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On Being Certain

Believing you are Right Even When You're Not

St. Martin's Press

The Feeling of Knowing

I AM STUCK IN AN OBLIGATORY NEIGHBORHOOD COCKTAIL party during the first week of the U.S. invasion of Iraq. A middle-aged, pin-striped lawyer announces that he'd love to be in the front lines when the troops reach Baghdad. "Door-to-door fighting," he says, puffing up his chest. He says he's certain he could shoot an Iraqi soldier, although he's never been in a conflict bigger than a schoolyard brawl.

"I don't know," I say. "I'd have trouble shooting some young kid who was being forced to fight."

"Not me. We're down to dog-eat-dog."

He nods at his frowning wife, who's anti-invasion. "All's fair in love and war." Then back to me. "You're not one of those peacenik softies, are you?"

"It wouldn't bother you to kill someone?"

"Not a bit."

"You're sure?"

"Absolutely."

He's a neighbor and I can't escape. So I tell him one of my father's favorite self-mocking stories.

During the 1930s and '40s, my father had a pharmacy in one of the tougher areas of San Francisco. He kept a small revolver hidden beneath the back cash register. One night, a man approached, pulled out a knife, and demanded all the money in the register. My father reached under the counter, grabbed his gun, and aimed it at the robber.

"Drop it," the robber said, his knife at my father's throat. "You're not going to shoot me, but I will kill you."

For a moment it was a Hollywood standoff, mano a mano. Then my father put down his gun, emptied out the register, and handed over the money.

"What's your point?" the lawyer asks. "Your father should have shot him."

"Just the obvious," I say. "You don't always know what you're going to do until you're in the moment."

"Sure you do. I know with absolute certainty that I'd shoot anyone who was threatening me."

"No chance of any hesitation?"

"None at all. I know myself. I know what I would do. End of discussion."

MY MIND REELS with seemingly impossible questions. What kind of knowledge is "I know myself and what I would do"? Is it a conscious decision based upon deep self-contemplation or is it a "gut feeling"? But what is a gut feeling-an unconscious decision, a mood or emotion, an ill-defined but clearly recognizable mental state, or a combination of all these ingredients? If we are tounderstand how we know what we know, we first need some ground rules, including a general classification of mental states that create our sense of knowledge about our knowledge.

For simplicity, I have chosen to lump together the closely allied feelings of certainty, rightness, conviction, and correctness under the all-inclusive term, the feeling of knowing. Whether or not these are separate sensations or merely shades or degrees of a common feeling isn't important. What they do share is a common quality: Each is a form of metaknowledge — knowledge about our knowledge — that qualifies or colors our thoughts, imbuing them with a sense of rightness or wrongness. When focusing on the phenomenology (how these sensations feel), I've chosen to use the term the feeling of knowing (in italics). However, when talking about the underlying science, I'll use knowing (in italics). Later I will expand this category to include feelings of familiarity and realness — qualities that enhance our sense of correctness.

EVERYONE IS FAMILIAR with the most commonly recognized feeling of knowing. When asked a question, you feel strongly that you know an answer that you cannot immediately recall. Psychologists refer to this hard-to-describe but easily recognizable feeling as a tip-of-the-tongue sensation. The frequent accompanying comment as you scan your mental Rolodex for the forgotten name or phone number: "I know it, but I just can't think of it." In this example, you are aware of knowing something, without knowing what this sense of knowing refers to.

Anyone who's been frustrated with a difficult math problem has appreciated the delicious moment of relief when an incomprehensible equation suddenly makes sense. We "see the light." This aha is a notification from a subterranean portion of our mind, an involuntary all-clear signal that we have grasped the heart of a problem. It isn't just that we can solve the problem; we also "know" that we understand it.

Most feelings of knowing are far less dramatic. We don't ordinarily sense them as spontaneous emotions or moods like love or happiness; rather they feel like thoughts — elements of a correct line of reasoning. We learn to add 2 + 2. Our teacher tells us that 4 is the correct answer. Yes, we hear a portion of our mind say. Something within us tells us that we "know" that our answer is correct. At this simplest level of understanding, there are two components to our understanding — the knowledge that 2 + 2 = 4, and the judgment or assessment of this understanding. We know that our understanding that 2 + 2 = 4 is itself correct.

The feeling of knowing is also commonly recognized by its absence. Most of us are all too familiar with the frustration of being able to operate a computer without having any "sense" of how the computer really works. Or learning physics despite having no "feeling" for the rightness of what you've learned. I can fix a frayed electrical cord, yet am puzzled by the very essence of electricity. I can pick up iron filings with a magnet without having the slightest sense of what magnetism "is."

