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The heritability of fertility makes world population stabilization unlikely

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131–140 of 154 posts

Re: The heritability of fertility makes world population stabilization unlikely

#131
post #62

Earlier quoted context omitted.

If it was advantageous for us to have lots of children, then women would have a dozen at a time, rather than one. There are plenty of mammals that do that. There’s clearly a tradeoff there and the selective pressures for humans tend to lean toward fewer. Not sure where we’ll end up, but time will tell.

The size of the human brain makes this physically impossible.

Ok, explain triplets. https://en.wikipedia.org/wiki/Multiple_birth

Re: The heritability of fertility makes world population stabilization unlikely

#132

All of my grandparents come from big families. My grandmother on my father's side comes from a family of 12 children. Yet my grandmother only had 4 children and my father only 2, and now I only have 1. This is an anecdote, but I don't think heritabiliy has anything to do with it. Large families simply happen due to poverty. When poor, you want more children because there's strength in numbers. Plus the women are stay…

Funny that people are "too rich" to have kids. Or that poverty means you have more of them. Are we sure it is not due to access to contraception?

Re: The heritability of fertility makes world population stabilization unlikely

#133

Earlier quoted context omitted.

Would you then also argue that two smart parents have a much higher chance of having a smart kid than two of average intelligence? If not, why not?

I think you might be misinterpreting the parent. When they refer to education reducing potential, they mean higher education levels generally correspond with a lower birth rate, for a variety of reasons. So smart parents having smart children does seem to fit with that. Or am I misunderstanding what you're getting at?

I did mean the "genetic heritability" part of intelligence, if all other factors stay the same (i.e. assuming a scenario as described in the paper, where no environmental factors change) and everyone gets the same level of support in education etc.

Hope that helps to clarify.

Re: The heritability of fertility makes world population stabilization unlikely

#134
post #123

Earlier quoted context omitted.

I don't really understand how that is relevant for the discussion in this thread.

If anyone thinks the paper is wrong, they are stating that the measures of those values are wrong. The rest is inevitable.

I do not really understand what you mean with "The rest is inevitable", for example I do not know what exactly you mean with "the rest".

Re: The heritability of fertility makes world population stabilization unlikely

#135
post #131

Earlier quoted context omitted.

The size of the human brain makes this physically impossible.

Ok, explain triplets. https://en.wikipedia.org/wiki/Multiple_birth

Three and twelve are very different from each other. Even three is very rare and often comes with complications.

Re: The heritability of fertility makes world population stabilization unlikely

#136
post #75

Earlier quoted context omitted.

But your anecdote is exactly what is explained in the article: the new environment (such as contraceptives) which lead to your ancestors having less kids, will cause increased selection on fertility traits in the future. This will reverse the trend of decreased fertility. Traits that will be selected: a desire to have more kids, physiological changes that cause resistance against contraceptives, tendency to have twin…

That makes sense from an evolutionary/ biological perspective- it’s like contraceptives appear to nature like a filter - a global pandemic, an extinction event of sorts. So those who nevertheless have more children - ipso facto- pass down their trait of having larger families despite the availability of a baby pill. Fascinating hypothesis. My next question would be if there is a biological link to religion and fertil…

Yes, religiosity is inheritable. It's been proven with twin studies. Therefore, if religious people have more kids, having more kids is inheritable. (and also the world becomes more religious)

https://www.newscientist.com/article/dn7147-genes-contribute...

http://blogs.discovermagazine.com/gnxp/2006/11/heritability-...

Re: The heritability of fertility makes world population stabilization unlikely

#137
post #114

Earlier quoted context omitted.

>> There does seem to be darker political overtones that are exacerbated by commenters > Are we reading the same comments section? Which specific comments are you talking about? The comments section I read seemed quite apolitical, except for this particular sub-thread. Please. >> Low-IF journals are easier to publish to by definition. > (...) By definition, Low-IF journals are journals whose papers are less-cited (th…

>Please. No, you please. I'm genuinely trying to reach a better understanding of your side. What comment did you think was the most political, outside of this sub-thread? Was it the one by car12 [1] which pointed out a quantitative observation about Muslim fertility rates and imagined a future where Islamic parties gain a bigger voice in politics through demographics? If so, what is it about that that's so political?…

Thank you, really good example for that.

This is also a good one:

> If an antibiotic doesn't wipe out its target, then its target's numbers will be devastated in the short-term, but in the long-term, its target will evolve immunity to the antibiotic and ultimately recover.

> If you think about it, contraceptives are extremely similar to an antibiotic whose target is human beings. We're still living in the short-term when the antibiotic seems to be effective.

Without any further detail or reasoning, just by "thinking about it" (whatever the author meant by that, he did not elaborate), the author draws a pretty extreme conclusion. This seems to be a rather unscientific, political attempt to reply to the original question:

> If this is true, then how do they explain population stabilization in, e.g., Europe, and other developed areas? Why shouldn't what worked for Europe work for the rest of the world?

Re: The heritability of fertility makes world population stabilization unlikely

#138

I'm sceptical of this result. Most previous research suggests that in countries where immigrants are able to assimilate, second-generation fertility levels converge with local social norms: https://paa2008.princeton.edu/papers/80042

Those immigrants haven’t started the evolutionary process in question, since they have, by definition, only been exposed to a modern developed economy for one or two generations.

Which "evolutionary process in question" do you mean? Isn't the point that it is NOT about an evolutionary process?

Re: The heritability of fertility makes world population stabilization unlikely

#139

The main factors currently in determining family size is not genetically heritable, but cultural. Culture appears to be heritable but that is just because culture tends to be passed down. Culture can change fast in either way, towards more children or less. This does not mean we will be stable but rather culture matters. For example soon as a member leaves a conservative religion stream and shifts to a more liberal s…

>> Also if a women gets an education her fertility drops and the more education the lower the fertility. This means uneducated women (for whatever reason, religious or other) will inherit the earth. If educated women tend to be those with more genetic talents, and in aggregate this may be the case, then this is quite a problematic trend long term.

So is there any reason to believe that last "if" is true? Why would that be a problem anyway, as we can simply make sure schools are in good shape to educate those children, no matter the education level of their parents?

Re: The heritability of fertility makes world population stabilization unlikely

#140
post #123

Earlier quoted context omitted.

If anyone thinks the paper is wrong, they are stating that the measures of those values are wrong. The rest is inevitable.

I do not really understand what you mean with "The rest is inevitable", for example I do not know what exactly you mean with "the rest".

If you accept the heritability for age at first birth has not been measured wrong, then the hypothesis put forth by this paper will come about.

Perhaps I over stated the case by saying inevitable. It's quite feasible that the consequences of highly fertile people overbreeding will be a reduction in civilizational complexity, which will lowerthe total population.

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