It's natural that you'd have more brains going into money management. There are so many huge incomes in money management and investment banking - it's like ants to sugar. There are huge incentives for a man to take up money management as opposed to, say, physics, and it's a lot easier.
We still know so little about how the brain interacts with the body chemistry or, for that matter, whether we should be talking about the brain or the mind, that it would be perilous to hazard any guess about the way Abraham Lincoln's biological health may or may not have affected him. Of course, we don't have Lincoln on hand to ask him directly; but even if we did, we still might not be able to make sense of how all the parts worked together.