The studies together indicate that math ability is inborn in many species, with number sense, mathematical skills and verbalability perhaps being separate talents in humans that we later learn to combine.
Proven and sustained communication (verbal and written) skills, including ability to prepare reports and conduct presentations on key issues by clearly formulating positions and issues, articulating options concisely, conveying, the maximum nescessary information, making and defending recommendations.
People who were asked to reflect on their many past successes or a specific failure scored roughly 10% better on tests of mathematical ability, as well as verbal, spatial, and abstract reasoning, than those who reflected on either many past failures or a single specific success.