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You may enjoy this TED talk about the global population leveling off: https://www.ted.com/talks/hans_rosling_religions_and_babies/...

It's where I first heard the term "peak child" or "peak baby" to describe this.

Hans Rosling explains it very well: https://www.ted.com/talks/hans_rosling_religions_and_babies

Cultures have nothing to do with it.

See Hans Rosling's talk on this [1] or see it yourself in data [2]. As soon as education, medicine, economic situation improves, you get a drop to ~2 children per woman across all cultures.

[1] https://www.ted.com/talks/hans_rosling_religions_and_babies

[2] https://www.google.com/publicdata/explore?ds=d5bncppjof8f9_&...

⬐ SketchySeaBeast

While I see that there is a definite trend, if culture had nothing to do with it, why would the Israel and Faroe Islands outliers exist with many more children? And I see a ton of groups there that have the highest life expectancy and < 2 children, all Asian countries. That seems to indicate that 2 is not in fact a magic number at all.

⬐ dmitriid

> why would the Israel and Faroe Islands outliers exist with many more children

"Many more". Israel: 3.11 (down from 4 in 1960s), Faroe Islands: 2.6 (down from 3.2 in 1970s).

Compare to Niger: 7.24.

And especially compare to muslim countries which just love having kids, don't they? Oh, look dropping from 8 kids per woman to around 2 for most of them (some are understandably lagging behind, like Yemen, Iraq, Gaza)

> That seems to indicate that 2 is not in fact a magic number at all.

I said ~2 kids, i.e. about two kids, not exactly 2 kids. There's nothing magic about this number, it's sub-replacement fertility [1]. 2.1 for developed countries, 3.4 for some developing countries. Yes, some nations will dip below 2, can't see how that disproves my words. Neither culture nor religion have anything to do with it. Give people quality of life, education, access to modern medicine, and they stop having 8 kids per woman, and quickly dip to about replacement fertility rates.

[1] https://en.wikipedia.org/wiki/Sub-replacement_fertility

⬐ SketchySeaBeast

Numbers like 1.17 and 1.21 are not roughly two kids, it's half two kids. What wiggle room are we talking here? I was originally responding to someone who said

> On average most woman want two children. But when a lot of them die they will get more (average of 6 around 1800).

and that doesn't seem to be the case.

And you said that culture had nothing to do with it, but clearly the variation in the birth rates (50% to 150% of the ~2) in countries with roughly the same standard of living is due to something.

⬐ dmitriid

If what you said was true, muslim countries would still have 8 kids per woman. They don’t. Just go to the link and play with the slider.

Once again. Slowly.

As people gain access to medicine and education, and as quality of life increased, traditions and religion fly out of the window. Even deeply religious countries like the Gulf states go from 7-8 kids per woman to roughly 2 kids per woman.

These factors trump any other factor in determining how many kids a woman will have.

Once the countries get on more or less the same level in terms of these factors, only then will you see variations due to other things like culture, religion, what not.

Israel is 1.5 times more than other developed countries (and the difference is slowly but surely dropping)? So? Niger is almost 4 times more than other countries.

Medicine, education, quality of life. These three universally affect rates regardless of tradition, religion or what not.

⬐ pixl97

>why would the Israel and Faroe Islands outliers exist with many more children?

Most likely answer, religion. Successful religions grow one of two ways, and generally have encodings for both. That is they tend to have means to convert the non-religious, and secondly, and importantly in this case, have 'strong' rules on having kids. For example, in the old testament Onan was killed for 'spilling his seed' and not impregnating his dead brothers wife.

That said, even in ancient times it appeared that birthrates did go down, as in Greces case, their city state succeeded. This left them open from attack and cultural take over by outside nations and ideals with higher birthrates.

