3 ms·

There is a wealth of data now that shows fertility declining with increased standard of living. (Lots of correlations obscure the exact causations, but among th

by sfink 7y ago

There is a wealth of data now that shows fertility declining with increased standard of living. (Lots of correlations obscure the exact causations, but among the correlations is female economic and social mobility.) Your example is an eminently plausible mechanism for the spread of high fertility via either genetic or social vectors - but given that it contradicts the data, I don't see how it can be any more than an anecdote. Perhaps the grandchildren of large families are sufficiently removed to revert to the social mean? I don't know. As for the Black Death, the personal and societal restrictions that result from not wanting to die from casual contact were probably quite a relief to escape and reverse. I don't know enough about history, but I could imagine that kicking off a positive chain reaction. After a cold season, people love to play in the sun. This part is just speculation on my part, though; you're welcome to continue siding with Thanos.

toasterlovin 7y ago
The mechanism is that the propensity to have more children is partly genetic. So as people with those genes out-breed the rest of the population, those genes come to predominate in the population. Thus overcoming the demographic transition. Here is a recent paper that models this: https://www.sciencedirect.com/science/article/pii/S1090513817302799 https://www.sciencedirect.com/science/article/pii/S109051381... The Black Death is pretty well accepted as a contributor to the end of feudalism. I guess you’re positing that somehow that would be the result of survivors feeling elated at having gotten past the catastrophe (which is a temporary emotion), versus their facing an easier life as a result of 50% of the population dying (an effect which lasts a lifetime). Seems implausible to me. But also, that the reduction in labor supply lead to vastly improved outcomes for laborers is pretty well attested. Lords of the manor started competing for labor because it was scarce. As a result, laborers were able to transition into owning their own property. It was a big deal. And it has to do with permanently reducing the population to well below the Malthusian limit (the plague periodically re-occurred for centuries, culling the population each time).
- philwelch 7y ago
  > The mechanism is that the propensity to have more children is partly genetic. So as people with those genes out-breed the rest of the population, those genes come to predominate in the population. Thus overcoming the demographic transition. Is this entirely a genetic thing or are there also cultural components? I’ve long entertained a crackpot theory that North America will be almost entirely Mormon or Roman Catholic in 200 years, partially for this reason. The only reservation being that secular-humanist culture seems to convert people from more traditional cultures even faster than they reproduce....
  - lliamander 7y ago
    > I’ve long entertained a crackpot theory that North America will be almost entirely Mormon or Roman Catholic in 200 years, partially for this reason. Or Muslim, although that's more likely in Europe at this point. > The only reservation being that secular-humanist culture seems to convert people from more traditional cultures even faster than they reproduce.... Perhaps in a few hundred years secular humanism will be seen a memetic Black Death.
  - toasterlovin 7y ago
    The heritability of fertility is about 50%, I believe. So about half of the variance in number of offspring is genetic. The remainder is other stuff: culture, chance, etc. I would imagine that the genetic component is multi faceted. Some of it might be a desire to have children. Some of it might be a resistance to certain ideas or lifestyles that result in fewer offspring (if that seems far fetched, consider first that political orientation is also about 50% heritable).
    - philwelch 7y ago
      But also consider that it’s hard to experimentally separate cultural and genetic influences because most children are raised and hence inculturated by at least one of their genetic parents.
      - toasterlovin 7y ago

by sfink 7y ago

toasterlovin 7y ago

The mechanism is that the propensity to have more children is partly genetic. So as people with those genes out-breed the rest of the population, those genes come to predominate in the population. Thus overcoming the demographic transition. Here is a recent paper that models this: https://www.sciencedirect.com/science/article/pii/S1090513817302799 https://www.sciencedirect.com/science/article/pii/S109051381... The Black Death is pretty well accepted as a contributor to the end of feudalism. I guess you’re positing that somehow that would be the result of survivors feeling elated at having gotten past the catastrophe (which is a temporary emotion), versus their facing an easier life as a result of 50% of the population dying (an effect which lasts a lifetime). Seems implausible to me. But also, that the reduction in labor supply lead to vastly improved outcomes for laborers is pretty well attested. Lords of the manor started competing for labor because it was scarce. As a result, laborers were able to transition into owning their own property. It was a big deal. And it has to do with permanently reducing the population to well below the Malthusian limit (the plague periodically re-occurred for centuries, culling the population each time).

philwelch 7y ago
> The mechanism is that the propensity to have more children is partly genetic. So as people with those genes out-breed the rest of the population, those genes come to predominate in the population. Thus overcoming the demographic transition. Is this entirely a genetic thing or are there also cultural components? I’ve long entertained a crackpot theory that North America will be almost entirely Mormon or Roman Catholic in 200 years, partially for this reason. The only reservation being that secular-humanist culture seems to convert people from more traditional cultures even faster than they reproduce....
- lliamander 7y ago
  > I’ve long entertained a crackpot theory that North America will be almost entirely Mormon or Roman Catholic in 200 years, partially for this reason. Or Muslim, although that's more likely in Europe at this point. > The only reservation being that secular-humanist culture seems to convert people from more traditional cultures even faster than they reproduce.... Perhaps in a few hundred years secular humanism will be seen a memetic Black Death.
- toasterlovin 7y ago
  The heritability of fertility is about 50%, I believe. So about half of the variance in number of offspring is genetic. The remainder is other stuff: culture, chance, etc. I would imagine that the genetic component is multi faceted. Some of it might be a desire to have children. Some of it might be a resistance to certain ideas or lifestyles that result in fewer offspring (if that seems far fetched, consider first that political orientation is also about 50% heritable).
  - philwelch 7y ago
    But also consider that it’s hard to experimentally separate cultural and genetic influences because most children are raised and hence inculturated by at least one of their genetic parents.
    - toasterlovin 7y ago