That is completely untrue. When researchers have actually taken the time to do IQ testing in poor communities, they find a similar distribution of high and low IQ's as in the general population. There are a lot of 130 IQ people living in the slums.
Americans went from riches to soup lines (living in slums/squalor) over various periods of time. Though their IQ did not vary over that same time period.
A strong signal IQ is not, maybe a nice tailwind, but that doesn't help much if you are born in the bogs.