UKC

Taking all the humans who have ever died, what would be the average lifespan?

In reply to MG:

For all the humans that have already died, zero.

In reply to MG:

not a complete answear but some ideas here
https://www.ted.com/talks/hans_rosling_shows_the_best_stats_you_ve_ever_see...

In reply to MG:

given that there are 15 dead for each living person and the life expectancy has only recently started increasing, the overall average would be pretty close to the pre-industrial figure whatever that is (~ 30-35?)

In reply to malk:

Isn't that adult life expectancy ? IE it doesn't count infant mortality in the average.

In reply to malk:

Are there? I thought there were more living than had died?

And is 30-35 the actual life-span for "healthy" environments - ie. Africa, rather than cold, infertile, Northern Europe?

In reply to sjminfife:

Thanks. Some TED talks are superb!

In reply to GrahamD:

life expectancy at birth (inc infant mortality) estimates are in that range: https://en.wikipedia.org/wiki/Life_expectancy
surprised that world life expectancy was still just 31 only 100 years ago..

In reply to MG:

i'd also heard that somewhere, but didn't ring true so i did my research..
http://www.dailymail.co.uk/news/article-2097038/Are-really-people-alive-tod...
(please don't judge me

In reply to MG:

How are you measuring average?
If median or mode, then you'll probably get some large skews from events like the plague, WW1 & WW2.

In reply to edunn:

Such events won´t even figure, as they killed humans all across the ages (or reasonably close to the long term average anyway). I am sure that the average is dominated by low life expectancy of newborns and young children. Once you made it past your teens you could reach your 80's or 90's even in medieval and earlier historic times. Interestingly, people tended to live shorter but had more offspring once they gave up their hunter/gatherer lifestyle and started agriculture!

CB

In reply to malk:

Thanks - interesting

In reply to MG:


Depends who you're counting...

In the introduction of the book '2001: A Space Odyssey', (in 1968) Clarke says:

"Behind every man now alive stand thirty ghosts, for that is the ratio by which the dead outnumber the living".

http://www.goodreads.com/quotes/212808-behind-every-man-now-alive-stand-thi...

I suspect he may have included all the hominidae...

I see the 'Population Reference Bureau' only counts homo sapiens sapiens (and estimates hss evolved 50kya, which seems a bit late to me; I recall 200-100kya as being the estimate for anatomically modern humans. Granted, the population numbers in those periods would be tiny...)

In reply to cb294:


Absolutely. Even in Victorian Britain infant mortality ran at rates that we'd now find appalling. And another factor that we tend to gloss over is the apparent long practice of infanticide in many societies - killing of babies, if only by exposure, to 'weed out' the sick, the weak and the disabled, those judged to be of the 'wrong' gender in the current culture, or simply those that represented too big a demand on family resources at times of stress. I imagine it's hard to factor in those neonate deaths in any calculation of average life span over human history.

In reply to captain paranoia:

if we include Homo erectus then maybe we have outnumbered the stars in our galaxy?

In reply to MG:


I think 'more or less' (R4 maths / statistical programme) proved this urban myth was wrong a year or two ago.

In reply to cb294:


yeah, my grand parents for example. One Granddad born in 1910 had 10 brothers and 2 sisters, most born before him. 3 never reached double figures, a few went early teens, the war got a couple more. The 5 that got past the 1930s and WW2, reached between 70 or 80. Which still gives a rough average of 30 to 35 years. Pretty grim thought really when I've already exceeded that age.

In reply to summo:


daily mail ran it 2012