Mastermind: How to Think Like Sherlock Holmes (3 page)

And that is something that not even every scientist acknowledges outright, so ingrained is it in his way of thinking. When a physicist dreams up a new experiment or a biologist decides to test the properties of a newly isolated compound, he doesn’t always realize that his specific question, his approach, his hypothesis, his very view of what he is doing would be impossible without the elemental knowledge at his disposal, that he has built up over the years. Indeed, he may have a hard time telling you from where exactly he got the idea for a study—and why he first thought it would make sense.

After World War II, physicist Richard Feynman was asked to serve on the State Curriculum Commission, to choose high school science textbooks for California. To his consternation, the texts appeared to leave students more confused than enlightened. Each book he examined was worse than the one prior. Finally, he came upon a promising beginning: a series of pictures, of a windup toy, an automobile, and a boy on a bicycle. Under each was a question: “What makes it go?” At last, he thought, something that was going to explain the basic science, starting with the fundamentals of mechanics (the toy), chemistry (the car), and biology (the boy). Alas, his elation was short lived. Where he thought to finally see explanation, real understanding, he found instead four words: “Energy makes it go.” But what was
that
? Why did it make it go? How did it make it go? These questions weren’t ever acknowledged, never mind answered. As Feynman put it, “That doesn’t
mean
anything. . . . It’s just a
word
!” Instead, he argued, “What they should have done is to look at the windup toy, see that there are springs inside, learn about springs, learn about wheels, and never mind ‘energy.’ Later on, when the children know
something about how the toy actually works, they can discuss the more general principles of energy.”

Feynman is one of the few who rarely took his knowledge base for granted, who always remembered the building blocks, the elements that lay underneath each question and each principle. And that is precisely what Holmes means when he tells us that we must begin with the basics, with such mundane problems that they might seem beneath our notice. How can you hypothesize, how can you make testable theories if you don’t first know what and how to observe, if you don’t first understand the fundamental nature of the problem at hand, down to its most basic elements? (The simplicity is deceptive, as you will learn in the next two chapters.)

The scientific method begins with a broad base of knowledge, an understanding of the facts and contours of the problem you are trying to tackle. In the case of Holmes in
A Study in Scarlet
, it’s the mystery behind a murder in an abandoned house on Lauriston Gardens. In your case, it may be a decision whether or not to change careers. Whatever the specific issue, you must define and formulate it in your mind as specifically as possible—and then you must fill it in with past experience and present observation. (As Holmes admonishes Lestrade and Gregson when the two detectives fail to note a similarity between the murder being investigated and an earlier case, “There is nothing new under the sun. It has all been done before.”)

Only then can you move to the hypothesis-generation point. This is the moment where the detective engages his imagination, generating possible lines of inquiry into the course of events, and not just sticking to the most obvious possibility—in
A Study in Scarlet
, for instance,
rache
need not be
Rachel
cut short, but could also signify the German for
revenge
—or where you might brainstorm possible scenarios that may arise from pursuing a new job direction. But you don’t just start hypothesizing at random: all the potential scenarios and explanations come from that initial base of knowledge and observation.

Only then do you test. What does your hypothesis imply? At this point, Holmes will investigate all lines of inquiry, eliminating them one by one until the one that remains, however improbable, must be the truth. And you will run through career change scenarios and try to play
out the implications to their logical, full conclusion. That, too, is manageable, as you will later learn.

But even then, you’re not done. Times change. Circumstances change. That original knowledge base must always be updated. As our environment changes, we must never forget to revise and retest out hypotheses. The revolutionary can, if we’re not careful, become the irrelevant. The thoughtful can become unthinking through our failure to keep engaging, challenging, pushing.

That, in a nutshell, is the scientific method: understand and frame the problem; observe; hypothesize (or imagine); test and deduce; and repeat. To follow Sherlock Holmes is to learn to apply that same approach not just to external clues, but to your every thought—and then turn it around and apply it to the every thought of every other person who may be involved, step by painstaking step.

When Holmes first lays out the theoretical principles behind his approach, he boils it down to one main idea: “How much an observant man might learn by an accurate and systematic examination of all that came his way.” And that “all” includes each and every thought; in Holmes’s world, there is no such thing as a thought that is taken at face value. As he notes, “From a drop of water, a logician could infer the possibility of an Atlantic or a Niagara without having seen or heard of one or the other.” In other words, given our existing knowledge base, we can use observation to deduce meaning from an otherwise meaningless fact. For what kind of scientist is that who lacks the ability to imagine and hypothesize the new, the unknown, the as-of-yet untestable?

This is the scientific method at its most basic. Holmes goes a step further. He applies the same principle to human beings: a Holmesian disciple will, “on meeting a fellow-mortal, learn at a glance to distinguish the history of the man and the trade or profession to which he belongs. Puerile as such an exercise may seem, it sharpens the faculties of observation, and teaches one where to look and what to look for.” Each observation, each exercise, each simple inference drawn from a simple fact will strengthen your ability to engage in ever-more-complex machinations. It will lay the groundwork for new habits of thinking that will make such observation second nature.

That is precisely what Holmes has taught himself—and can now teach us—to do. For, at its most basic, isn’t that the detective’s appeal? Not only can he solve the hardest of crimes, but he does so with an approach that seems, well, elementary when you get right down to it. This approach is based in science, in specific steps, in habits of thought that can be learned, cultivated, and applied.

