The first prominent theory is for restoration of the brain. This has been a rising and dying fad throughout time. This theory is making a resurgence because new studies are suggesting specific genes only activate during sleep. These genes help with restoration and metabolic pathways
The second theory is energy conservation. The idea behind this theory is when we sleep, we save calories. However, if you compare someone who slept all night with someone who stayed up all night with limited movement, the difference is only 110 calories. This theory is much less credible due to the small difference in calories saved.
The last theory advocates for brain function. It suggests we sleep for brain processing and memory consolidation because when you sleep after learning a task, you are much more likely to learn and remember the information. You also have more creativity after sleeping on information so you are more likely to come up with simple solutions to complex problems. The more important synaptic connections are strengthened after a good night’s rest.
I believe the 1st and 3rd theories are the same. I feel like the 3rd theory gets more into detail about what the 1st theory does. If you combine both theories it would be, “We sleep to restore brain processes and memory consolidation.”
I think sleeping is like checking email. When we sleep, we’re checking all the important emails from work or staying up to date with our fields of study from newsletters we receive. Then we clean out the junk mail and delete it because memes and dad jokes aren’t important and don’t need to be stored in our hard drives.
Then we wake up in the morning. We go through our daily routine. Then we check our email again.