Unbeknownst to the men, in half the photos the eyes of the women were dilated, and in the other half they were not. The men were consistently more attracted to the women with dilated eyes. Remarkably, the men had no insight into their decision making. None of them said, “I noticed her pupils were two millimeters larger in this photo than in this other one.”

 

Instead, they simply felt more drawn toward some women than others, for reasons they couldn’t quite put a finger on. So who was doing the choosing? In the largely inaccessible workings of the brain, something knew that a woman’s dilated eyes correlates with sexual excitement and readiness. Their brains knew this, but the men in the study didn’t—at least not explicitly.

 

Brains are in the business of gathering information and steering behavior appropriately. It doesn’t matter whether consciousness is involved in the decision making. And most of the time, it’s not.

 

Consciousness developed because it was advantageous, but advantageous only in limited amounts.

 

You gleefully say, “I just thought of something!”, when in fact your brain performed an enormous amount of work before your moment of genius struck.

 

But you take credit without further wonderment at the vast, hidden machinery behind the scenes. And who can blame you for thinking you deserve the credit?

 

As Carl Jung put it, “In each of us there is another whom we do not know.” As Pink Floyd put it, “There’s someone in my head, but it’s not me.”

 

What is the position of your tongue in your mouth? Once you are asked the question you can answer it—but presumably you were not aware of the answer until you asked yourself. The brain generally does not need to know most things; it merely knows how to go out and retrieve the data. It computes on a need-to-know basis.

 

Helmholtz called this concept of vision “unconscious inference,” where inference refers to the idea that the brain conjectures what might be out there, and unconscious reminds us that we have no awareness of the process. We have no access to the rapid and automatic machinery that gathers and estimates the statistics of the world. We’re merely the beneficiaries riding on top of the machinery, enjoying the play of light and shadows.

 

To the reader of cuneiform, New Tai Lue, or Baluchi, the rest of the English script on this page looks as foreign and uninterpretable as their script looks to you. But these letters are effortless for you, because you’ve already turned the chore of cognitive translation into direct perception.

 

As we’ve seen, what we call normal perception does not really differ from hallucinations, except that the latter are not anchored by external input. Hallucinations are simply unfastened vision.

 

As early as the 1940s, thinkers began to toy with the idea that perception works not by building up bits of captured data, but instead by matching expectations to incoming sensory data.

 

What all this tells us is that perception reflects the active comparison of sensory inputs with internal predictions. And this gives us a way to understand a bigger concept: awareness of your surroundings occurs only when sensory inputs violate expectations. When the world is successfully predicted away, awareness is not needed because the brain is doing its job well.

 

Consciousness is the long-term planner, the CEO of the company, while most of the day-to-day operations are run by all those parts of her brain to which she has no access. Imagine a CEO who has inherited a giant blue-chip company: he has some influence, but he is also coming into a situation that has already been evolving for a long time before he got there. His job is to define a vision and make long-term plans for the company, insofar as the technology of the company is able to support his policies. This is what consciousness does: it sets the goals, and the rest of the system learns how to meet them.

 

A recent study by scientists in New Mexico counted up the tips made by lap dancers at local strip clubs and correlated this with the menstrual cycles of the dancers.31 During peak fertility, dancers raked in an average of $68 an hour. When they were menstruating, they earned only about $35. In between, they averaged $52. Although these women were presumably acting in a high capacity of flirtation throughout the month, their change in fertility was broadcast to hopeful customers by changes in body odor, skin, waist-to-hip ratio, and likely their own confidence as well. Interestingly, strippers on birth control did not show any clear peak in performance, and earned only a monthly average of $37 per hour (versus an average of $53 per hour for strippers not on birth control). Presumably they earned less because the pill leads to hormonal changes (and cues) indicative of early pregnancy, and the dancers were thus less interesting to Casanovas in the gentlemen’s clubs.

 

Some years ago, the psychologists Daniel Kahneman and Amos Tversky posed a deceptively simple question: If I were to offer you $100 right now or $110 a week from now, which would you choose? Most subjects chose to take $100 right then. It just didn’t seem worthwhile to wait an entire week for another $10. Then the researchers changed the question slightly: If I were to offer you $100 fifty-two weeks from now, or $110 fifty-three weeks from now, which would you choose? Here people tended to switch their preference, choosing to wait the fifty-three weeks. Note that the two scenarios are identical in that waiting one extra week earns you an extra $10. So why is there a preference reversal between the two?

 

That shape happens to look like the shape you would get if you combined two simpler processes: one that cares about short-term reward and one that holds concerns more distantly into the future.

 

KEEPING THE UNION TOGETHER: CIVIL WARS IN THE BRAIN DEMOCRACY

 

This idea of retrospective storytelling suggests that we come to know our own attitudes and emotions, at least partially, by inferring them from observations of our own behavior.39 As Gazzaniga put it, “These findings all suggest that the interpretive mechanism of the left hemisphere is always hard at work, seeking the meaning of events. It is constantly looking for order and reason, even when there is none—which leads it continually to make mistakes.”

 

What Douglas experienced is called anosognosia. This term describes a total lack of awareness about an impairment, and a typical example is a patient who completely denies their very obvious paralysis. It’s not that Justice Douglas was lying—his brain actually believed that he could move just fine. These fabrications illustrate the lengths to which the brain will go to put together a coherent narrative.