At a deeper level, most of us have agonized over those sickening "crises of faith" when firmly held personal beliefs are suddenly stripped of a visceral sense of correctness, rightness, or meaning. Our most considered beliefs suddenly don't "feel right." Similarly, most of us have been shocked to hear that a close friend or relative has died unexpectedly, and yet we "feel" that he is still alive. Such upsetting news often takes time to "sink in." This disbelief associated with hearing about a death is an example of the sometimes complete disassociation between intellectual and felt knowledge.

To begin our discussion of the feeling of knowing, read the following excerpt at normal speed. Don't skim, give up halfway through, or skip to the explanation. Because this experience can't be duplicated once you know the explanation, take a moment to ask yourself how you feel about the paragraph. After reading the clarifying word, reread the paragraph. As you do so, please pay close attention to the shifts in your mental state and your feeling about the paragraph.

A newspaper is better than a magazine. A seashore is a better place than the street. At first it is better to run than to walk. You may have to try several times. It takes some skill, but it is easy to learn. Even young children can enjoy it. Once successful, complications are minimal. Birds seldom get too close. Rain, however, soaks in very fast. Too many people doing the same thing can also cause problems. One needs lots of room. If there are no complications, it can be very peaceful. A rock will serve as an anchor. If things break loose from it, however, you will not get a second chance.

Is this paragraph comprehensible or meaningless? Feel your mind sort through potential explanations. Now watch what happens with the presentation of a single word: kite. As you reread the paragraph, feel the prior discomfort of something amiss shifting to a pleasing sense of rightness. Everything fits; every sentence works and has meaning. Reread the paragraph again; it is impossible to regain the sense of not understanding. In an instant, without due conscious deliberation, the paragraph has been irreversibly infused with a feeling of knowing.

Try to imagine other interpretations for the paragraph. Suppose I tell you that this is a collaborative poem written by a third-grade class, or a collage of strung-together fortune cookie quotes. Your mind balks. The presence of this feeling of knowing makes contemplating alternatives physically difficult.

Each of us probably read the paragraph somewhat differently, but certain features seem universal. After seeing the word kite, we quickly go back and reread the paragraph, testing the sentences against this new piece of information. At some point, we are convinced. But when and how?

The kite paragraph raises several questions central to our understanding of how we "know" something. Though each will be discussed at greater length in subsequent chapters, here's a sneak preview.

• Did you consciously "decide" that kite was the correct explanation for the paragraph, or did this decision occur involuntarily, outside of conscious awareness?

• What brain mechanism(s) created the shift from not knowing to knowing?

• When did this shift take place? (Did you know that the explanation was correct before, during, or after you reread the paragraph?)

• After rereading the paragraph, are you able to consciously separate out the feeling of knowing that kite is the correct answer from a reasoned understanding that the answer is correct?

• Are you sure that kite is the correct answer? If so, how do you know?

How Do We Know What We Know?

PARENTS' AND TEACHERS' CUSTOMARY ADVICE FOR "NOT getting" math and physics is to study harder and think more deeply about the problem. Their assumption is that more effort will bridge the gap between dry knowledge and felt understanding. Without this assumption, we would give up every time we failed to understand something at first glance. But for those "what's the point of it all" existential moments — when formerly satisfactory feelings of purpose and meaning no longer "feel right"-history and experience have taught us differently. Logic and reason rarely are "convincing." (In this context, "convincing" is synonymous with reviving this missing "feeling of knowing what life is about.") Instead, we conjure up images of ascetics, mystics, and spiritual seekers — those who have donned hair shirts, trekked through the desert à la St. Jerome, huddled in caves or under trees, or sought isolation and silence in monasteries. Eastern religions emphasize a "stillness of the mind" rather than actively thinking about the missing sense of meaning.

So, which is it? Should the remedy for the absence of the feeling of knowing be more conscious effort and hard thought, or less? Or are both of these common teachings at odds with more basic neurobiology? Consider the curious phenomenon of blindsight, perhaps the best-studied example of the lack of the feeling of knowing in the presence of a state of knowledge.

