Paleolithic sleep patterns are similar to modern sleep patterns

Health Effects of Sleep Deprivation - Science Kids - click to enlarge

Research on sleep patters from our paleolithic ancestors found that an 8 hour sleep pattern was not the norm.  This according to CNN - Sleep like your ancestors. 

According to the Washington Post, three of the existing hunter gatherer tribes slept an average of 6.5 hours per night.  This is very similar to the average measured hours of sleep for the UK.  The British sleep times average 6 hours and 39 minutes per night according to the Great British Bedtime Report - 2013.

From the Washington Post, the paleolithic ancestors were much healthier on measures of chronic disease indices of BMI, and blood pressure.   The authors speculate that the we are unhealthy because we are unhealthy and it may not be due to lack of sleep.

Conclusion:

Cut yourself a bit of slack if you aren't sleeping 8 hours.  It is important to sleep as fatigued individuals have more accidents, it allows people to reduce toxins in the brain and  allows the brain to work on diffuse learning wiring connections while you sleep.  It is a myth that our ancestors slept more.

Memory and Sleep - Penny Lewis - 7 minutes