It's a Jungle in There: How Competition and Cooperation in the Brain Shape the Mind (29 page)

Dr. Neisser’s work showed that memory is a reconstruction of the past, not an accurate snapshot of it. … The mind, he said, conflates things. In a much-publicized experiment the day after the space shuttle Challenger exploded in 1986, Dr. Neisser asked students to write down their immediate experience upon hearing the news. Nearly three years later, he asked them to recount it. A quarter of the accounts were strikingly different, half were somewhat different, and less than a tenth had all the details correct. All were confident that their latter accounts were completely accurate. Another memory experiment compared the testimony of John W. Dean III, the former aide to President Richard M. Nixon, during the Senate Watergate hearings with tapes
of Mr. Dean’s conversations that the president had secretly recorded. He found discrepancies in detail after detail. But Dr. Neisser said the testimony was accurate about the most important truths: that there really had been a cover-up, and that Nixon did approve it.
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As the obituary indicates, misremembering reflects normalization. It can also reflect prejudice. In seminal research on the effects of prejudice on memory, other researchers showed people pictures of socially charged events. One image showed a white man holding up a black man at gunpoint. When the participants were later asked to recall what they saw, many of them recalled a black man holding up a white man. Prejudice led to the false memory. If the event had been real, the wrong person might have been accused of the crime. False arrests and convictions have occurred all too often for this reason.

Remembering wrongly can be affected by biases wrought
after
events are experienced as well as before. This possibility was demonstrated in another series of studies by Elizabeth Loftus. Here, she and John Palmer, both at the University of Washington at the time, showed participants a film of one car apparently having an accident with another.
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Later, the researchers asked different participants different leading questions, with the assignment of questions to subjects being random. The questions included the following. I have italicized the word that distinguished the questions from one another to help you see the differences. The experimenters did not change their vocal stress.

About how fast were the cars going when they
contacted
with each other?

About how fast were the cars going when they
hit
each other?

About how fast were the cars going when they
collided
with each other?

About how fast were the cars going when they
smashed
into each other?

The question the researchers were interested in was how fast the participants would say the cars were going depending on the word used in the question. The average speed estimates the participants gave were 31.8 miles per hour (mph) for “contacted,” 34.2 mph for “hit,” 39.8 mph for “collided,” and 40.8 mph for “smashed.” Thus, the more forceful the verb used to describe the event, the more quickly the participants remembered the cars as having traveled. Because the verbs were presented
after
the movies were watched, the subjects revised their memories after their memories were formed. This effect applied not just to speed but also to the appearance of the accident scene. The more forceful the verb, the higher the likelihood that subjects recalled seeing broken glass on the road. No broken glass ever appeared, however.

Results like these are unsettling if you believe you can trust your memories. If you, or your identity,
are
your memories but you can’t trust your own memories, who can you trust? That’s a question I can’t answer for you. All I can is say that this question is one each of us asks from time to time as we consider the rough-and-tumble world we live in. As if it’s not unsettling enough to remember that we live in a tough
outer
world, I’m now telling you that you live in, or house, a tough
inner
world as well. Perhaps inner toughness is optimally suited for the tough outer world we live in.
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If the same sorts of dynamics capture what goes on internally as well as externally, the way we remember may be best for both worlds.
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As with the other chapters of this book, I tried in this chapter to review the results of research on the topic at hand—learning and memory in this case—to see whether they could be understood in terms of Darwinian dynamics. What I presented can indeed be understood in Darwinian terms. The fact that this is so is hardly surprising given that the concepts and abilities acquired over the lifespan are adaptive; they are likely to help in everyday life. More importantly, the building blocks of these concepts and abilities get mixed and matched in ways that can give rise to the kinds of learning and memory phenomena reviewed here. These were only a subset of all the phenomena that could be discussed, of course. But no other phenomenon that I’m aware of in the domain of learning and memory vitiates the Darwinian view.

As a final remark, I want to mention that while I was preparing this chapter, I found out about a book I was unaware of before,
Beyond the Learning Curve: The Construction of Mind
, by Craig Speelman and Kim Kirsner (2005). Near the end of the book, the authors wrote the following:

The general principle in our theory of entities competing for survival, with the winners surviving to undertake future competition, and losers dying off, is wholly consistent with natural selection. … Thus, while biological evolution involves intergenerational changes or adaptation in species characteristics, intelligence and changes therein enable intra-generational adaptation in the behaviour of individuals [p 228].

Taking stock of this statement, we see once again that other investigators, after summarizing their field of specialization, appealed to Darwin’s theory. That Darwin’s idea extends so far and wide can hardly be accidental.

The sight of a man running through the streets wearing nothing but a bath towel and screaming deliriously is usually cause for concern. But if the man is yelling “Eureka!” and he happens to be an ancient Greek who has spent months pondering a problem for his king, his running through the streets and shouting at the top of his lungs could be cause for celebration.

The ancient Greek to whom I refer—Archimedes by name—had been approached by King Hiero II to determine whether a crown the king had received was solid gold. The question arose because the king had handed pure gold to a goldsmith for the crown’s creation, but when the king got the crown back, he suspected the goldsmith may have filched some of the precious metal, replacing it, the king feared, with some cheaper alloy. How to check the content of the crown without damaging it? That was the problem Hiero handed Archimedes. Hiero turned to Archimedes because Archimedes was the smartest of Hiero’s subjects. Archimedes, meanwhile, had his reputation on the line.

