There IS a direct relationship, no matter how smart you try to seem about it.
Stupid and crazy people are pretty much always poor. No exceptions. If they happen to be rich, they got it through some inheritance or windfall, and as the saying goes, "A fool and his money are soon parted." They quickly lose it.
A person that is both smart AND rational, however, is required to even be rich. I'm not saying "all people who are smart and rational are rich" I am saying it's a minimum requirement. Other factors come into play such as ambition, other life values, ones driving goal in life, and to a degree some luck.