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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 misunder

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.

mxfh 7y ago
So far the consesus was that migrants from traditonally child rich societies, acclimated already a generation later at local lower levels if prosperitiy and education level was reached as well. So it's the economy and social stability through the state that replaces children as the only "pension and care" provider for retirement. 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 https://hal.archives-ouvertes.fr/hal-02081758/document
- acqq 7y ago
  I suspect that “Southeast Asian” women observed had different religion than those where “fertility pattern of their parents” is preserved. Not all religions have the same effect on the outcomes, ignoring that in the studies is misleading.
  - car12 7y ago
    What it is pussyfooting around is that there is not that drastic of a drop in fertility rates of muslims. I guess it shouldn't be hard to conceive where Islamic parties start having a major voice in elections because of demographics.
    - mxfh 7y ago
      By numbers, global fertility/population trends and religion are not a "muslim" one, that's a made up western "identity" problem. If anything it's catholic to evangelical sectionism, if you look at Western Africa. 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.
      - car12 7y ago
        The post that I was replying to was talking exactly about fertility rates of second, third and beyond generation immigrants in Netherlands. 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.
    - FeteCommuniste 7y ago
      Fertility rates across better-developed majority-Muslim countries have been plummeting: https://www.google.com/publicdata/explore?ds=d5bncppjof8f9_&met_y=sp_dyn_tfrt_in&idim=country:ARE:QAT:SAU&hl=en&dl=en#!ctype=l&strail=false&bcs=d&nselm=h&met_y=sp_dyn_tfrt_in&scale_y=lin&ind_y=false&rdim=region&idim=country:ARE:QAT:SAU:MAR:IRN:TUN:DZA:LBY:KWT:LBN&ifdim=region&hl=en_US&dl=en&ind=false https://www.google.com/publicdata/explore?ds=d5bncppjof8f9_&... 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.
      - car12 7y ago
        How is the statistic of lower dipping fertility rates inside Muslim countries of relevance when talking about: > 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.
- raxxorrax 7y ago
  If you want to know anything about future demographics, just look at a school. Should not be that hard honestly. 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.
- barry-cotter 7y ago
  Desire to have children has been under selection only since the demographic transition. Most of the world has less than two generations of selection, most one, some none. As such we would expect to see a lot of variation in desire to have children. The only group I’d be willing to bet money have notably higher desire to have children than other human populations are the French because that’s where the demographic transition started. For everyone else on average we should expect more or less the same mean and variance. 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.
benj111 7y ago
"how they reached the conclusion that fertility was heritable?" 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.
- mynameishere 7y ago
  It's beyond obvious. Strange that people are arguing against it. 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.
  - j_wtf_all_taken 7y ago
    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?
    - benj111 7y ago
      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?
      - j_wtf_all_taken 7y ago
        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.
DissidentSci 7y ago
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. Here's a (now fairly old: from 2016) GWAS study on human reproductive behaviour: https://www.ncbi.nlm.nih.gov/pubmed/27798627 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.
- j_wtf_all_taken 7y ago
  > 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?
barry-cotter 7y ago
Every other psychological trait is heritable[1], why wouldn’t desire to have children be? [1]http://humancond.org/_media/papers/bouchard04_genetic_influence_psychological_traits.pdf 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.

mxfh 7y ago

So far the consesus was that migrants from traditonally child rich societies, acclimated already a generation later at local lower levels if prosperitiy and education level was reached as well. So it's the economy and social stability through the state that replaces children as the only "pension and care" provider for retirement. 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 https://hal.archives-ouvertes.fr/hal-02081758/document

acqq 7y ago
I suspect that “Southeast Asian” women observed had different religion than those where “fertility pattern of their parents” is preserved. Not all religions have the same effect on the outcomes, ignoring that in the studies is misleading.
- car12 7y ago
  What it is pussyfooting around is that there is not that drastic of a drop in fertility rates of muslims. I guess it shouldn't be hard to conceive where Islamic parties start having a major voice in elections because of demographics.
  - mxfh 7y ago
    By numbers, global fertility/population trends and religion are not a "muslim" one, that's a made up western "identity" problem. If anything it's catholic to evangelical sectionism, if you look at Western Africa. 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.
    - car12 7y ago
      The post that I was replying to was talking exactly about fertility rates of second, third and beyond generation immigrants in Netherlands. 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.
  - FeteCommuniste 7y ago
    Fertility rates across better-developed majority-Muslim countries have been plummeting: https://www.google.com/publicdata/explore?ds=d5bncppjof8f9_&met_y=sp_dyn_tfrt_in&idim=country:ARE:QAT:SAU&hl=en&dl=en#!ctype=l&strail=false&bcs=d&nselm=h&met_y=sp_dyn_tfrt_in&scale_y=lin&ind_y=false&rdim=region&idim=country:ARE:QAT:SAU:MAR:IRN:TUN:DZA:LBY:KWT:LBN&ifdim=region&hl=en_US&dl=en&ind=false https://www.google.com/publicdata/explore?ds=d5bncppjof8f9_&... 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.
    - car12 7y ago
      How is the statistic of lower dipping fertility rates inside Muslim countries of relevance when talking about: > 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.
raxxorrax 7y ago
If you want to know anything about future demographics, just look at a school. Should not be that hard honestly. 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.
barry-cotter 7y ago
Desire to have children has been under selection only since the demographic transition. Most of the world has less than two generations of selection, most one, some none. As such we would expect to see a lot of variation in desire to have children. The only group I’d be willing to bet money have notably higher desire to have children than other human populations are the French because that’s where the demographic transition started. For everyone else on average we should expect more or less the same mean and variance. 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.

benj111 7y ago

"how they reached the conclusion that fertility was heritable?" 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.

mynameishere 7y ago
It's beyond obvious. Strange that people are arguing against it. 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.
- j_wtf_all_taken 7y ago
  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?
  - benj111 7y ago
    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?
    - j_wtf_all_taken 7y ago
      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.

DissidentSci 7y ago

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. Here's a (now fairly old: from 2016) GWAS study on human reproductive behaviour: https://www.ncbi.nlm.nih.gov/pubmed/27798627 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.

j_wtf_all_taken 7y ago
> 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?

barry-cotter 7y ago

Every other psychological trait is heritable[1], why wouldn’t desire to have children be? [1]http://humancond.org/_media/papers/bouchard04_genetic_influence_psychological_traits.pdf 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.