 

It turns out that alerting the system to contradictions relies critically on particular brain regions—and one in particular, called the anterior cingulate cortex.

 

Minds seek patterns. In a term introduced by science writer Michael Shermer, they are driven toward “patternicity”—the attempt to find structure in meaningless data.42 Evolution favors pattern seeking, because it allows the possibility of reducing mysteries to fast and efficient programs in the neural circuitry.

 

As long as the zombie subroutines are running smoothly, the CEO can sleep. It is only when something goes wrong (say, all the departments suddenly find that their business models have catastrophically failed) that the CEO is rung up. Think about when your conscious awareness comes online: in those situations where events in the world violate your expectations. When everything is going according to the needs and skills of your zombie systems, you are not consciously aware of most of what’s in front of you; when suddenly they cannot handle the task, you become consciously aware of the problem. The CEO scrambles around, looking for fast solutions, dialing up everyone to find who can address the problem best.

 

From an evolutionary point of view, the purpose of consciousness seems to be this: an animal composed of a giant collection of zombie systems would be energy efficient but cognitively inflexible. It would have economical programs for doing particular, simple tasks, but it wouldn’t have rapid ways of switching between programs or setting goals to become expert in novel and unexpected tasks. In the animal kingdom, most animals do certain things very well (say, prying seeds from the inside of a pine cone), while only a few species (such as humans) have the flexibility to dynamically develop new software.

 

Does the discovery of Whitman’s brain tumor modify your feelings about his senseless murdering? If Whitman had survived that day, would it adjust the sentencing you would consider appropriate for him? Does the tumor change the degree to which you consider it “his fault”? Couldn’t you just as easily be unlucky enough to develop a tumor and lose control of your behavior? On the other hand, wouldn’t it be dangerous to conclude that people with a tumor are somehow free of guilt, or that they should be let off the hook for their crimes? The man on the tower with the mass in his brain gets us right into the heart of the question of blameworthiness. To put it in the legal argot: was he culpable? To what extent is someone at fault if his brain is damaged in ways about which he has no choice? After all, we are not independent of our biology, right?

 

Average Number of Violent Crimes Committed Annually in the United States Offense Aggravated Assault Homicide Armed robbery Sexual assault Carrying the genes 3,419,000 14,196 2,051,000 442,000 Not carrying the genes 435,000 1,468 157,000 10,000 In other words, if you carry these genes, you’re eight times more likely to commit aggravated assault, ten times more likely to commit murder, thirteen times more likely to commit armed robbery, and forty-four times more likely to commit sexual assault.

 

About one-half of the human population carries these genes, while the other half does not, making the first half much more dangerous indeed. It’s not even a contest. The overwhelming majority of prisoners carry these genes, as do 98.4 percent of those on death row. It seems clear enough that the carriers are strongly predisposed toward a different type of behavior—and these statistics alone indicate that we cannot presume that everyone is coming to the table equally equipped in terms of drives and behaviors.

 

By the way, as regards that dangerous set of genes, you’ve probably heard of them. They are summarized as the Y chromosome. If you’re a carrier, we call you a male.

 

THE QUESTION OF FREE WILL, AND WHY THE ANSWER MAY NOT MATTER “Man is a masterpiece of creation, if only because no amount of determinism can prevent him from believing that he acts as a free being.” —Georg C. Lichtenberg, Aphorisms

 

The concept and word to replace blameworthiness is modifiability, a forward-looking term that asks, What can we do from here? Is rehabilitation available? If so, great. If not, will the punishment of a prison sentence modify future behavior? If so, send him to prison. If punishment won’t help, then take the person under state control for the purposes of incapacitation, not retribution.

 

FROM DETHRONEMENT TO DEMOCRACY After Galileo discovered the moons of Jupiter in his homemade telescope in 1610, religious critics decried his new sun-centered theory as a dethronement of man. They didn’t suspect that this was only the first dethronement of several. One hundred years later, the study of sedimentary layers by the Scottish farmer James Hutton toppled the Church’s estimate of the age of the Earth—making it eight hundred thousand times older. Not long afterward, Charles Darwin relegated humans to just another branch in the swarming animal kingdom. At the beginning of the 1900s, quantum mechanics irreparably altered our notion of the fabric of reality. In 1953, Francis Crick and James Watson deciphered the structure of DNA, replacing the mysterious ghost of life with something that we can write down in sequences of four letters and store in a computer. And over the past century, neuroscience has shown that the conscious mind is not the one driving the boat. A mere four hundred years after our fall from the center of universe, we have experienced the fall from the center of ourselves. In the first chapter we saw that conscious access to the machinery under the hood is slow, and often doesn’t happen at all. We then learned that the way we see the world is not necessarily what’s out there: vision is a construction of the brain, and its only job is to generate a useful narrative at our scales of interactions (say, with ripe fruits, bears, and mates).

 

In Chapter 5 we learned that minds contain multitudes, which explains why you can curse at yourself, laugh at yourself, and make contracts with yourself. And in Chapter 6 we saw that brains can operate quite differently when they are changed by strokes, tumors, narcotics, or any variety of events that alter the biology. This agitates our simple notions of blameworthiness.

 

Remember what we said earlier about having an 828 percent higher chance of committing a violent crime if you carry the Y chromosome? The statement is factual, but the important question to ask is this: why aren’t all males criminals? That is, only 1 percent of males are incarcerated.18 What’s going on?