BTW, if I understand correctly, the main reason why the life expectancy at birth was over twice as short in pre-industrial civilizations as it in present-day developed world was the much larger childhood mortality, but the expected remaining lifespan for someone who has made it to (say) 40 hasn’t increased by much more than a decade since palaeolithic times. If this is the case, and if the diet was actually the reason for the extraordinary longevity of pre-WW2 Okinawans, even though they had a similar life expectancy at birth as present-day developed countries they would have had a different mortality curve with more childhood mortality and less adult mortality. (Also, if those hypotheses are right and Okinawans had kept their traditional diet while adopting modern hygienic and healthcare standards, their life expectancy at birth would likely have exceeded 90 years.)
but the expected remaining lifespan for someone who has made it to (say) 40 hasn’t increased by much more than a decade since palaeolithic times
I’m pretty sure that’s too low—I remember consulting some table which put high medieval French adult life expectancy in the 50s, which would be 2 decades or so different rather than 1 decade.
Er… Yes. I’ve found this. So a 40-year-old in ancient Rome would have lived 23 more years in average, whereas the corresponding figure for the US in 2003 was 39.5 years.
BTW, if I understand correctly, the main reason why the life expectancy at birth was over twice as short in pre-industrial civilizations as it in present-day developed world was the much larger childhood mortality, but the expected remaining lifespan for someone who has made it to (say) 40 hasn’t increased by much more than a decade since palaeolithic times. If this is the case, and if the diet was actually the reason for the extraordinary longevity of pre-WW2 Okinawans, even though they had a similar life expectancy at birth as present-day developed countries they would have had a different mortality curve with more childhood mortality and less adult mortality. (Also, if those hypotheses are right and Okinawans had kept their traditional diet while adopting modern hygienic and healthcare standards, their life expectancy at birth would likely have exceeded 90 years.)
I’m pretty sure that’s too low—I remember consulting some table which put high medieval French adult life expectancy in the 50s, which would be 2 decades or so different rather than 1 decade.
Er… Yes. I’ve found this. So a 40-year-old in ancient Rome would have lived 23 more years in average, whereas the corresponding figure for the US in 2003 was 39.5 years.
Don’t feel bad—you were at least informed enough not to give a ridiculous answer like ’40 years’.