# How did early humans reproduce with a low life expectency? **URL:** \ **Category:** Factual Questions\ **Created:** [March 11, 2016, 6:58am UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634 "2016-03-11T06:58:34Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [March 11, 2016, 10:57am UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/21 "2016-03-11T10:57:23Z")
> [@UDS](#): > > Well, it is a claim about the state of affairs prevailing 50,000 years ago, so I’m guessing there’s a fair degree of conjecture, estimation and finger-in-the-wind involved. all of that, yes, but I generally see a 15-25 range in estimates, I’ve _never_ seen one that low. “Cite?”, I guess is what I’m saying… ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [March 11, 2016, 11:17am UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/22 "2016-03-11T11:17:10Z")
The estimates of lifespans from earliest times to about 1900 usually fall in the range of 20 to 40: > **[Life expectancy](https://en.wikipedia.org/wiki/Life_expectancy)** > > Life expectancy is a statistical measure of the estimate of the span of a life. It is sometimes used referring to inanimate objects, i.e. a building, but is generally used to estimate the average life span of living things, more specifically human life. > This average is calculated based on the year of birth, sex, and region, factoring in the causes of mortality that would most likely affect the particular population. As of 2016, the overall worldwide life expectancy had reached the highest leve... ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 11, 2016, 12:06pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/23 "2016-03-11T12:06:00Z")
No, estimates of lifespans from earliest times to now are all in the 70ish range. Lifespan is not the same thing as life expectancy. ---
**Author:** ![davida03801](https://avatars.discourse-cdn.com/v4/letter/d/b5e925/32.png) [@davida03801](https://boards.straightdope.com/u/davida03801)\ **Post date:** [March 11, 2016, 12:30pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/24 "2016-03-11T12:30:47Z")
Also the woman were having babies at a young age. How young not sure but certainly back then by 15 or 16, if not earlier. ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [March 11, 2016, 12:51pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/25 "2016-03-11T12:51:01Z")
> [@davida03801](#): > > Also the woman were having babies at a young age. How young not sure but certainly back then by 15 or 16, if not earlier. True; but it also seems likely that they breastfed their babies for a long period (up to three years or more), which would have suppressed ovulation and prevented a new pregnancy. ---
**Author:** ![Nava](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@Nava](https://boards.straightdope.com/u/Nava)\ **Post date:** [March 11, 2016, 12:55pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/26 "2016-03-11T12:55:32Z")
As the younger member of a pair of Irish Twins in my class pointed out during Sex Ed: “baloney!” IOW, if that had actually been a good method to avoid getting pregnant, she wouldn’t have been born (neither would my mother’s younger sister, for that matter). ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [March 11, 2016, 1:00pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/27 "2016-03-11T13:00:58Z")
Well, it’s not infallible. But neither are birth control pills. ---
**Author:** ![davida03801](https://avatars.discourse-cdn.com/v4/letter/d/b5e925/32.png) [@davida03801](https://boards.straightdope.com/u/davida03801)\ **Post date:** [March 11, 2016, 1:22pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/28 "2016-03-11T13:22:10Z")
> [@Ignotus](#): > > True; but it also seems likely that they breastfed their babies for a long period (up to three years or more), which would have suppressed ovulation and prevented a new pregnancy. I have a hard time believing that for two reasons. 1st growing up I knew a lot of families with two kids no more than 11-14 months apart. This includes mine as my 2 older brothers are only 12 months plus a few days apart in age. 2nd is from an evolutionary point of view. Since there was a high degree of early childhood demise back then I suspect the evolutionary thing to do would be to have lots of babies. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [March 11, 2016, 1:54pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/29 "2016-03-11T13:54:20Z")
