A recent study measuring young Wall Street traders’ hormone levels as they brokered high-stakes deals: "the researchers showed that they tended to make more money on days when their testosterone levels were high. That suggests that the hormone makes them more likely to take profitable risks, but also that it may play a role in pumping up economic bubbles." And then there is the cortisol, which tends to make traders more cautious, helping to puncture speculative bubbles. So what’s the solution to this determinism? Take pills? The fellow conducting the study said this: "Banks and the financial system generally may be more stable if they had a greater diversity of endocrine profiles." Wall Street should hire more women and older men.