In the modern world we are coming to the point where human labor is not as necessary and has been supplanted by machine labor. Also machine protection, in our weapons of war. This could allow a nation/culture to shrink dramatically while still being able to defend against outside threats. If such a shrinking culture were one that 'grew' by spreading its message to other cultures it may succede to grow and shrink the entire worlds population at the same time. These ideas of disappearing utopia cultures are often touched by science fiction.

⬐ SketchySeaBeast

Oh, I understand all that, but the two arguments made earlier was that culture had nothing to do with it (I'd say religion is in fact part of culture), and that societies move towards having two kids, which doesn't seem to be the case, it would appear that it actually goes lower, much lower.

Yes there are exceptions, but I was talking about the average.

The number 2 comes from the current world wide trend. In developed countries the fertility rate tumbles down but stops at around 2. So it is believed this is the average bottom.

Maybe you like this talk from Hans Rosling: https://www.ted.com/talks/hans_rosling_religions_and_babies

Source: https://www.ted.com/talks/hans_rosling_religions_and_babies

Productivity doesn't need to scale up indefinitely - it just needs to be able to scale up until it's enough.

Silly but simple thought experiment: - 10 people on an island - 2 people can pick enough coconuts for all 10 to eat well - Using a ladder, productivity picks up enough so 1 person can pick enough coconuts for all 10 - A coconut picking robot is developed, picking enough coconuts for all 10 The coconut picking robot's productivity can't scale indefinitely but it doesn't have to.

I am sure you can see the implications of using robots in the real world.

Edit: Speaking of babies, prof. Hans Rosling's TED talks are mandatory. http://www.ted.com/speakers/hans_rosling http://www.ted.com/talks/hans_rosling_religions_and_babies

⬐ kilbasa

I think if you measure productivity in terms of coconuts over man hours, productivity could rise indefinitely if it's at all possible to make robots that repair themselves and don't require any non-renewable resources.

Anyway, I think the first people to lose their jobs would be the ladder makers.

His TED talks are well worth watching too:

* http://www.ted.com/talks/hans_rosling_shows_the_best_stats_y...

* http://www.ted.com/talks/hans_rosling_reveals_new_insights_o...

* http://www.ted.com/talks/hans_rosling_at_state

* http://www.ted.com/talks/hans_rosling_on_global_population_g...

* http://www.ted.com/talks/hans_rosling_the_good_news_of_the_d...

* http://www.ted.com/talks/hans_rosling_religions_and_babies

* http://www.ted.com/talks/hans_rosling_the_truth_about_hiv

* http://www.ted.com/talks/hans_rosling_and_the_magic_washing_...

⬐ Evgeny

There goes my weekend! Thank you so much.

⬐ TeMPOraL

I strongly recommend those talks.

The 'magic washing machine' talk is beautiful. One of my favourite quotes of all time comes from it.

And what we said, my mother and me, "Thank you industrialization. Thank you steel mill. Thank you power station. And thank you chemical processing industry that gave us time to read books."

⬐ agumonkey

IIRC that talk had a powerful ending (beside that quote).

⬐ zo1

Are you referring to the one where he performs sword eating? (I kid you not)

Check out another talk by Hans Rosling where he visually demonstrates that 10 billion figure: .html" rel="nofollow">http://www.ted.com/talks/hans_rosling_religions_and_babies.h...

There's no large scale correlation between religion and procreation. On the other hand, there's a good correlation with wealth/living standards; namely, richer countries reproduce less, poorer countries reproduce more.

Source: .html" rel="nofollow">http://www.ted.com/talks/hans_rosling_religions_and_babies.h....

Completely agree. It's time for the developed nations to start thinking about instituting a http://en.wikipedia.org/wiki/Basic_income guarantee. Unfortunately this doesn't seem to be anywhere even near anyone's radar at this time.

As for reproductive rights, that could be a problem that goes away on its own. I don't mean in the bad way. This TED talk [1], at least, makes a reasonably convincing argument that the world population is heading for a maximum of 10 billion simply due to falling birth rates all over [the peaceful regions of] the world.

