Brain Buys

by Dean Buonomano

  Technology affords us the opportunity to vicariously experience a vast assortment of dangers: fatal hurricanes, wars, plane crashes, deadly predators, and acts of terrorism. Whether these images are real or fictitious, part of the brain seems to treat these sightings as if they were firsthand observations. People can learn to fear pictures of angry faces or spiders even though the images were shown so quickly as to evade conscious perception. So it is not surprising that even if we are aware that the shark attack is not real, at some level our brain is forming unconscious associations, tainting our attitude about venturing into the ocean.

  AMYGDALA POLITICS

  Excessive fear of poisonous animals and predators can have a significant impact on the quality of life of individuals, but in the grand scheme of things, phobias are not the most serious consequence of our fear-related brain bugs. Rather, we should be most concerned about how vulnerabilities in our fear circuits are exploited by others. Well before and long after Machiavelli advised princes that it “is far safer to be feared than loved,”36 real or fabricated fear has provided a powerful tool to control public opinion, ensure loyalty, and justify wars. In the history of democracy there have probably been few elections in which candidates have not invoked fear of crime, outsiders, terrorists, immigrants, gangs, sexual predators, or drugs in an attempt to sway voters. The use of fear to influence opinion, or fearmongering, has been referred to as “amygdala politics” by Al Gore.37 Regarding the consequences of our susceptibility to fearmongering, he states:

  If [citizens’] leaders exploit their fears and use them to herd people in directions they might not otherwise choose, then fear itself can quickly become a self-perpetuating and free-wheeling force that drains national will and weakens national character, diverting attention from real threats deserving of healthy and appropriate concern, and sowing confusion about the essential choices that every nation must constantly make about its future.38

  The question is: why does fear hold such powerful sway? The answer lies in the ability of fear to override reason. Much of our fear circuitry was inherited from animals without much up front, that is, with little or no prefrontal cortex. The numerous areas that the prefrontal cortex comprises are involved in what we refer to as executive functions, including making decisions, maintaining attention, governing actions and intentions, and keeping certain emotions and thoughts in check.39 Ultimately our actions seem to be a group project; they are the product of negotiations between older brain areas, such as the amygdala, and the newer frontal modules. Together these areas may arrive at some consensus regarding the appropriate compromise between emotions and reason. But this balance is context-dependent, and at times it can be heavily biased toward emotions. The number of connections (axons) heading from the amygdala to cortical areas is larger than the number that arrive in the amygdala from the cortex. According to the neuroscientist Joe LeDoux: “As things now stand, the amygdala has a greater influence on the cortex than the cortex has on the amygdala, allowing emotional arousal to dominate and control thinking.”40

  The power of fear over reason is written in history. For example, in the months after the Japanese attacks on Pearl Harbor in December 1941, tens of thousands of Americans of Japanese ancestry were placed in internment camps in California. This reaction was not only irrational because it was deeply unjust, but because it was nonsensical to believe potential Japanese spies could be eliminated by rounding up all Japanese Americans on the West Coast (in 1988 the American government apologized and issued reparations of over $1 billion for its actions.

  There are many dangers in the world, and action and sacrifices are often needed to combat them. However, there is little doubt that in some cases our fears are amplified and distorted to the point of being completely irrational. An additional consequence of our fear-related brain bugs is that they drive innumerable misguided and foolish policy decisions.41 Take the fact that in 2001 five people died of exposure to anthrax after being contaminated through spores placed in letters (the source of the anthrax is believed to have been from the laboratory of Bruce Ivins, a biodefense expert at the U.S. Army Medical Research Institute for Infectious Disease).42 It has been estimated that the U.S. government spent $5 billion on security procedures in response to the anthrax-contaminated letters.43 The vision of terrorists using our own mail system to spread a horrific and fatal disease left little room for a rational analysis: it was already well established that, while deadly, anthrax was not a “good” bioweapon—in addition to the difficulties of safely generating large quantities of it and the fact that it can be destroyed by direct sunlight, it has to be aerolized into a very fine powder to be used effectively as a weapon.44 And in the end, the events did not appear to have anything to do with terrorism, but with a disturbed government employee. In retrospect the most effective, cheaper, and practical way to have prevented the five deaths would have been to shut down the U.S. Army laboratories in which the anthrax was made.

  In the past 100 years approximately 10,000 people have died as a result of military or terrorist attacks on American soil (most in Pearl Harbor and on 9/11), much less than the number of people who die in car accidents, of suicide, or heart disease in a single year. Yet, in 2007, the United States military spending was over $700 billion,45 while approximately $2 billion of federal funds were devoted to studying and curing heart disease.46 Does spending 250 times more money on something that is thousands of times less likely to kill us reflect a rational cost-benefit analysis, or does it reflect basic instincts involving fear of outsiders and territoriality gone awry?47

  Fear, of course, drives much more than security and military policies: fear also sells. As the sociologist Barry Glassner notes: “By fear mongering, politicians sell themselves to voters, TV and print news-magazines sell themselves to viewers and readers, advocacy groups sell memberships, quacks sell treatments, lawyers sell class-action lawsuits, and corporations sell consumer products.”48 The marketing of many products, from bottled water to antibacterial soaps, tap into our inherent fears of germs.

