Sure, little by little, millennia by millennia, we’ve been adding years to the average human life, they will say. Most of us didn’t get to 40, and then we did. Most of us didn’t get to 50, and then we did. Most of us didn’t get to 60, and then we did.12 By and large, these increases in life expectancy came as more of us gained access to stable food sources and clean water. And largely the average was pushed upward from the bottom; deaths during infancy and childhood fell, and life expectancy rose. This is the simple math of human mortality.
