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The heritability of fertility makes world population stabilization unlikely

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Re: The heritability of fertility makes world population stabilization unlikely

#141
post #114

Earlier quoted context omitted.

>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…

You didn't explain what's political about any of those posts.

Just because there's a political party committed to believing "the sky is red" doesn't make it political to say "the sky is blue".

I was the author of the "contraceptives are like antibiotics" comment btw. The point wasn't to make any extreme conclusion (I admit I can see how it could be taken that way in e.g. an abortion debate, but only by reading words between the lines that simply are not there). The point of that comment was not to score points in any political debate but to suggest an intuitive way to think about the results of the paper. Some commenters make the error of extrapolating straight lines, essentially saying "We observe reverse-correlation between education and birthrates over several decades, therefore they must be reverse-correlated forever". I pointed out an example, in a similar context[1], where such linear thinking would be wrong ("We observe the bacteria numbers are declining, therefore they must continue declining forever").

[1] Similar in the sense that they both involve living populations, population growth and decline, growth and decline caused by particular changes, etc.

Re: The heritability of fertility makes world population stabilization unlikely

#142
post #140

Earlier quoted context omitted.

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.

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

> 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.

First you argue that if the paper is right, the measurements must be right. Then you argue that if the measurements are right, the paper must be right. Both arguments seem illogical, especially when used in that combination.

Re: The heritability of fertility makes world population stabilization unlikely

#143
post #141

Earlier quoted context omitted.

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…

You didn't explain what's political about any of those posts. Just because there's a political party committed to believing "the sky is red" doesn't make it political to say "the sky is blue". I was the author of the "contraceptives are like antibiotics" comment btw. The point wasn't to make any extreme conclusion (I admit I can see how it could be taken that way in e.g. an abortion debate, but only by reading words…

> Just because there's a political party committed to believing "the sky is red" doesn't make it political to say "the sky is blue".

Just to clarify this. Why is the former political and the latter not? Because one is false, and one is true?

I would argue that something is scientific or political no matter if its true or false. What counts is the way you try to convince others that it is true. Just as an example:

> The point of that comment was not to score points in any political debate but to suggest an intuitive way to think about the results of the paper. Some commenters make the error of extrapolating straight lines, essentially saying "We observe reverse-correlation between education and birthrates over several decades, therefore they must be reverse-correlated forever". I pointed out an example, in a similar context[1], where such linear thinking would be wrong

Here, you do not really explain why the intuitive thinking used by other authors (extrapolation) is less valid than the intuitive thinking you suggest: you do not explain why the comparison between humans and bacteria in the area of reproduction is valid, given the huge differences between humans and bacteria.

So when you say that "I admit I can see how it could be taken that way in e.g. an abortion debate, but only by reading words between the lines that simply are not there", that is kind of true: it is about the words that are not there - the words you have to provide to explain why your theory might not be wrong.

Re: The heritability of fertility makes world population stabilization unlikely

#144
post #51
post #5

Could someone with more time than me summarize how they reached the conclusion that fertility was heritable? It seems very counter-intuitive unless I'm misunderstanding the precise meaning of "heritable" that enables them to draw this conclusion.

The three law's of behavioural genetics: “First Law: All human behavioural traits are heritable. Second Law: The effect of being raised in the same family is smaller than the effect of the genes. Third Law: A substantial portion of the variation in complex human behavioural traits is not accounted for by the effects of genes or families.” Beyond that though, the genetics of human fertility is pretty well understood.…

> You might find it helps you develop an intuitive understanding. Happy to answer questions if you have any.

Isn't "intuition" basically the opposite of "science"? Shouldn't we try to answer questions about the latter, not the former?

Re: The heritability of fertility makes world population stabilization unlikely

#145
post #48

I have always wondered whether something like this could be observed. I wonder, shouldn't this be already observable? I would look not at the median/mean fertility, but on the outliers on the upper end. If the share increases/becomes more expressed in social groups that are not associated with a large number of children otherwise, one should see indicators that the theory is has some thruth. Also, we are talking abou…

This study ( https://www.pnas.org/content/114/5/E727 ) measured the speed at which selection against cognitive ability is occuring in the Icelandic population (they measured this genotypically rather than phenotypically). The rate at which it occurs is meaningful on the scale of our lifespans. Same is probably true for fertility rates, but as fertility is being selected for directly (rather than the indirect effect o…

> That this is not obvious to everyone is just a testiment to how little people understand about evolution.

Exactly because things are not obvious, they need to be explained. As long as you do not explain the things you call obvious, you cannot judge if people do not understand a topic.

Re: The heritability of fertility makes world population stabilization unlikely

#146

Earlier quoted context omitted.

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?

The premise of the article is that fertility is heritable, which means an evolutionary process is taking place that will overcome the demographic transition.

Re: The heritability of fertility makes world population stabilization unlikely

#147
post #141

Earlier quoted context omitted.

You didn't explain what's political about any of those posts. Just because there's a political party committed to believing "the sky is red" doesn't make it political to say "the sky is blue". I was the author of the "contraceptives are like antibiotics" comment btw. The point wasn't to make any extreme conclusion (I admit I can see how it could be taken that way in e.g. an abortion debate, but only by reading words…

> Just because there's a political party committed to believing "the sky is red" doesn't make it political to say "the sky is blue". Just to clarify this. Why is the former political and the latter not? Because one is false, and one is true? I would argue that something is scientific or political no matter if its true or false. What counts is the way you try to convince others that it is true. Just as an example: > T…

>Why is the former political and the latter not?

