Mastermind: How to Think Like Sherlock Holmes (31 page)

Learning to Spot the Signs of Overconfidence

Perhaps the best remedy for overconfidence is knowing when it is most likely to strike. Holmes, for one, knows how liable past success and experience are to cause a blunder in thought. It is precisely this knowledge
that lets him lay his master trap for the villain at the heart of the tragedies in
The Hound of the Baskervilles.
When the suspect learns that Sherlock Holmes has arrived at the scene, Watson worries that the knowledge will prove to make his capture all the more difficult: “I am sorry that he has seen you,” he tells Holmes. But Holmes is not so sure that it’s a bad thing. “And so was I at first,” he responds. But now he realizes that the knowledge, “may drive him to desperate measures at once. Like most clever criminals, he may be too confident in his own cleverness and imagine that he has completely deceived us.”

Holmes knows that the successful criminal is likely to fall victim to his very success. He knows to watch out for the red flag of cleverness that thinks itself too clever, thereby underestimating its opponents while overestimating its own strength. And he uses that knowledge in his capture of the villain on multiple occasions—not just at Baskerville Hall.

Spotting overconfidence, or the elements that lead to it, in others is one thing; identifying it in ourselves is something else entirely, and far more difficult. Hence Holmes’s Norbury blunders. Luckily for us, however, psychologists have made excellent headway in identifying where overconfidence most often lies in wait.

Four sets of circumstances tend to predominate. First, overconfidence is most common when facing difficulty: for instance, when we have to make a judgment on a case where there’s no way of knowing all the facts. This is called the hard-easy effect. We tend to be
under
confident on easy problems and
over
confident on difficult ones. That means that we underestimate our ability to do well when all signs point to success, and we overestimate it when the signs become much less favorable, failing to adjust enough for the change in external circumstances. For instance, in something known as the choice-50 (C50) task, individuals must choose between two alternatives and then state how confident they are in their choice, between 0.5 and 1. Repeatedly, researchers have found that as the difficulty of the judgment increases, the mismatch between confidence and accuracy (i.e., overconfidence) increases dramatically.

One domain where the hard-easy effect is prevalent is in the making of future predictions—a task that is nothing if not difficult (it is, as a matter of fact, impossible). The impossibility, however, doesn’t stop people
from trying, and from becoming a bit too confident in their predictions based on their own perceptions and experience. Consider the stock market. It’s impossible to actually predict the movement of a particular stock. Sure, you might have experience and even expertise—but you are nevertheless trying to predict the future. Is it such a surprise, then, that the same people who at times have outsized success also have outsized failures? The more successful you are, the more likely you are to attribute everything to your ability—and not to the luck of the draw, which, in all future predictions, is an essential part of the equation. (It’s true of all gambling and betting, really, but the stock market makes it somewhat easier to think you have an inside, experiential edge.)

Second, overconfidence increases with familiarity. If I’m doing something for the first time, I will likely be cautious. But if I do it many times over, I am increasingly likely to trust in my ability and become complacent, even if the landscape should change (overconfident drivers, anyone?). And when we are dealing with familiar tasks, we feel somehow safer, thinking that we don’t have the same need for caution as we would when trying something new or that we haven’t seen before. In a classic example, Ellen Langer found that people were more likely to succumb to the illusion of control (a side of overconfidence whereby you think you control the environment to a greater extent than you actually do) if they played a lottery that was familiar versus one that was unknown.

It’s like the habit formation that we’ve been talking about. Each time we repeat something, we become better acquainted with it and our actions become more and more automatic, so we are less likely to put adequate thought or consideration into what we’re doing. Holmes isn’t likely to pull a Yellow Face-style mess-up on his early cases; it’s telling that the story takes place later in his career, and that it seems to resemble a more traditional blackmail case, the likes of which he has experienced many times before. And Holmes knows well the danger of familiarity, at least when it comes to others. In “The Adventure of the Veiled Lodger,” he describes the experience of a couple who had fed a lion for too long. “It was deposed at the inquest that there has been some signs that the lion was dangerous, but, as usual, familiarity begat contempt, and no notice was taken of the fact.” All Holmes has to do is apply that logic to himself.

Third, overconfidence increases with information. If I know more about something, I am more likely to think I can handle it, even if the additional information doesn’t actually add to my knowledge in a significant way. This is the exact effect we observed earlier in the chapter with the clinicians who were making judgments on a case: the more information they had about the patient’s background, the more confident they were in the accuracy of the diagnosis, yet the less warranted was that confidence. As for Holmes, he has detail upon detail when he travels to Norbury But all the details are filtered through the viewpoint of Mr. Munro, who is himself unaware of the most important ones. And yet everything seems so incredibly plausible. Holmes’s theory certainly covers all of the facts—the known facts, that is. But Holmes doesn’t calibrate for the possibility that, despite the magnitude of the information, it continues to be
selective
information. He lets the sheer amount overwhelm what should be a note of caution: that he still knows nothing from the main actor who could provide the most meaningful information, Mrs. Munro. As ever, quantity does not equal quality.

Finally, overconfidence increases with action. As we actively engage, we become more confident in what we are doing. In another classic study, Langer found that individuals who flipped a coin themselves, in contrast to watching someone else flip it, were more confident in being able to predict heads or tails accurately, even though, objectively, the probabilities remained unchanged. Furthermore, individuals who chose their own lottery ticket were more confident in a lucky outcome than they were if a lottery ticket was chosen for them. And in the real world, the effects are just as pronounced. Let’s take the case of traders once again. The more they trade, the more confident they tend to become in their ability to make good trades. As a result, they often overtrade, and in so doing undermine their prior performance.

