Or intelligence is correlated with familial wealth because it is hereditary and smarter people tend to end up in more complex cognitively demanding professions which tend to pay more.
Maybe? The confounding factors are many. How to account for war (which often accrues wealth to the most brutal among the reasonably intelligent), disease (where selection is based on behavior, e.g., adherence to cultural norms, not necessarily intelligence), disparities in wealth across geography and culture (relative shifts in the normal distribution of IQ across demographics are reflected exactly in measures of wealth)? Let alone that procreation necessarily requires the joining of individuals who might have disparities in wealth, or intelligence, or both.
I tend to err on the side of caution with this one.