That all sounds good in theory. But how do you even begin? It does seem like an awfully big hassle to always think scientifically, to always have to pay attention and break things down and observe and hypothesize and deduce and everything in between. Well, it both is and isn’t. On the one hand, most of us have a long way to go. As we’ll see, our minds aren’t meant to think like Holmes by default. But on the other hand, new thought habits can be learned and applied. Our brains are remarkably adept at learning new ways of thinking—and our neural connections are remarkably flexible, even into old age. By following Holmes’s thinking in the following pages, we will learn how to apply his methodology to our everyday lives, to be present and mindful and to treat each choice, each problem, each situation with the care it deserves. At first it will seem unnatural. But with time and practice it will come to be as second nature for us as it is for him.

Pitfalls of the Untrained Brain

One of the things that characterizes Holmes’s thinking—and the scientific ideal—is a natural skepticism and inquisitiveness toward the world. Nothing is taken at face value. Everything is scrutinized and considered, and only then accepted (or not, as the case may be). Unfortunately, our minds are, in their default state, averse to such an approach. In order to think like Sherlock Holmes, we first need to overcome a sort of natural resistance that pervades the way we see the world.

Most psychologists now agree that our minds operate on a so-called two-system basis. One system is fast, intuitive, reactionary—a kind of constant fight-or-flight vigilance of the mind. It doesn’t require much conscious thought or effort and functions as a sort of status quo auto pilot. The other is slower, more deliberative, more thorough, more logical—but also
much more cognitively costly. It likes to sit things out as long as it can and doesn’t step in unless it thinks it absolutely necessary.

Because of the mental cost of that cool, reflective system, we spend most of our thinking time in the hot, reflexive system, basically ensuring that our natural observer state takes on the color of that system: automatic, intuitive (and not always rightly so), reactionary, quick to judge. As a matter of course, we go. Only when something really catches our attention or forces us to stop or otherwise jolts us do we begin to know, turning on the more thoughtful, reflective, cool sibling.

I’m going to give the systems monikers of my own: the Watson system and the Holmes system. You can guess which is which. Think of the Watson system as our naive selves, operating by the lazy thought habits—the ones that come most naturally, the so-called path of least resistance—that we’ve spent our whole lives acquiring. And think of the Holmes system as our aspirational selves, the selves that we’ll be once we’re done learning how to apply his method of thinking to our everyday lives—and in so doing break the habits of our Watson system once and for all.

When we think as a matter of course, our minds are preset to accept whatever it is that comes to them. First we believe, and only then do we question. Put differently, it’s like our brains initially see the world as a true/false exam where the default answer is always
true
. And while it takes no effort whatsoever to remain in
true
mode, a switch of answer to
false
requires vigilance, time, and energy.

Psychologist Daniel Gilbert describes it this way: our brains
must
believe something in order to process it, if only for a split second. Imagine I tell you to think of pink elephants. You obviously know that pink elephants don’t actually exist. But when you read the phrase, you just for a moment had to picture a pink elephant in your head. In order to realize that it couldn’t exist, you had to believe for a second that it
did
exist. We understand and believe in the same instant. Benedict de Spinoza was the first to conceive of this necessity of acceptance for comprehension, and, writing a hundred years before Gilbert, William James explained the principle as “All propositions, whether attributive or existential, are believed through the very fact of being conceived.” Only after the conception
do we effortfully engage in disbelieving something—and, as Gilbert points out, that part of the process can be far from automatic.

In the case of the pink elephants the disconfirming process is simple. It takes next to no effort or time—although it still does take your brain more effort to process than it would if I said gray elephant, since counterfactual information requires that additional step of verification and disconfirmation that true information does not. But that’s not always true: not everything is as glaring as a pink elephant. The more complicated a concept or idea, or the less obviously true or false (
There are no poisonous snakes in Maine
. True or false? Go! But even that can be factually verified. How about:
The death penalty is not as harsh a punishment as life imprisonment
. What now?), the more effort is required. And it doesn’t take much for the process to be disrupted or to not occur altogether. If we decide that the statement sounds plausible enough as is (
sure; no poisonous snakes in Maine; why not?
), we are more likely than not to just let it go. Likewise, if we are busy, stressed, distracted, or otherwise depleted mentally, we may keep something marked as true without ever having taken the time to verify it—when faced with multiple demands, our mental capacity is simply too limited to be able to handle everything at once, and the verification process is one of the first things to go. When that happens, we are left with uncorrected beliefs, things that we will later recall as true when they are, in fact, false. (Are there poisonous snakes in Maine? Yes, as a matter of fact there are. But get asked in a year, and who knows if you will remember that or the opposite—especially if you were tired or distracted when reading this paragraph.)

What’s more, not everything is as black and white—or as pink and white, as the case may be—as the elephant. And not everything that our intuition
says
is black and white is so in reality. It’s awfully easy to get tripped up. In fact, not only do we believe everything we hear, at least initially, but even when we have been told explicitly that a statement is false
before we hear it
, we are likely to treat it as true. For instance, in something known as the correspondence bias (a concept we’ll revisit in greater detail), we assume that what a person says is what that person actually believes—and we hold on to that assumption even if we’ve been told explicitly that it
isn’t so; we’re even likely to judge the speaker in its light. Think back to the previous paragraph; do you think that what I wrote about the death penalty is my actual belief? You have no basis on which to answer that question—I haven’t given you my opinion—and yet, chances are you’ve already answered it by taking my statement
as
my opinion. More disturbing still, even if we hear something denied—for example,
Joe has no links to the Mafia
—we may end up misremembering the statement as lacking the negator and end up believing that Joe
does
have Mafia links—and even if we don’t, we are much more likely to form a negative opinion of Joe. We’re even apt to recommend a longer prison sentence for him if we play the role of jury. Our tendency to confirm and to believe just a little too easily and often has very real consequences both for ourselves and for others.