are you saying they have kids in order to have someone support them? if you are poor you should have less no more kids.
Usually, poverty tends to be worst in areas where the means of economic survival are labor-intensive and long-term care is done by the family unit. In places with high mortality rate, survival is also dependent on making sure deaths can be compensated for.
Without industries or economic sectors that provide wealth based on advanced education--things which take significant per-child investment, more can be gained with menial labor, which can start young, requires less schooling, and gains more capital with larger numbers of kids.
It's only when the economy moves beyond that phase that the equation shifts in favor of fewer kids with more invested in each.
Cultures and events can shift this. Agrarian and pastoral cultures favor large families, in part because doing so allowed their survival.
Areas where political tensions are high often have higher birth rates, as rival factions try to keep numbers in balance.
works both ways. only the buffoons 'think' making a kid is an evolutionary success. survival of the fittest can ONLY apply if there is NO welfare.
Survival of the fittest does not mean survival of the most self-reliant or capable. It is the persistence of traits and patterns that work to perpetuate themselves.
It is incorrect to think that Darwinian evolutionary trends match our desire to glorify traits we personally hold dear.
As long as welfare exists and it provides such a large amount of capital for large families that it enables the creation of even more families, a welfare-supported family will be more fit than one that has fewer kids without.