One women is biologically incapable of feeling fear. Is she better off? (iStock)
Eve Fairbanks, a writer who lives in Johannesburg, is at work on a book about South Africa.

For the past six years I’ve traveled nearly incessantly: by car all over southern Africa; by plane to South America and the Middle East, through Wyoming by bicycle. Lately, though, every trip has felt harder. There’s the exhaustion of living out of a suitcase, developing rituals to keep track of my things that are so fastidious they’re almost religious, and which, like faith, inevitably fail. The fear of getting sick on the plane. The never knowing what I’m going to eat. The unpacking, which is worse than packing, and the never-fully-unpacking, which is easier but, like sweets on the physique, has a bad long-term effect on the spirit.

And yet, sometimes, the morning I get ready for travel, I feel all that lift. It’s as if the reluctance is a mist that miraculously dissolves, leaving pure eagerness. And I think: Doesn’t this happen so often? The bride who feels nervous for months before her wedding, and then, on the actual day, experiences total peace. The violinist pacing and sweating before a performance, only to be liberated into an expansive sense of control on stage. The neurologist Henry Marsh, writing in his recent memoir, describes “panic” and “almost a feeling of doom” before every surgery, which is reliably swept away at the very last moment by “fierce and happy concentration.”

What is the purpose of fear if it does this — dissolve when the feared thing is actually encountered? I’ve wondered this often. Fear’s transformation can make it seem pointless, a worthless emotion, even something that can make us angry. Why does dread have to curdle so many hours of our lives if, when the dreaded thing finally comes, we feel something else?

Some evolutionary psychologists believe fear has less and less purpose in contemporary life, now that we’re less likely to be struck down by a cheetah on the savanna. Xanax and Zen meditation alike promise us an experience of life more in keeping with the actual threats we now face, one freer from anxiety and fear.

But are we so wise to assume this emotion has no purpose? For the past 20 years, a neuroscientist named Daniel Tranel has studied a woman who suffers from a total calcification of the amygdala, the part of the brain that prompts the feeling of fear. This woman feels no fear at all. Does she have a life more wonderful than ours? In an interview she gave to NPR, it isn’t clear. She feels less anxiety, sure. But she describes her day-to-day experience not as exuberant but as level, kind of even — some days she’s a little up, some she’s a little blue.

Maybe fear is a preparation, the tensing of the inner bow before the arrow is released. Maybe it sometimes must prefigure the sense of release we also call joy.