Out of Sight Is Not Out of Mind

A patient has a stroke that selectively destroys his occipital cortex-the portion of the brain that receives primary visual inputs. His retina still records incoming information, but his malfunctioning visual cortex does not register the images sent from the retina. The result is that the patient consciously sees nothing. Now flash a light in various quadrants of his visual field. The patient reports that he sees nothing, yet he can fairly accurately localize the flashing light to the appropriate quadrant. He feels that he is guessing and is unaware that he is performing any better than by chance.

How is this possible?

First, let's trace the pathway of the "unseen" light. Some fibers from the retina proceed directly to the primary visual cortex in the occipital lobe. But other fibers bypass the region responsible for conscious "seeing" and instead project to subcortical and upper brain stem regions that do not produce a visual image. These lower brain areas are primarily concerned with automatic, reflexive functions such as fight-or-flight. Quickly approaching or looming objects cause the body to swing the head into position so that the eyes can examine the threat. An immediate reflexive action has clear evolutionary benefits over more time-consuming conscious perception and deliberation. In the broadest sense, you could say that these subcortical regions "see" the threat without sending a visual image into awareness.

Blindsight is a primitive unconscious visual localization and navigation system uncovered by the patient's cortical blindness. The patient's subliminal knowledge of the location of the flashing light doesn't trigger the feeling of knowing because news of this knowledge can't reach the higher cortical regions that generate the feeling. As a result, the patient swears that he hasn't seen a flashing light, yet he clearly possesses a subliminal knowledge of the light's location. When he chooses the proper visual field for the flashing light, he has no feeling that this is a correct answer. He does not know what he knows.

With blindsight, we see the disconnect between knowledge and awareness of this knowledge as being related to a fundamental flaw in our circuitry. This broken connection cannot be restored either through conscious effort or stilling of the mind-the problem is not within our control.

Though clinically apparent blindsight is a rare event usually caused by a stroke that interferes with the blood supply to the occipital cortex, faulty expressions of the feeling of knowing are everyday occurrences. Let's begin with our own memories.

The Challenger Study

Try to remember where you were when Kennedy was assassinated, the Challenger blew up, or the World Trade Center was attacked. Now ask yourself how certain you are of those memories. If you believe that you are quite sure of where you were when you heard the news, keep that feeling in mind as you read about the Challenger study in the next pages. If you don't remember where you were, ask yourself how you know that you don't remember. (Keep in mind the blindsight example when asking this question.) Either way, try to understand the feeling and your degree of certainty of this memory.

At my most recent med school reunion dinner, several former classmates were recalling where they were when Kennedy was assassinated. We had been in the second year of medical school, which meant that we all went to the same classes. Wherever one was, we probably all were. But the recollections were strikingly different; after dinner the discussion was becoming increasingly heated, as though each classmate's mind was on trial. A urologist thought we were at lunch, an internist said we were in the lab. A pathologist remembered being at a pub down the street from the med center. "That can't be true," the urologist said. "The assassination was at noon, Dallas time. You didn't go to the bars 'til after class."

I laughed and briefly described the Challenger study.

Within one day of the space shuttle Challenger explosion, Ulric Neisser, a psychologist studying "flashbulb" memories (the recall of highly dramatic events), asked his class of 106 students to write down exactly how they'd heard about the explosion, where they were, what they'd been doing, and how they felt. Two and a half years later they were again interviewed. Twenty-five percent of the students' subsequent accounts were strikingly different than their original journal entries. More than half the people had lesser degrees of error, and less than ten percent had all the details correct. (Prior to seeing their original journals, most students presumed that their memories were correct.)

Most of us reluctantly admit that memory changes over time. As kids, we saw how a story changed with retellings around a campfire. We have been at enough family reunions to hear once-familiar shared events morphed into unrecognizable and often contradictory descriptions. So, seeing that your journal entries were different than your recollection a couple of years later shouldn't be surprising. What startled me about the Challenger study were the students' responses when confronted with their conflicting accounts. Many expressed a high level of confidence that their false recollections were correct, despite being confronted with their own handwritten journals. The most unnerving was one student's comment, "That's my handwriting, but that's not what happened."

Why wouldn't the students consider their journal entries written shortly after the event to be more accurate than a recollection pulled up several years later? Pride, stubbornness, or fear of admitting an error? Not remembering the details of the Challenger explosion doesn't imply some massive personal failing that would make resistance to contrary evidence so overwhelming. Conversely, wouldn't pride in being logical and rational steer the students toward choosing their own handwriting over memories that they know might have been altered with time?

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Excerpted from On Being Certain by Robert A. Burton. Copyright © 2008 Robert A. Burton, M.D.. Excerpted by permission of St. Martin's Press.
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