Angelo," he said, and felt the bed rock as Angelo shuddered, caught halfway between REM atonia - the inhibition of movement caused by the shutdown of monoamines in the brain - and waking.

Chemistry is not destiny, certainly. But these scientists have demonstrated that the most reliable way to produce an adult who is brave and curious and kind and prudent is to ensure that when he is an infant, his hypothalamic-pituitary-adrenal axis functions well. And how do you do that? It is not magic. First, as much as possible, you protect him from serious trauma and chronic stress; then, even more important, you provide him with a secure, nurturing relationship with at least one parent and ideally two. That's not the whole secret of success, but it is a big, big part of it.