Why Sleep?

Sleep.  We get so little of it.  Three quarters of Americans don’t even get eight hours per night.  In spite of (or because of) that we seem obsessed with it.  Sleeping pills are advertised all the time and there are natural substitutes for sleeping pills you can try on the market.  In addition to that there are mattresses of various designs, shapes and sizes.  All guaranteed to give you a good night’s sleep.

But if you stop to think about it, our need to sleep just doesn’t make sense.  There we are, prone, immobile for a (recommended) eight hours.  In the wild, that sounds like a downright invitation to be eaten.  A vulnerability we humans are very aware of—as evidenced by the fact that some of our most famous attacks on one another have been carried out at night.  So, why do we need to sleep at all?

The amazing answer to this question is that we don’t know.  There are currently three dominant scientific theories: Sleep conserves energy (this makes sense in evolutionary terms when the mammals who need less energy win out); sleep heals (you know how people tell you to drink lots and sleep when you’re sick?); and sleep seems to have a role in repairing our brains as we age and forming them when we are young.  There is yet one more theory I found intriguing: we need sleep to clean our minds of all the junk we collect there during the day.  All these theories may be true or there may be another we have not yet thought of.  But the fact of the matter is that we don’t know why we (and all other mammals) need sleep.

We do know two things: many people are trying to figure out why we need sleep and we do, most definitely need it.  We can survive longer without food than we can without sleep.

So have a good night’s sleep everyone!

 

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