Archimedes thought long and hard about the problem, but to no avail. No matter how hard he thought, he always came up dry. Then one day, while settling into a bath, he noticed that the water rose as he lowered himself into the water. Such a common observation would have gone unnoticed by most people, but Archimedes’ mind had been preoccupied with matters related to volume measurement. Archimedes knew that the density of an object equals its volume divided by its mass. He also knew what the mass of the crown was and what the density of pure gold was. Archimedes understood that he could divide the mass of the crown by its volume to see whether the ratio of mass to volume—the crown’s density—matched the density of pure gold. What Archimedes didn’t know was how to estimate the crown’s volume. Archimedes and his fellow Greeks knew how to measure the volumes of regularly shaped objects like cubes and spheres; the formulas for doing so were among their proudest achievements. But they didn’t know how to measure the volumes of
irregularly shaped objects like crowns for kings, or bodies for mathematicians. The problem had befuddled him for months.

When Archimedes lowered himself into the tub and saw the water rise, he realized that the height to which the water rose was related to how much he displaced it. The water would rise more for a more voluminous body, Archimedes realized, and he appreciated that this would be true no matter what the body’s shape.

So excited was Archimedes by seeing the connection between water displacement and volume that, according to legend, he jumped out of the tub and ran through the streets shouting “Eureka!” That term means something like, “Whoopee! I’m so happy! I just figured out how to solve a nasty problem that’s been bugging me for ages!”

The history of problem-solving is filled with examples of people reaching solutions in the seemingly paradoxical way that Archimedes did—being unable at first to solve the problem and then having the solution come to them as if from the blue. Solutions don’t come from thin air, of course. They come from gray matter and white matter in the brain. How this happens is the problem cognitive psychologists have sought to solve while bathing, so to speak, in their own data and theories.

Cognitive psychologists have used the word “aha” to refer to the moment when the transition happens from not seeing a solution to seeing it. A challenge for cognitive psychologists is to understand how aha moments come about. Another challenge is to check whether aha moments are epiphenomenal. Are they, in other words, extraneous moments of joy that happen to coincide with finding solutions, or are they events critical to hitting on the solutions themselves? Are problems solved in bursts, or are they solved gradually?

In considering this question, I had something of an aha moment when I realized that the jungle principle could shed light on problem-solving itself. I realized it could because the jungle principle provides a useful metaphor for thinking about the search for solutions. The idea was that cognitive demons can collectively embody solutions to problems, but for the right cadre of cognitive demons to form, they must be activated to the point that they yield insights that previously were out of reach. Groups of cognitive demons that represent solutions may be suppressed by other more dominant demons, not because those other demons feared the repercussions of the solutions about to unfold—the solutions were not yet recognized, after all—but because the business of the demons already in control was more pressing, more worthwhile, than the business of the demons not yet unionized. If the neural environment fails to favor unions that permit problem solutions, they’re not selected for. But once a coalition of cranial creatures comes together in a way
that’s fortuitous, the system as a whole can move from a state of “Yuk, I’m stuck!” to a state of “Aha, I’m in luck!”

When Archimedes dipped into his bath and had his eureka moment, he was not, as far as I know, filthy from weeks of non-bathing. Presumably, he had taken baths prior to the bath that figuratively knocked his socks off. When he bathed prior to his eureka experience, Archimedes was unimpressed by the waxing and waning of his bathwater. Merely seeing the water rise and fall in those earlier ablutions didn’t trigger his recognition of the solution he sought. But something changed in Archimedes’ mind when he saw the solution. What was it?

Cognitive psychologists who study problem-solving say that problem-solving benefits from
incubation
. Their idea is that solutions not yet found are like chicks not yet hatched. A hen sitting on her egg provides the egg-bound chick with the heat and protection it needs to grow and ultimately break out of its shell. Cognitive psychologists say that solutions to problems are like that. Like chicks in their eggs, solutions to problems not yet solved need the right milieu to spring forth. Only when solutions are sufficiently mature will they be realized.

Other anecdotes besides the one concerning Archimedes provide further support for the incubation view. Consider an experience of the great French mathematician, Henri Poincaré. This giant of mathematics, whose work laid the foundations for modern dynamical systems theory, worked on a difficult problem for a long time and couldn’t solve it. Faced with this frustrating state of affairs, Poincaré did what any reasonable Frenchman would do: He went on vacation. The holiday had a happy effect, as Poincaré later reported:

Then I turned my attention to the study of some arithmetical questions apparently without much success and with a suspicion of any connection with my preceding researches. Disgusted by my failure, I went to spend a few days at the seaside, and thought of something else. One morning, walking on the bluff, the idea came to me, with just the same characteristics of brevity, suddenness, and immediate certainty, that the arithmetic transformations of indeterminate ternary quadratic forms were identical with those of non-Euclidean geometry.
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It turns out that Poincaré was not alone in having a solution find him, so to speak, rather than the other way around. Other notable thinkers have had
similar experiences, and they continue to do so. For example, while I was working on this chapter,
Science
magazine ran an advertisement for a website created by its parent organization, the American Association for the Advancement of Science. The advertisement showed the inventor of the vaccine patch, Carl Alving, along with a quote about how he came up with his medical breakthrough. “A dream told me to do it,” Alving said in the ad, which ran for several issues.
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Experiments have shown that incubation is a real phenomenon and not one limited to luminaries like Archimedes, Poincaré, or Alving. Incubation helps ordinary folks solve mundane problems like crossword puzzles, riddles, and other amusement problems.
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Take the “cheap necklace” problem. The challenge here is to create a single necklace out of four 3-link segments given three constraints: (1) It costs 2 cents to open a link, (2) it costs 3 cents to close a link, and (3) no more than 15 cents can be spent altogether. Think about this problem and see if you can solve it. It’s challenging. There’s a good chance you won’t be able to find a solution immediately if you’re like most people. The solution is given in the note referred to here.
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