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.
[1]http://humancond.org/_media/papers/bouchard04_genetic_influe...
Genetic Influence on Human Psychological Traits
There is now a large body of evidence that supports the conclusion that individual differences in most, if not all, reliably measured psychological traits, normal and abnormal, are substantively influenced by genetic factors. This fact has important implications for research and theory building in psychology, as evidence of genetic influence unleashes a cascade of questions regarding the sources of variance in such traits. A brief list of those questions is provided, and representative findings regarding genetic and environmental influences are presented for the domains of personality, intelligence, psycho- logical interests, psychiatric illnesses, and social attitudes. These findings are consistent with those reported for the traits of other species and for many human physical traits, suggesting that they may represent a general biological phenomenon.
FRANCE: "We show a convergence towards French standards that differs across groups of origin. Women of Southeast Asian descent deviate from the fertility pattern of their parents, while those of Turkish descent preserve their parents’ cultural heritage. These different paths of adaptation between groups partly reflect cultural distance between parents’ country and host country. They also depend on family social capital, family structure, and family values. Access to a higher level of education is a crucial factor in erasing differences between groups" https://hal.archives-ouvertes.fr/hal-02081758/document
Not all religions have the same effect on the outcomes, ignoring that in the studies is misleading.
I guess it shouldn't be hard to conceive where Islamic parties start having a major voice in elections because of demographics.
Overall religion is secondary at best, but economically weak tribal/familiy social nucleus cultures vs established nation states that provide reliable social safety not just for relatives.
"It's the Economy, stupid", look at fertility rates of Saudi Arabi, Iran, UAE Poland vs Nigeria.
And what was found is that females from south-east Asia had a big drop in fertility whereas Turks continued to have large families, comparatively.
So, no, the above research specifically disproves your argument.
Not quite to the extent of some white European populations, sure, but very far from the "breeding like rabbits" image that politicians use to drum up fear among uninformed voters.
> the "breeding like rabbits" image that politicians use to drum up fear among uninformed voters
The fertility rates of muslim immigrants are far higher than the natives which will lead to a decisive demographic and political shift, which is what those politicians are talking about.
So if first generation migrants have a greater fertility, it can indeed affect demographics to a large degree. Because you need exactly one generation to do so. Obviously.
And it should also be obvious that lower fertility stems from multiple factors. Birth control is one, modern work structure is the other. I am certain there are more.
Then the environment changes in one, or in two ways. People move to another country, or not, and their culture gets exposed to modernity/the demographic transition. If they move to another country the culture they’re surrounded by will change, which will change when their children think it’s appropriate to marry, how many children they want, etc. It will do nothing to their genes, including their desire to have children.
But all over the world the selection is ongoing. As time goes on the proportion of the population that wants lots of children increases and so do the number of large families.
Genetic and sociological explanations can both be true at the same time. Mormons have more children than average for sociological reasons. They value and honour child rearing and family life far, far more than normal Americans. People whose parents had 6+ children also have more children than average, possibly partly due to role model effects, but mostly because they like children. There’s nothing incompatible about these explanations.
Isnt it obviously true? If you don't breed you don't pass on your non breeding genes, if you do breed....
Living organisms are literally breeding machines, that's all they really do. Natural selection favours those who do it better.
And, going one further, in the past people had children as a matter of rote. Now, it has to be a deliberate, overcoming the obstacle of modernity, in a sense. In the same way smallpox had a habit of reducing the population's potential, so too (by a different mechanism) does education, birth control, abortion, etc. A subset of the population will effectively become immune to those things.
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?
Hope that helps to clarify.
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!
Anyway, I often hear that claim of 50-80% but I can never find the publications backing up that claim. Can you list some, please?
“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. Here's a (now fairly old: from 2016) GWAS study on human reproductive behaviour: https://www.ncbi.nlm.nih.gov/pubmed/27798627
They show genetic correlations between reproductive traits and other behavioural traits in Figure 3. 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?