>>617117That's not entirely accurate. Hunter Gatherers has a high infant mortality rate, but pretty long life spans compared to a lot of pastoralists and agricultural societies over the centuries. Concentrated populations and regular contact with domesticated animals made disease a much bigger killer for "civilised" people, and depending on other factors like climate and sanitation, they could have a dramatically shorter lifespan than h/g tribes.
Human violence also became a much bigger killer as well. Violence between H/G groups was frequent, but small in scale. Usually raids or ceremonial contests. Once people began clustering up in settlements, stock piling resources and controlling more land the scale of violence transitioned from raids to full-blown war which tends to have a negative impact on life expectancy and also opens up a lot more vectors for disease.