> [@MrDibble](#): > > all of that, yes, but I generally see a 15-25 range in estimates, I’ve _never_ seen one that low. > > “Cite?”, I guess is what I’m saying… I’ve seen that number quoted a lot. Here’s one: > [@](#): > > We have some estimates for the Middle Ages where life expectancy might have been 10-12, which means many people never made it out of childhood. > **[Do the dead outnumber the living?](https://www.bbc.com/news/magazine-16870579)** > > The population of the planet reached seven billion in October last year, according to the United Nations. But what's the figure for all those who have lived before us? and > [@](#): > > Haub (1995) estimates that around 40% of those who have ever lived did not survive beyond their first birthday.[21] Haub also stated that “life expectancy at birth probably averaged only about ten years for most of human history”. > **[World population](https://en.m.wikipedia.org/wiki/World_population#Number_of_humans_who_have_ever_lived)** > > In world demographics, the world population is the total number of humans currently alive. It was estimated by the United Nations to have exceeded eight billion in mid-November 2022. It took around 300,000 years of human prehistory and history for the human population to reach a billion and only 218 years more to reach 8 billion. > The human population has experienced continuous growth following the Great Famine of 1315–1317 and the end of the Black Death in 1350, when it was nearly 370,000,00... ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [March 11, 2016, 1:56pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/30 "2016-03-11T13:56:04Z")
> [@davida03801](#): > > I have a hard time believing that for two reasons. > > 1st growing up I knew a lot of families with two kids no more than 11-14 months apart. This includes mine as my 2 older brothers are only 12 months plus a few days apart in age. > > 2nd is from an evolutionary point of view. Since there was a high degree of early childhood demise back then I suspect the evolutionary thing to do would be to have lots of babies. On the first point: as I already said, it’s a matter of statistical probability, and you’ll certainly find some outliers. (It probably also matters whether the babies were dependent on breast milk as their _only_ food source or had some additional formula.) On the second point, I believe it _does_ make evolutionary sense. If a woman is breastfeeding a child, a new pregnancy, childbirth and the need to nurse an additional child might well reduce the overall chances for _any_ of the offspring to survive. ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [March 11, 2016, 2:04pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/31 "2016-03-11T14:04:14Z")
If you have four kids, and three die in childhood but the fourth survives to their 30s or 40s that gives a life expectancy of about 10. I thought life expectancy for pre agricultural societies was 15-25,id never heard of it as low as ten. ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [March 11, 2016, 2:05pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/32 "2016-03-11T14:05:39Z")
> [@Blake](#): > > Both of which are essentially useless when dealing with infanticide. Archaeological remains and written records don;t generally exist for children drowned at birth. > > based on written records, we know that infanticide was widely practiced and socially acceptable in ancient Rome. But we have very few archaeological remains or written records of such infants. The records we do have consist mostly of offhand remarks that child x was killed at birth or records that the practice was widespread without reference to any specific numbers. What kind of data do we get from today’s hunter-gatherers or those who were hunter-gatherers in recent enough times to be studied? In non-hunter-gatherer groups like ancient Rome, food shortages wouldn’t have been as much of a problem. So in what situations would they practice infanticide? ---
**Author:** ![Mighty\_Girl](https://avatars.discourse-cdn.com/v4/letter/m/7bcc69/32.png) [@Mighty\_Girl](https://boards.straightdope.com/u/Mighty_Girl)\ **Post date:** [March 11, 2016, 2:10pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/33 "2016-03-11T14:10:49Z")
> [@Nava](#): > > As the younger member of a pair of Irish Twins in my class pointed out during Sex Ed: “baloney!” IOW, if that had actually been a good method to avoid getting pregnant, she wouldn’t have been born (neither would my mother’s younger sister, for that matter). I got an IUD right on the day when I was able to start sex again. Lucky because I soon got my period, though I nursed for 35 months > [@Ignotus](#): > > Well, it’s not infallible. But neither are birth control pills. Any cites? ---
**Author:** ![cmkeller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmkeller/32/118_2.png) [@cmkeller](https://boards.straightdope.com/u/cmkeller)\ **Post date:** [March 11, 2016, 2:13pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/34 "2016-03-11T14:13:41Z")
Ignotus: > [@](#): > > Well, it’s not infallible. But neither are birth control pills. Heh. I can personally attest to both of those. ---
