Our main finding is that risk aversion and impatience both vary systematically with cognitive ability. Individuals with higher cognitive ability are significantly more willing to take risks in the lottery experiments and are significantly more patient over the year-long time horizon studied in the intertemporal choice experiment.
The link is here, gated for most of you (non-gated is here), and the authors are Thomas Dohmen, Armin Falk, David Huffman, and Uwe Sunde. The subjects, by the way, were Germans. The results held somewhat less strongly for females and younger individuals.