Life expectancy (at age 0) has increased mainly because infant mortality and child mortality has decreased dramatically, not because people used to collectively live to 30′s and now live to 70′s. Most adults in our ancestral past lived to be about as old as people do in western industrialized nations today.
This is true, but there was also a significantly increased risk of death in young adults from accidents and in women during childbirth; also, “nearly as old as we do now” still means a decade or so off the end.
Yep, I checked from here and there’s still 17 extra years for males and 21 extra years for females in 2011 compared to 1850 in “life expectancy at age 20”.
However, our expected healthspan (the amount of time for which a person is capable of substantial physical activity and not beset by ailments) has gone up considerably in the last few centuries. Perhaps the relatively few people who made it to old age in hunter-gatherer societies might have had similar healthspans, but they constituted a dramatically smaller fraction of the total populace. The average 35 year old today has decades longer of healthy, productive living to look forward to than the average 35 year old 300 years ago (sources available in this book) and while people occasionally remark on, say, 50 being the new 30, it doesn’t seem to leave most people dazzled or mentally unequipped for their new environment.
Huh, I have harbored that misconception for a really long time. Pretty annoyed that I never thought to examine that statistic further (it just sounds so right!). Thank you.
e: regardless of the fact that there is a decade or so of actual increased lifespan between the two periods, this still solidly harpoons my analogy.
Most adults in our ancestral past lived to be about as old as people do in western industrialized nations today.
That sounds iffy to me. Sure, straight comparison of life expectancy at birth is heavily biased by child mortality. So let’s take life expectancy at, say, 25. Are you saying that in “ancestral past” if you made it to 25 you were likely to make it to 70-80? I strongly doubt that, if only for medical reasons. Lack of effective medicine including antibiotics, lack of understanding of public health issues leading to epidemics, parasite load, etc. Plus violence for men and childbirth for women were major risk factors.
Epidemics and parasite load may have been lower than you might think if the populations were more diffuse. Things spread better through a dense population jammed into a refugee camp than through a sparse population.
According to this if you made it to 15 your average life expectancy was around 54.
OK, let’s accept that 54 years number. A US 15-year-old male has the life expectancy of 15+62=77 years and a 15-year-old female -- 15+67=82 years (source). Take the average of 80, more or less.
So basically the life expectancy of a contemporary American 15-year-old is one and a half times larger than the life expectancy of a 15-year-old from a forager tribe. That’s not “about as old”. Besides, hunter-gatherers are known to be healthier than farmers.
Life expectancy (at age 0) has increased mainly because infant mortality and child mortality has decreased dramatically, not because people used to collectively live to 30′s and now live to 70′s. Most adults in our ancestral past lived to be about as old as people do in western industrialized nations today.
This is true, but there was also a significantly increased risk of death in young adults from accidents and in women during childbirth; also, “nearly as old as we do now” still means a decade or so off the end.
Yep, I checked from here and there’s still 17 extra years for males and 21 extra years for females in 2011 compared to 1850 in “life expectancy at age 20”.
More specifically, all the cells in the “2011” row of the “White males” table are around 40% larger than the corresponding cells in the “1890” row.
However, our expected healthspan (the amount of time for which a person is capable of substantial physical activity and not beset by ailments) has gone up considerably in the last few centuries. Perhaps the relatively few people who made it to old age in hunter-gatherer societies might have had similar healthspans, but they constituted a dramatically smaller fraction of the total populace. The average 35 year old today has decades longer of healthy, productive living to look forward to than the average 35 year old 300 years ago (sources available in this book) and while people occasionally remark on, say, 50 being the new 30, it doesn’t seem to leave most people dazzled or mentally unequipped for their new environment.
Huh, I have harbored that misconception for a really long time. Pretty annoyed that I never thought to examine that statistic further (it just sounds so right!). Thank you.
e: regardless of the fact that there is a decade or so of actual increased lifespan between the two periods, this still solidly harpoons my analogy.
That sounds iffy to me. Sure, straight comparison of life expectancy at birth is heavily biased by child mortality. So let’s take life expectancy at, say, 25. Are you saying that in “ancestral past” if you made it to 25 you were likely to make it to 70-80? I strongly doubt that, if only for medical reasons. Lack of effective medicine including antibiotics, lack of understanding of public health issues leading to epidemics, parasite load, etc. Plus violence for men and childbirth for women were major risk factors.
According to this if you made it to 15 your average life expectancy was around 54.
http://www.unm.edu/~hkaplan/KaplanHillLancasterHurtado_2000_LHEvolution.pdf
Epidemics and parasite load may have been lower than you might think if the populations were more diffuse. Things spread better through a dense population jammed into a refugee camp than through a sparse population.
OK, let’s accept that 54 years number. A US 15-year-old male has the life expectancy of 15+62=77 years and a 15-year-old female -- 15+67=82 years (source). Take the average of 80, more or less.
So basically the life expectancy of a contemporary American 15-year-old is one and a half times larger than the life expectancy of a 15-year-old from a forager tribe. That’s not “about as old”. Besides, hunter-gatherers are known to be healthier than farmers.