This thread reminds me of the movie "Idiocracy".
It's definitely no longer a case of 'survival of the fittest'. In Australia the Government pays people to have kids. The Government also pays low income earners an ongoing subsidy for each child.
The smart, successful people can appreciate the long term costs (and don't get the subsidy), so don't usually have more than 2 kids.
The less educated the people and the lower the income, the more likely they are to be tempted by the new TV and other fun stuff they can buy for having another child.
The "Seven Deadly Sins"
Grains (wheat/rice/oats etc) . . . . . Dairy (milk/yogurt/butter/cheese etc) . . . . . Nightshades (peppers/tomato/eggplant etc)
Tubers (potato/arrowroot etc) . . . Modernly palatable (cashews/olives etc) . . . Refined foods (salt/sugars etc )
Legumes (soy/beans/peas etc)