Mark Guadagni’s Reviews > Why We Sleep: Unlocking the Power of Sleep and Dreams > Status Update

Morning people and night owls actually is a genetic feature brought upon by evolution. I can no longer look at people who sleep in as lazy (ook maybe I can) because as a tribe we were more likely to survive if some people were able to stay up late and watch over the tribe, meanwhile the other half of the tribe wakes up early--limiting the amount of time vulnerability to predators when the whole tribe is asleep.