But forewarned is forearmed. An awareness of these elements can help you counteract them. It all goes back to the message at the beginning of the chapter: we must continue to learn. The best thing you can do is to acknowledge that you, too, will inevitably stumble, be it from stagnation or overconfidence, its closely related near opposite (I say
near
because overconfidence creates the illusion of movement, as opposed to
habitual stagnation, but that movement isn’t necessarily taking you anywhere), and to keep on learning.

As “The Yellow Face” draws to a close, Holmes has one final message for his companion. “Watson, if it should ever strike you that I am getting a little overconfident in my powers, or giving less pains to a case than it deserves, kindly whisper ‘Norbury’ in my ear, and I shall be infinitely obliged to you.” Holmes was right about one thing: he shouldn’t have missed the case for worlds. Even the best of us—especially the best of us—need a reminder of our fallibility and ability to deceive ourselves into a very confident blunder.

Now for the Good News:
It’s Never Too Late to Keep Learning, Even After You’ve Stopped.

We opened the chapter with “The Red Circle,” Holmes’s triumph of never-ending education. The year of that feat of undying curiosity and ever-present desire to continue to challenge the mind with new, more difficult cases and ideas? 1902.
⁴
As for the year of “The Yellow Face,” when victory of confidence over the very education Holmes urges befell the great detective? 1888.1 raise this chronology to point out one somewhat obvious and yet absolutely central element of the human mind: we never stop learning. The Holmes that took the case of a mysterious lodger and ended up embroiled in a saga of secret societies and international crime rings (for that is the meaning of Red Circle: a secret Italian crime syndicate with many evil deeds to its name) is no longer the same Holmes who made such seemingly careless errors in “The Yellow Face.”

Holmes may have his Norburys. But he has chosen to learn from them and make himself a better thinker in the process, ever perfecting a mind that already seems sharp beyond anything else. We, too, never stop learning, whether we know it or not. At the time of “The Red Circle,” Holmes was forty-eight years old. By traditional standards, we might have thought him incapable of any profound change by that point in life,
at least on the fundamental level of the brain. Until recently, the twenties were considered the final decade during which substantial neural changes could take place, the point where our wiring is basically complete. But new evidence points to an altogether different reality. Not only can we keep learning but our brains’ very structure can change and develop in more complex ways for far longer, even into old age.

In one study, adults were taught to juggle three balls over a three-month period. Their brains, along with those of matched non-juggling adults who received no training, were scanned at three points in time: before the training began, at a point when they reached juggling proficiency (i.e., could sustain the routine for at least sixty seconds), and three months after the proficiency point, during which time they were asked to stop juggling altogether. At first there were no differences in gray matter between jugglers and non-jugglers. By the time the jugglers had reached proficiency, however, a marked change was apparent: their gray matter had increased bilaterally (i.e., in both hemispheres) in the mid-temporal area and the left posterior intraparietal sulcus, areas associated with the processing and retention of complex visual-motion information. Not only were the jugglers learning, but so were their brains—and learning at a more fundamental level than previously thought possible.

What’s more, these neural changes can happen far more rapidly than we’ve ever realized. When researchers taught a group of adults to distinguish newly defined and named categories for two colors, green and blue, over a period of two hours (they took four colors that could be told apart visually but not lexically and assigned arbitrary names to each one), they observed an increase in gray-matter volume in the region of the visual cortex that is known to mediate color vision, V2/3. So in just two hours the brain was already showing itself receptive to new inputs and training, at a deep, structural level.

Even something that has been traditionally seen as the purview of the young—the ability to learn new languages—continues to change the landscape of the brain late into life. When a group of adults took a nine-month intensive course in modern standard Chinese, their brains’ white matter reorganized progressively (as measured monthly) in the left hemisphere
language areas and their right hemisphere counterparts—as well as in the
genu
(anterior end) of the corpus collosum, that network of neural fibers that connects the two hemispheres, which we encountered in the discussion of split-brain patients.

And just think of the rewiring that takes place in extreme cases, when a person loses his vision or function in some limb or undergoes some other drastic change in the body. Entire areas of the brain become reassigned to novel functions, taking up the real estate of the lost faculty in intricate and innovative ways. Our brains are capable of learning feats that are nothing short of miraculous.

But there’s more. It now seems clear that with application and practice even the elderly can reverse signs of cognitive decline
that has already occurred.
I place that emphasis out of pure excitement. How amazing to consider that even if we’ve been lazy all our lives, we can make a substantial difference and reverse damage that has already been done, if only we apply ourselves and remember Holmes’s most enduring lesson.

There is, of course, a downside in all this. If our brains can keep learning—and keep changing as we learn—throughout our lives, so, too, can they keep unlearning. Consider this: in that juggling study, by the time of the third scan, the gray-matter expansion that had been so pronounced three months prior had decreased drastically. All of that training? It had started to unravel at every level, performance and neural. What does that mean? Our brains are learning whether we know it or not. If we are not strengthening connections, we are losing them.

Our education might stop, if we so choose. Our brains’ never does. The brain will keep reacting to how we decide to use it. The difference is not whether or not we learn, but what and how we learn. We can learn to be passive, to stop, to, in effect, not learn, just as we can learn to be curious, to search, to keep educating ourselves about things that we didn’t even know we needed to know. If we follow Holmes’s advice, we teach our brains to be active. If we don’t, if we’re content, if we get to a certain point and decide that that point is good enough, we teach them the opposite.

SHERLOCK HOLMES FURTHER READING

“It’s a police matter, Mr. Holmes!” “It is art for art’s sake.”
from
His Last Bow
, “The Adventure of the Red Circle,” p. 1272.

“Come at once if convenient.” “As an institution I was like the violin, the shag tobacco, the old black pipe, the index books.”
from
The Memoirs of Sherlock Holmes
, “The Crooked Man,” p. 138.