  There are two main causes of fear-related brain bugs. First, the genetic subroutines that determine what we are hardwired to fear were not only written for a different time and place, but also much of the code was written for a different species altogether. Our archaic neural operating system never received the message that predators and strangers are no longer as dangerous as they once were, and that there are more important things to fear. We can afford to fear predators, poisonous creatures, and people different from us less; and focus more on eliminating poverty, curing diseases, developing rational defense policies, and protecting the environment.

  The second cause of our fear-related brain bugs is that we are all too well prepared to learn to fear through observation. Observational learning evolved before the emergence of language, writing, TV, and Hollywood—before we were able to learn about things that happened in another time and place, or see things that never even happened in the real world. Because vicarious learning is in part unconscious, it seems to be partially resistant to reason and ill-prepared to distinguish fact from fiction. Furthermore, modern technology brings with it the ability to show people the same frightening event over and over again, presumably creating an amplified and overrepresented account of that event within our neural circuits.

  One of the consequences of our genetic baggage is that like the monkeys that are innately prepared to jump to conclusions about the danger posed by snakes, with minimal evidence we are ready and willing to jump to conclusions about the threat posed by those not from our tribe or nation. Tragically, this propensity is self-fulfilling: mutual fear flames mutual aggression, which in turn warrants mutual fear. However, as we develop a more intimate understanding of the neural mechanisms of fear and its bugs we will learn to better discriminate between the prehistoric whispers of our genes and the threats that are genuinely more likely to endanger our well-being.

  6

  Unreasonable Reasoning

  Intuition
can sometimes get things wrong. And intuition is what people use in life to make decisions.

  —Mark Haddon, The Curious Incident of the Dog in the Night-Time

  In the 1840s, in some hospitals, 20 percent of women died after childbirth. These deaths were almost invariably the result of puerperal fever (also called childbed fever): a disease characterized by fever, pus-filled skin eruptions, and generalized infection of the respiratory and urinary tracts. The cause was largely a mystery, but a few physicians in Europe and the United States hit upon the answer. One of them was the Hungarian doctor Ignaz Semmelweis. In 1846 Semmelweis noted that in the First Obstetric Clinic at the Viennese hospital, where doctors and students delivered babies, 13 percent of mothers died in the days following delivery (his carefully kept records show that on some months the rate was as high as 30 percent). However, in the Second Obstetric Clinic of the same hospital, where midwives delivered babies, the death rate was closer to 2 percent.

  As the author Hal Hellman recounts: “Semmelweis began to suspect the hands of the students and the faculty. These he realized, might go from the innards of a pustulant corpse almost directly into a woman’s uterus.”1 Semmelweis tested his hypothesis by instituting a strict policy regarding cleanliness and saw the puerperal fever rates plummet. Today his findings are considered to be among the most important in medicine, but two years after his initial study his strategy had still not been implemented in his own hospital. Semmelweis was not able to renew his appointment, and he was forced to leave to start a private practice. Although a few physicians rapidly accepted Semmelweis’s ideas, he and others were largely ignored for several more decades, and, by some estimates, 20 percent of the mothers in Parisian hospitals died after delivery in the 1860s. It was only in 1879 that the cause of puerperal fever was largely settled by Louis Pasteur.

  Why were Semmelweis’s ideas ignored for decades?2 The answer to this question is still debated. One factor was clearly that the notion of tiny evil life-forms, totally invisible to the eye, wreaking such havoc on the human body was so alien to people that it was considered preposterous. It has also been suggested that Semmelweis’s theory carried emotional baggage that biased physicians’ judgments: it required a doctor to accept that he himself had been an agent of death, infecting young mothers with a deadly disease. At least one physician at the time is reported to have committed suicide after coming to terms with what we know today as germ theory. There are undoubtedly many reasons germ theory was not readily embraced, but they are mostly the result of the amalgam of unconscious and irrational forces that influence our rational decisions.

  COGNITIVE BIASES

  The history of science, medicine, politics, and business is littered with examples of obstinate adherence to old customs, irrational beliefs, ill-conceived policies, and appalling decisions. Similar penchants are also observable in the daily decisions of our personal and professional lives. The causes of our poor decisions are complex and multifactorial, but they are in part attributable to the fact that human cognition is plagued with blind spots, preconceived assumptions, emotional influences, and built-in biases.