[1] .html" rel="nofollow">http://www.ted.com/talks/hans_rosling_religions_and_babies.h...

A bit less pessimistic view is presented by Hans Rosling at a relatively recent TED talk. .html" rel="nofollow">http://www.ted.com/talks/hans_rosling_religions_and_babies.h... Well worth watching.

Sperm count is unlikely to affect the population growth anyway, what we need is to get people out of poverty and proper family planning with access to proper birth control. Then we can "control" the population.

⬐ wesley

What we need is a 1 child policy like in China.

⬐ citricsquid

I don't think that policy is so great. People don't have children just because they can, we need to educate people about children and population growth. My aunt and uncle have an adopted daughter from China, she was abandoned as a result of the one child policy: the policy didn't stop her from being born, but it stopped her from having her biological family.

⬐ pathy

That does lead to other problems, like putting a strain on the welfare system of countries when there suddenly is a huge decrease in the number of people that support those who have retired.

Look at Japan where there are fewer and fewer supporting more and more. It is kinda working for now but what will happen in 20 years? Who knows.

⬐ kalms

My guess? We'll gradually shift back into larger households, with several generations living under one roof. Not that bad, when you come to think of it.

⬐ potatolicious

http://www.brycealcock.com/random/TriviaStats/ChinaPopulatio...

Because it's demonstrably successful at curbing population growth rate? Because during periods of the most aggressive enforcement of the one-child policy, China had its highest growth rate in recent history, 2-2.5x that of the US?

And now, during its period of least aggressive enforcement, but with a rapid pace of industrialization and wealth injection, the growth rate has fallen dramatically?

http://www.indexmundi.com/g/g.aspx?v=24&c=ja&l=en

Or perhaps we want to look at Japan, which without forced abortions, property confiscation, and brutal acts of repression have managed to achieve a negative growth rate?

No matter which way you slice the data, the trend is clear: industrialization, wealth, and stability decrease growth rates, and do so far better than any number of guns and Bibles you can point at people.

⬐ stcredzero

> Because during periods of the most aggressive enforcement of the one-child policy, China had its highest growth rate in recent history, 2-2.5x that of the US?

The fact that China would think to enforce such a policy should give one pause.

⬐ lukifer

Don't forget educating women, which tends to result in fewer children per household.

I am concerned, though, that the temporary lull in overpopulation will be broken by belief systems that encourage large families; by definition, those with a genetic or memetic instinct to have many children will out-populate those without that instinct. (I have a soft spot for the Mormons, but they come to mind here.)

⬐ rohansingh

Memes aren't strictly inheritable in the same way that genes are.

For example, it is completely plausible to advance the argument that children in large families decide to have fewer offspring due to their own childhood experiences. I'm not saying that this is definitively the case or that I have any evidence for it, but it is just as plausible as the conjecture that a propensity for a large number of offspring is perfectly inheritable.

⬐ lukifer

Even if memes are not genetically heritable, they are still transmissible, and therefore still subject to selection pressures. And the more children these families have, the broader the attack surface for large-family beliefs to infect the next generation.

Moreover, I would suggest that genetics do influence tendencies for adopting some memes over others, especially as regarding the instinct to spread genetic material, which is very ancient. I can't cite any scientific support for this idea, but the likelihood seems very strong.

This talk by Hans Rosling makes a pretty reasonable case for decoupling the notion of religion and birth rates.

http://www.ted.com/talks/lang/en/hans_rosling_religions_and_...

⬐ genwin

Does he explain away the correlation in Utah? It seemed a safe bet that Utah has the US's highest birth rate, given Mormonism there. A search confirmed it. (Sorry I'm lazy on video sources.)

⬐ jbrechtel

No he doesn't mention it from what I recall. The data discussed is broader (and more longitudinal) than that trend.

Personally I'd guess the birth rate there is a direct result of the church's push for more children, but I don't really know.

.html" rel="nofollow">http://www.ted.com/talks/hans_rosling_religions_and_babies.h...

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