life expectancy in civilization is easy enough to measure. However, by definition it is very difficult to measure life expectancy of isolated people. First you

life expectancy in civilization is easy enough to measure. However, by definition it is very difficult to measure life expectancy of isolated people. First you must contact them- which starts to change them. Second, you must determine their age, which is a difficult task. The real problem is that using life expectancy by itself is misleading- it mostly represents access to emergency medicine and antibiotics, and the harshness of the environment. We can keep people alive in the USA for a very long time, but that doesn't mean they are healthy.