In that example, I'd say neither one is political. Now, if the one side started saying "Blue-skyers should be deplatformed", THAT would be political.

>Here, you do not really explain why the intuitive thinking used by other authors (extrapolation) is less valid than the intuitive thinking you suggest

I suppose if you really want to get down to brass tacks, my "contraceptives are like bacteria" comment was an instance of paradeigma, a rhetorical procedure popularized by Aristotle in which one attempts to help guide one's audience by presenting analogous anecdotes.

The difference between that and the extrapolators is that the extrapolators, at least in most cases I think, are unaware that they are falling prey to an unjustified extrapolation. None of them have come out and explicitly defended the implicit logic "Inverse correlation for the past several decades => inverse correlation forever". If someone DID want to explicitly defend it, they might use paradeigma right back at me, saying something like, "The inverse correlation is like the sunrise. We've observed the sunrise for a long time, and the sun will certainly continue to rise". Of course, such a rhetorical maneuvre would be unlikely to win many debate points, because the audience isn't stupid and can clearly see that analogy's too much of a stretch!

>it is about the words that are not there

But then basically you can twist anything at all into being political. I could say "1+1=2" and you could say "That's political! You're trying to imply something about binary genders, since you didn't explicitly throw out a disclaimer that you aren't trying to imply something about binary genders!"

Not that I'm trying to accuse you of consciously doing that... I think I'm guilty, myself, of sometimes reading politics into things that are apolitical. It can be particularly tempting to subconsciously categorize threads into teams, like, "This guy is X party and is on my side", "This guy is Y party and is the enemy". I've been trying recently to stop doing that, because I believe if I can get past that, there's a lot to learn from the people I thought of as enemies.

Re: The heritability of fertility makes world population stabilization unlikely

#148

Earlier quoted context omitted.

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

The premise of the article is that fertility is heritable, which means an evolutionary process is taking place that will overcome the demographic transition.

> The premise of the article is that fertility is heritable (...)

Actually, that was the conclusion, and is exactly the thing that is being disputed.

Re: The heritability of fertility makes world population stabilization unlikely

#149
post #147

Earlier quoted context omitted.

> Just because there's a political party committed to believing "the sky is red" doesn't make it political to say "the sky is blue". Just to clarify this. Why is the former political and the latter not? Because one is false, and one is true? I would argue that something is scientific or political no matter if its true or false. What counts is the way you try to convince others that it is true. Just as an example: > T…

>Why is the former political and the latter not? In that example, I'd say neither one is political. Now, if the one side started saying "Blue-skyers should be deplatformed", THAT would be political. >Here, you do not really explain why the intuitive thinking used by other authors (extrapolation) is less valid than the intuitive thinking you suggest I suppose if you really want to get down to brass tacks, my "contrace…

Your statement was:

> Just because there's a political party committed to believing "the sky is red" doesn't make it political to say "the sky is blue".

Now you say:

> In that example, I'd say neither one is political.

That seems to be a contradiction.

> The difference between that and the extrapolators is that the extrapolators, at least in most cases I think, are unaware that they are falling prey to an unjustified extrapolation.

Yes, and I pointed out that also you do not give an explanation of why your proposed comparison is justified or not. (I do not think we need to involve the term "paradeigma" here, we can just use "comparison")

>> it is about the words that are not there

> But then basically you can twist anything at all into being political.

I don't really see the relation between my and your statement. Very generally: putting out statements without explaining the underlying thinking/reasoning/data at least exposes you to the accusation of being political, or unscientific, sure. Giving more detail, being more transparent about your thinking, explaining underlying concepts/data makes it easier for others to follow your reasoning, but exposes you to someone pointing out a mistake in your thinking. But well, that is science.

> I could say "1+1=2" and you could say "That's political! You're trying to imply something about binary genders, since you didn't explicitly throw out a disclaimer that you aren't trying to imply something about binary genders!"

I do not think that "1 + 1 = 2" falls in the same category as "the reproductive behavior of humans and bacteria are comparable". Therefore, in the example you gave, the answer is actually the political statement, as it brings in the completely unrelated topic of "gender" that no one was talking about and that has nothing to do with anything, just to try to win an unwinnable argument.

Re: The heritability of fertility makes world population stabilization unlikely

#150

Earlier quoted context omitted.

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.

Since the discussion in the thread here seems to have stopped, I'll skip to the conclusion:

Both fertility and intelligence are not as simple as the color of someones eyes. Lots of genes play a role, so the combination of two favorable gene-sets does not necessarily lead to a still favorable gene-set. Therefore, there always seems to be a "regression toward the mean", so don't worry, one or two generations cancel out all "preexisting conditions". Therefore, in every practical sense, both the heritability of intelligence as well as the heritability of fertility are negligible compared to other factors.

Of course children of more intelligent parents tend to get a better education, for example, i.e. those children can develop more of their potential, but here we're back to environmental parameters. But hey, this is good news, because it also works the other way around - dumb parents can have smart kids! So even if dumb people breed like rabbits, we just gotta make sure schools are properly funded to educate those children properly so they can develop their potential!

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