DOMINATIONConventional wisdom would attribute his survival at sea to “run-
ning on adrenaline.” In fact, the opposite was true. He wasn’t run-
ning on adrenaline; he was running on dopamine. During the intense
moments when he saved the boat, dopamine was in control and adren-
aline (called norepinephrine when it is inside the brain) was suppressed.
In the eighteenth century, Samuel Johnson summarized the situa-
tion like this: “When a man knows he is to be hanged in a fortnight, it
concentrates his mind wonderfully.” A more recent doctor, Dr. David
Caldicott, an emergency room physician at Calvary Hospital in Can-
berra, Australia, expressed it this way: “Emergency medicine is like
flying a plane. Hours of mundanity punctuated by moments of sheer
terror. If you’re worth your salt, you’re not scared, though. Just focused.”
IT’S EASIER TO KILL FROM A DISTANCEIn the science fiction classic Dune, by Frank Herbert, the hero has to
prove he is human by suppressing his animal instinct to act in the here
and now. His hand is placed in a diabolical contraption, a black box
that creates unimaginable pain. If he pulls his hand out of the box, the
old woman administering the test will pierce his neck with a poison nee-
dle, and he will die. She tells him, “You’ve heard of animals chewing off
a leg to escape a trap? That’s an animal kind of trick. A human would
remain in the trap, endure the pain, feigning death that he might kill
the trapper and remove a threat to his kind.”
Some people are naturally better at suppressing emotion than oth-
ers. In fact, they’re born that way, in part because of the number and
nature of their dopamine receptors, molecules in the brain that react
when dopamine is released. They differ based on genetics. Researchers
measured the density of dopamine receptors (how many there are, and
how closely they crowd together) in the brains of a variety of people,
and compared the results to tests that measured the person’s “emo-
tional detachment.”
The detachment test measured traits such as the tendency to avoid
sharing personal information and to become involved with other people.