  We are often left with the indelible impression that our decisions are the product of conscious deliberation. It is equally true, however, that like a press agent forced to come up with a semirational explanation for the appalling behavior of his client, our conscious mind is often justifying decisions that have already been made by hidden forces. It is impossible to fully grasp the sway of these forces on our decisions; however, the persuasiveness of the unconscious is well illustrated by the sheer disconnect between conscious perception and reality that arises from sensory illusions.

  Both images of the Leaning Tower of Pisa shown in Figure 6.1 are exactly the same, yet the one on the right appears to be leaning more. The illusion is nonnegotiable; although I have seen it dozens of times, I still find it hard to believe that these are the same image. (The first time I saw it, I had to cut out the panel on the right and paste it on the left). The illusion is a product of the assumptions the visual system makes about perspective. When parallel lines, such as those of railroad tracks, are projected onto your retina, they converge as they recede into the distance (because the angle between the two rails progressively decreases). It is because your brain has learned to use this convergence to make inferences about distance that one can create perspective by simply drawing two converging lines on a piece of paper. The picture in the illusion was taken from the perspective of the bottom of the building, and since the lines of the tower do not converge in the distance (height in this case), the brain interprets this as meaning that the towers are not parallel, and creates the illusion of divergence.3

  Another well-known visual illusion occurs when you stare unwaveringly at a waterfall for 30 seconds or so, and then shift your gaze to look at unmoving rocks: the rocks appear to be rising. This is because motion is detected by different populations of neurons in the brain: “down” neurons fire in response to downward motion, and “up” neurons to upward movement. The perception of whether something is moving up or down is a result of the difference in the activity between these opposing populations of neurons—a tug-of-war between the up and down neurons. Even in the absence of movement these two populations have some level of spontaneous activity, but the competition between them is balanced. During the 30 seconds of constant stimulation created by the waterfall, the downward-moving neurons essentially get “tired” (they adapt). So when you view the stationary rocks, the normal balance of power has shifted, and the neurons that detect upward motion have a temporary advantage, creating illusory upward motion.

  Figure 6.1 The leaning tower illusion: The same exact picture of the Leaning Tower of Pisa is shown in both panels, yet the one on the right appears to be leaning more. (From [Kingdom et al., 2007].)

  Visual perception is a product of both experience and the computational units used to build the brain. The leaning tower illusion is a product of experience, of unconsciously learned inferences about angles, lines, distance, and two-dimensional images. The waterfall illusion is a product of built-in properties of neurons and neural circuits. And for the most part conscious deliberation does not enter into the equation: no matter how much I consciously insist the two towers are parallel, one tower continues to lean more than the other. Conscious deliberation, together with the unconscious traces of our previous experiences and the nature of the brain’s hardware, contribute to the decisions we make. Most of the time these multiple components collaborate to conjure decisions that are well suited to our needs; however, like visual perception, “illusions” or biases sometimes arise.

  Consider the subjective decision of whether you like something, such as a painting, a logo, or a piece of jewelry. What determines whether you find one painting more pleasing than another? For anybody who has “grown” to like a song, it comes as no surprise that we tend to prefer things that we are familiar with. Dozens of studies have confirmed that mere exposure to something, whether it’s a face, image, word, or sound, makes it more likely that people will later find it to be appealing.4 This familiarity bias for preferring things we are acquainted with is exploited in marketing; by repetitive exposure through ads we become familiar with a company’s product. The familiarity bias also seems to hold true for ideas. Another rule of thumb in decision making is “when in doubt, do nothing,” sometimes referred to as the status quo bias. One can imagine that the familiarity and status quo biases contributed to the rejection of Semmelweis’s ideas. Physicians resisted the germ theory in part because it was unfamiliar and ran against the status quo.

  Cognitive psychologists and behavioral economists have described a vast catalogue of cognitive biases over the past decades such as framing, loss aversion, anchoring, overconfidence, availability bias, and many others.5 To understand the consequences and causes of these cognitive biases, we will explore a few of the most robust and well studied.

  Framing and Anchoring

  The cognitive psychologists
Daniel Kahneman and Amos Tversky were among the most vocal whistleblowers when it came to exposing the flaws and foibles of human decision-making. Their research established the foundations of what is now known as behavioral economics. In recognition of their work Daniel Kahneman received a Nobel Memorial Prize in Economics in 2002 (Amos Tversky passed away in 1996). One of the first cognitive biases they described demonstrated that the way in which a question is posed—the manner in which it is “framed”—can influence the answer.

  In one of their classic framing studies, Kahneman and Tversky presented subjects with a scenario in which an outbreak of a rare disease was expected to kill 600 people.6 Two alternative programs to combat the outbreak were proposed, and the subjects were asked to choose between them: