Jonah Lehrer would like to tinker with one of the brain's features:
We're stuck with a mind that reacts to the mundane mundane worries of modern life - a falling stock market, a troubled marriage, taking the SAT - with a powerful set of primal chemicals that, once upon a time, were reserved for moments of "fight or flight". In other words, we treat everything like an existential threat, which is why a multiple choice exam can leave us panicky and breathless. The hypothalamus, it turns out, is an excitable drama queen, suffusing the bloodstream with adrenaline and cortisol whenever things get a little uncertain or unpleasant.
The problem with this blunt reaction to stress - it's too often all or nothing - is that, as I've written numerous times, chronic stress is really bad for you. It causes chronic back pain, weakens the heart and kills brain cells.