Absolutely untrue. In modern societies, the higher the income, the less likely the person is to reproduce. Thus, intellectual ability, to the extent it is hereditary, is if anything breeding itself out of the population. Most of the arguements were flawed but this one jumped out at me too.
One would wonder why there are more wildabeast in those Nat. Geo. specials than there are giraffes.[grin]
Wealthy people certainly have the resources to have more children than poor people, although the difference is slight in today's world. It's just that wealthy people today prefer to have fewer children. Birth control and abortion allow them to make their preference reality.
It's interesting that in surveys as late as mid-1800's Britain, the poverty line was defined as that income below which the family did not have enough food to feed all its children.