have been given arbitrarily,” he says. As primates, we sleep the least amount compared to other members of the order. However, by comparing human biology to those of close primates, he arrived at an estimated figure of about 7 hours per night.

As humans enter the modern age, we tend to forget that our biology has not caught up with the changes brought about by modernity. For instance, our primate cousins are used to almost pitch-black nights. In today’s scenario, pitch-black nights are a rarity—at least in urban areas— since we have lights in the street, hall, and room. To compound matters, our computers and mobile devices also emit blue light, which is a component of sunlight. However, being exposed to blue light tricks our biological clock into thinking it is still daytime and thus not the right time to fall asleep.