This short essay by Jared Diamond clarified something for me I sort of knew already:
This calculation illustrates the biggest single lesson that I’ve learned from 50 years of field work on the island of New Guinea: the importance of being attentive to hazards that carry a low risk each time but are encountered frequently.
He opens with the example of falling in the shower—a low risk at any given time, but considering how many times you shower the overall risk is surprisingly high. The example is so familiar it doesn’t have much power, but he goes on to another that drove the point home for me:
I first became aware of the New Guineans’ attitude toward risk on a trip into a forest when I proposed pitching our tents under a tall and beautiful tree. To my surprise, my New Guinea friends absolutely refused. They explained that the tree was dead and might fall on us.
Yes, I had to agree, it was indeed dead. But I objected that it was so solid that it would be standing for many years. The New Guineans were unswayed, opting instead to sleep in the open without a tent.
I thought that their fears were greatly exaggerated, verging on paranoia. In the following years, though, I came to realize that every night that I camped in a New Guinea forest, I heard a tree falling. And when I did a frequency/risk calculation, I understood their point of view.
Consider: If you’re a New Guinean living in the forest, and if you adopt the bad habit of sleeping under dead trees whose odds of falling on you that particular night are only 1 in 1,000, you’ll be dead within a few years. In fact, my wife was nearly killed by a falling tree last year, and I’ve survived numerous nearly fatal situations in New Guinea.
Diamond calls the New Guinean attitude (which he also adopts) “constructive paranoia”, a wariness about casually incurring unnecessary risk. He describes it as hypervigilance, a habitual attitude that he doesn’t allow to veer into obsessiveness:
My hypervigilance doesn’t paralyze me or limit my life: I don’t skip my daily shower, I keep driving, and I keep going back to New Guinea. I enjoy all those dangerous things. But I try to think constantly like a New Guinean, and to keep the risks of accidents far below 1 in 1,000 each time.
As I wind down this life I find myself tweaking my practices in this way all the time. It doesn’t cost me much to take measures to help prevent a fall—e.g. I started wearing house shoes instead of socks in the house (and find that I actually prefer the extra stability, not to mention the warmth!)—but the cost to others if I fell badly could be enormous—so why not?
Just yesterday morning was a good example, when we had our first snow of the season the night before. It was only an inch or so, and the temperature was in the mid-20s, something that my northern readers will laugh at. But down here they aren’t so great about clearing the roads, and icy spots would be found here and there. If I had needed to go to a job or an important appointment I would have gone without worry. But all I needed to do was go to the gym, something I do every morning, and skipping a day wouldn’t hurt anything. Now, I’m a creature of habit, partly driven by the fear that breaking a chain out of laziness or such may be a slippery slope towards failure. So ten or twenty years ago I probably would have worried more that my wariness was just an excuse, and made the trip just to keep from indulging myself. But constructive paranoia is dominant in me now, and I didn’t think twice about not going. As proven by the fact that it was in the low teens this morning, very cold for here, and the van windows were iced enough to need 10-15 minutes of work—but it had been clear and sunny yesterday so the roads were fine, and I didn’t think twice about braving the cold, chipping off the ice, and driving to the gym.