**Author:** ![Shodan](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Shodan](https://boards.straightdope.com/u/Shodan)\ **Post date:** [March 11, 2016, 2:15pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/35 "2016-03-11T14:15:30Z")
> [@davida03801](#): > > I have a hard time believing that for two reasons. > > 1st growing up I knew a lot of families with two kids no more than 11-14 months apart. This includes mine as my 2 older brothers are only 12 months plus a few days apart in age. > > 2nd is from an evolutionary point of view. Since there was a high degree of early childhood demise back then I suspect the evolutionary thing to do would be to have lots of babies. It seems nonetheless to be the case. [Cite](http://www.ncbi.nlm.nih.gov/pubmed/3549114). Humans have an unusally long period of infancy and helplessness. Therefore the strategy of having many offspring and relying on a small minority of them surviving to reproduce doesn’t work as well. The ‘strategy’ that has evolved, therefore, is to have fewer offspring, invest more in each one, and ‘hope’ that enough survive. Regards, Shodan ---
**Author:** ![Mighty\_Girl](https://avatars.discourse-cdn.com/v4/letter/m/7bcc69/32.png) [@Mighty\_Girl](https://boards.straightdope.com/u/Mighty_Girl)\ **Post date:** [March 11, 2016, 2:24pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/36 "2016-03-11T14:24:02Z")
I wonder if this has anything to do with food availability. In the same manner that girls start puberty earlier if they are well-fed. The article doesn’t say. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [March 11, 2016, 2:28pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/37 "2016-03-11T14:28:10Z")
I don’t know why people are bringing up “historical records” when the OP specified 50K years ago. The only hard data that archeologists have is the age of fossil skeletons found, and what they tell us about average age at death, supplemented with some minimal data we might have about “modern h/gs” (keeping in mind that there are no such groups around today that qualify for that category in the sense that our 50K years ago ancestors did). Fossil skeletons being such rare occurrences, one can expect our estimates of LE to come with rather large error bars. But if we really want to talk about those historical records cited during medieval times, some of that is going to be skewed, if you will, by periodic episodes of plague that ravaged Europe. I put “skewed” is quotes only because those were natural events and shouldn’t be ignored altogether-- but it also might be informative to looks at LE for plague and non-plague periods. ---
**Author:** ![MandaJo](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@MandaJo](https://boards.straightdope.com/u/MandaJo)\ **Post date:** [March 11, 2016, 2:40pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/38 "2016-03-11T14:40:40Z")
> [@davida03801](#): > > I have a hard time believing that for two reasons. > > 1st growing up I knew a lot of families with two kids no more than 11-14 months apart. This includes mine as my 2 older brothers are only 12 months plus a few days apart in age. > > 2nd is from an evolutionary point of view. Since there was a high degree of early childhood demise back then I suspect the evolutionary thing to do would be to have lots of babies. Nursing is most effective at stopping ovulation when you are nursing a lot–if you are supplementing with formula, or if the baby is also eating solid food (and so nursing less), it becomes less effective. Do you really know how often your mom , or your friends’ moms nursed, and whether or not they used formula for night feedings, or when they switched to solid food? Depending on your age, it’s really very possible they didn’t nurse at all, and even if they did, doctors used to recommend starting at least a little solid food very early, like six weeks. ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [March 11, 2016, 3:08pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/39 "2016-03-11T15:08:02Z")
Chronos writes: \> No, estimates of lifespans from earliest times to now are all in the 70ish range. \> Lifespan is not the same thing as life expectancy. Yes, I should have written “life expectancy.” In any case, the estimates generally given for average life expectancy from prehistoric times to about 1900 are all in the range of 20 to 40 years. The book that CJfromSanAndreas is quoting from is thus considerably different in saying that it was 10 years. Please, CJfromSanAndreas, tell us what book you’re quoting from so we can check it and compare it with other sources. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 11, 2016, 3:13pm UTC](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634/40 "2016-03-11T15:13:00Z")
The life expectancy for oysters is pretty close to zero, since maybe one in a million fertilized eggs makes it to reproductive age (although if they do so they can survive for a long time). Yet somehow they manage to be abundant in places. [Previous page](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634.md?page=1) [Next page](https://boards.straightdope.com/t/how-did-early-humans-reproduce-with-a-low-life-expectency/748634.md?page=3)