How to Outsmart Your Brain's Hard-Wired Bad Habits

Quick decisions can get you killed, author Wray Herbert reveals in an excerpt from "On Second Thought."


Heuristics are cognitive rules of thumb, hard-wired mental shortcuts that everyone uses every day in routine decision-making and judgment. The study of heuristics is one of the most robust areas of scientific research today, producing hundreds of academic articles a year, yet the concept is little known outside the labs and offices of academia. This book is an attempt to remedy that.

Heuristics are normally helpful—indeed, they are crucial to getting through the myriad decisions we face every day without overthinking every choice. But they're imperfect and often irrational. They can be traps, as they were in the frozen mountain pass where Carruthers perished. Much has been written in the past couple of years about the wonders of the rapid, automatic human mind and gut-level decision-making. And indeed the unconscious mind is a wonder. But it is also perilous. The shortcuts that allow us to navigate each day with ease are the same ones that can potentially trip us up in our ordinary judgments and choices, in everything from health to finance to romance.

Most of us are not backcountry skiers, and we will probably never face the exact choices that Carruthers and his friends faced at Gobbler's Knob. But just because the traps are not life-threatening does not mean they aren't life-changing. Here are a few of the heuristics that shaped the backcountry skiers' poor choices—and may be shaping yours in ways you don't even recognize.

Consider the "familiarity heuristic." This is one of the cognitive shortcuts that McCammon identified as a contributing factor in many of the avalanche incidents he studied. The familiarity heuristic is one of the most robust heuristics known, and indeed one of the original heuristics identified and studied by pioneers in cognitive science. It is a potent mental tool that we draw on every day for hundreds of decisions, and basically what it says is this: If something comes quickly to mind, trust it. It must be available in your memory for a reason, so go with it. The basic rule of thumb is that familiar equals better equals safer.

Heuristics are amazing time-savers, which makes them essential to our busy lives. Many, like the familiarity heuristic, are an amalgam of habit and experience. We don't want to deliberate every minor choice we make every day, and we don't need to. But there are always risks when we stop deliberating. McCammon's avalanche victims, for example, were almost all experienced backcountry skiers, and indeed almost half had had some formal training in avalanche awareness.

This expertise didn't guarantee that they would make the smartest choices. Paradoxically, their expertise may have hurt them. They were so familiar with the terrain that it seemed safe—simply because it always had been safe before. It was familiar, and thus unthreatening. The skiers let down their guard because they all remembered successful outings that looked pretty much the same as the treacherous one. In fact, McCammon found in his research that there were significantly more avalanche accidents when the skiers knew the specific locale, compared to ski parties exploring novel terrain.

So familiarity and comfort can be traps. But the fact is, Carruthers' decision-making really started to go wrong long before he even started waxing his skis. It started back in the warmth of the living room, when he or one of his buddies said, "Hey, let's take a run out to Gobbler's Knob tomorrow." At that point, they triggered another powerful cognitive tool, known as the default heuristic or consistency heuristic. At that point, with their adventure still an abstract notion, they no doubt discussed the conditions, the pros and cons, and made a deliberate assessment of the risks of going out. But once they made that initial decision, the cold calculation stopped. They made a mental commitment, and that thought took on power.

We have a powerful bias for sticking with what we already have and not switching course. Unless there is some compelling reason not to, we let our minds default to what's given or what has already been decided. We rely on stay-the-course impulses all the time, often with good results. Constant switching can be perilous, in everything from financial matters to romantic judgments, so we have become averse to hopping around.