Life expectancy has historically been skewed downwards by terribly high infant mortality rates, not by masses of folks dying at say 40. If half your population

Life expectancy has historically been skewed downwards by terribly high infant mortality rates, not by masses of folks dying at say 40. If half your population dies after 60, the lucky ones, and half before 2, your average "around 30 ish" life expectancy isn't particularly predictive.