Truth 25. Listen for the dog that doesn't bark

I recently had the opportunity to kayak down the Grand Canyon. There are plenty of real problems to worry about in that area. There are scorpions and 14 different kinds of rattlesnakes in the underbrush; a bite from any one of which might lead to a long and expensive helicopter ride out to a hospital. There are cliffs and rocks with the potential for broken limbs. And that's in addition to some of the biggest water in the West, which offers at least a small threat of drowning. In other words, my Grand Canyon kayaking trip offered plenty of ways to be injured or killed.

What actually almost killed me had nothing to do with the risks that I had identified before I left. It was not rattlesnakes or Class 10 rapids. (They use a different scale on the Colorado River.) It was a simple toe infection that came from wearing water shoes for 17 days. When I returned, I had such a severe infection that one toe swelled to three times its normal size. My doctor said I was at risk for a blood infection and probably should have been hospitalized. A series of horse needles full of antibiotics in my rear finally brought it under control. The dangers I had factored into my decision and that I had planned for were not the ones that I should have worried about most.

In Sir Arthur Conan Doyle's famous short story Silver Blaze, about the theft of a racehorse by the same name and the murder of its trainer, Sherlock Holmes points out to a Scotland Yard detective "the curious incident of the dog in the night-time." The detective replies, "The dog did nothing in the night-time." And Holmes replies, "That was the curious incident." The dog didn't bark because the beast knew the thief and murderer, which narrowed the list of suspects.

While Holmes is a fictional character, this type of information has serious implications in the real world. We are usually looking for the obvious signs—the smoking gun, the barking dog, the rushing rapids. We don't often ask ourselves, "What information is missing?" Sometimes, as with the barking dog, the missing information is just not there. Other times, there are people around us who make deliberate attempts to obscure it.

For example, how many people were killed in the war in Iraq in its first four years? If you said more than 3,000, you're only looking at part of the data. That was the number of U.S. military casualties by late 2006. The Iraqi civilians and security forces killed in the war topped 26,000 in October 2005, according to the official U.S. government count. It could actually have been as high as 70,000 or even higher by mid-2007.¹⁵ The data we look at are usually just U.S. casualties, but the broader data give a different picture of the war's impact. It could lead to different decisions if more attention were given to total casualties. This is the dog that didn't bark.

If I had been aware of the risk of toe infections on the Grand Canyon—so common it is called "toelio" by the river guides—I could have taken precautions to keep my feet dry. I could have treated myself in advance with antifungal creams, as I later found out that the more experienced among our crew had done. In other words, if I had "heard" the dog that didn't bark, I could have factored it into my decision or taken steps to keep it at bay.

When presented with a problem, we often accept the data as given. We collect it, or it is handed to us, and we then try to make the best sense of it. But to make better decisions, we need to begin asking, "What is missing? What can the missing data tell us? What one piece of information could change the way we look at this problem? Where can we get our hands on this information?" It may be that if we ignore the dog that doesn't bark, it could come back to bite us in the end.